Special Issue "Nutrition, Health and Athletic Performance"

A special issue of Nutrients (ISSN 2072-6643).

Deadline for manuscript submissions: closed (31 August 2016).

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Dr. Kelly Pritchett
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Guest Editor
Department of Nutrition, Exercise, and Health Sciences, Central Washington University, 400 East University Way, Ellensburg, WA 98926, USA
Interests: sports nutrition; post exercise nutrition and recovery; carbohydrates and exercise; female athlete triad; energy availability; vitamin D and athletic performance
Special Issues and Collections in MDPI journals
Dr. Enette Larson Meyer
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Guest Editor
Associate Professor, Department of Family and Consumer Sciences (Human Nutrition), University of Wyoming, Laramie, WY, USA
Interests: the health and performance of active individuals, particularly women, at all stages of the lifecycle and at all levels of performance—from the casual exerciser to the elite athlete

Special Issue Information

Dear Colleagues,

Optimal nutrition is fundamental for enhancing training, recovery and performance in sport. Therefore, research has aimed to determine the efficacy of appropriate intake of nutrients, fluids, and supplements and their role in exercise performance. The purpose of this Special Issue entitled “Nutrition, Health and Athletic Performance” is to highlight recent research examining aspects of sports nutrition and exercise performance. Manuscript submissions of original research, meta-analyses, or reviews of the scientific literature, which targets nutritional strategies to benefit performance and health, are welcome. Studies performed in humans are preferred given the applied nature of this issue.

Dr. Kelly Pritchett
Dr. Enette Larson-Meyer
Guest Editors

Manuscript Submission Information

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Keywords

  • carbohydrate
  • protein (synthesis)
  • performance
  • glycogen (resynthesis)
  • exercise recovery
  • ergogenic aids/supplements
  • hydration
  • pre-exercise feeding
  • athletes
  • nutrition for training
  • vitamins and minerals
  • fat (metabolism)

Published Papers (36 papers)

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Open AccessArticle
Effects of Carbohydrate and Glutamine Supplementation on Oral Mucosa Immunity after Strenuous Exercise at High Altitude: A Double-Blind Randomized Trial
Nutrients 2017, 9(7), 692; https://doi.org/10.3390/nu9070692 - 03 Jul 2017
Cited by 3
Abstract
This study analyzed the effects of carbohydrate and glutamine supplementation on salivary immunity after exercise at a simulated altitude of 4500 m. Fifteen volunteers performed exercise of 70% of VO2peak until exhaustion and were divided into three groups: hypoxia placebo, hypoxia 8% [...] Read more.
This study analyzed the effects of carbohydrate and glutamine supplementation on salivary immunity after exercise at a simulated altitude of 4500 m. Fifteen volunteers performed exercise of 70% of VO2peak until exhaustion and were divided into three groups: hypoxia placebo, hypoxia 8% maltodextrin (200 mL/20 min), and hypoxia after six days glutamine (20 g/day) and 8% maltodextrin (200 mL/20 min). All procedures were randomized and double-blind. Saliva was collected at rest (basal), before exercise (pre-exercise), immediately after exercise (post-exercise), and two hours after exercise. Analysis of Variance (ANOVA) for repeated measures and Tukey post hoc test were performed. Statistical significance was set at p < 0.05. SaO2% reduced when comparing baseline vs. pre-exercise, post-exercise, and after recovery for all three groups. There was also a reduction of SaO2% in pre-exercise vs. post-exercise for the hypoxia group and an increase was observed in pre-exercise vs. recovery for both supplementation groups, and between post-exercise and for the three groups studied. There was an increase of salivary flow in post-exercise vs. recovery in Hypoxia + Carbohydrate group. Immunoglobulin A (IgA) decreased from baseline vs. post-exercise for Hypoxia + Glutamine group. Interleukin 10 (IL-10) increased from post-exercise vs. after recovery in Hypoxia + Carbohydrate group. Reduction of tumor necrosis factor alpha (TNF-α) was observed from baseline vs. post-exercise and after recovery for the Hypoxia + Carbohydrate group; a lower concentration was observed in pre-exercise vs. post-exercise and recovery. TNF-α had a reduction from baseline vs. post-exercise for both supplementation groups, and a lower secretion between baseline vs. recovery, and pre-exercise vs. post-exercise for Hypoxia + Carbohydrate group. Five hours of hypoxia and exercise did not change IgA. Carbohydrates, with greater efficiency than glutamine, induced anti-inflammatory responses. Full article
(This article belongs to the Special Issue Nutrition, Health and Athletic Performance) Printed Edition available
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Open AccessArticle
Nutrition Assessment of B-Vitamins in Highly Active and Sedentary Women
Nutrients 2017, 9(4), 329; https://doi.org/10.3390/nu9040329 - 26 Mar 2017
Cited by 2
Abstract
Background: Female athletes and active women require adequate nutrition for optimal health and performance. Nutrition assessments are needed to identify potential nutrients of concern. Folate, vitamin B6, and vitamin B12 function in important pathways used during physical activity and female athletes may be [...] Read more.
Background: Female athletes and active women require adequate nutrition for optimal health and performance. Nutrition assessments are needed to identify potential nutrients of concern. Folate, vitamin B6, and vitamin B12 function in important pathways used during physical activity and female athletes may be at risk for poor status of these micronutrients. This cross-sectional study described a comprehensive nutrition assessment of the B-vitamins (folate, vitamin B6, and vitamin B12) using both dietary (food and dietary supplements) and biochemical assessments among highly active and sedentary women. Methods: Highly active (n = 29; age 20 ± 2 years; body mass index (BMI) 23.8 ± 3.5 kg/m2) and sedentary (n = 29; age 24 ± 3 years; BMI 22.6 ± 3.0 kg/m2) women were recruited for this study. Participants completed 7-day weighed food records and a fasting blood draw. Results: Although the highly active women reported higher intakes of energy (p < 0.01), folate (p < 0.01), vitamin B6 (p < 0.01), and vitamin B12 (p < 0.01), no significant differences were found between the groups for biomarkers of folate, vitamin B6, and vitamin B12. All of the highly active women had biomarkers within the desired reference ranges, suggesting good status. In general, most participants were able to meet the 1998 Recommended Daily Allowance (RDA) from food alone. For the women that reported using dietary supplements, micronutrient intakes met the 1998 RDA and in some cases, exceeded the Tolerable Upper Intake Level. Conclusion: This nutrition assessment documented good status for folate, vitamin B6, and vitamin B12 in the highly active women. Similar assessment approaches (food, dietary supplements, and biomarkers) should to completed with other nutrients of concern for the female athlete. Full article
(This article belongs to the Special Issue Nutrition, Health and Athletic Performance) Printed Edition available
Open AccessArticle
Comparison of Site-Specific Bone Mineral Densities between Endurance Runners and Sprinters in Adolescent Women
Nutrients 2016, 8(12), 781; https://doi.org/10.3390/nu8120781 - 30 Nov 2016
Cited by 4
Abstract
We aimed to compare site-specific bone mineral densities (BMDs) between adolescent endurance runners and sprinters and examine the relationship of fat-free mass (FFM) and nutrient intake on BMD. In this cross-sectional study, 37 adolescent female endurance runners and sprinters (16.1 ± 0.8 years) [...] Read more.
We aimed to compare site-specific bone mineral densities (BMDs) between adolescent endurance runners and sprinters and examine the relationship of fat-free mass (FFM) and nutrient intake on BMD. In this cross-sectional study, 37 adolescent female endurance runners and sprinters (16.1 ± 0.8 years) were recruited. BMD and FFM were assessed by dual-energy X-ray absorptiometry. Nutrient intake and menstrual state were evaluated by questionnaires. After adjusting for covariates, spine and total bone less head (TBLH) BMDs were significantly higher in sprinters than endurance runners (TBLH, 1.02 ± 0.05 vs. 0.98 ± 0.06 g/cm2; spine, 0.99 ± 0.06 vs. 0.94 ± 0.06 g/cm2; p < 0.05). There was no significant difference between groups in other sites. The rate of menstrual abnormality was higher in endurance runners compared with sprinters (56.3% vs. 23.8%; p < 0.05). FFM was a significant covariate for BMD on all sites except the spine (p < 0.05). Dietary intake of vitamin D was identified as a significant covariate only for pelvic BMD (p < 0.05). The BMDs of different sites among endurance runners and sprinters were strongly related to FFM. However, the association of FFM with spine BMD cannot be explained by FFM alone. Other factors, including nutrition and/or mechanical loading, may affect the spine BMD. Full article
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Open AccessArticle
Vitamin D and Weight Cycling: Impact on Injury, Illness, and Inflammation in Collegiate Wrestlers
Nutrients 2016, 8(12), 775; https://doi.org/10.3390/nu8120775 - 30 Nov 2016
Cited by 5
Abstract
This study explored the link between vitamin D status and frequency of skin infections, inflammation, and injury in college wrestlers during an academic year. Methods: Serum 25-hydroxyvitamin D (25(OH)D) (n = 19), plasma cytokine (TNF-α, IL-6, IL-10) (n = 18) concentrations, [...] Read more.
This study explored the link between vitamin D status and frequency of skin infections, inflammation, and injury in college wrestlers during an academic year. Methods: Serum 25-hydroxyvitamin D (25(OH)D) (n = 19), plasma cytokine (TNF-α, IL-6, IL-10) (n = 18) concentrations, and body weight/composition were measured and injury/illness/skin infection data were collected in fall, winter, and spring. Results: In the fall, 74% of wrestlers had vitamin D concentrations <32 ng/mL which increased to 94% in winter and spring. Wrestlers lost an average of 3.4 ± 3.9 kg (p < 0.001) during the season with corresponding decreases in fat mass and increases in lean mass (p < 0.01). An inverse association between 25(OH)D concentrations and total body mass and body fat percentage was observed at all-time points (p < 0.01). Concentrations of cytokines were highly variable among individuals and did not change across time (p > 0.05). Correlations between vitamin D status, cytokines, or frequency of illness, injury, or skin infections were not observed. Conclusions: A high prevalence of vitamin D insufficiency (<32 ng/mL) and deficiency (<20 ng/mL) was observed in wrestlers and was associated with higher adiposity. It remains unclear if higher vitamin D status would reduce injury, illness, and skin infection risk. Full article
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Open AccessArticle
Periodization of Carbohydrate Intake: Short-Term Effect on Performance
Nutrients 2016, 8(12), 755; https://doi.org/10.3390/nu8120755 - 25 Nov 2016
Cited by 15
Abstract
Background: “Sleep-low” consists of a sequential periodization of carbohydrate (CHO) availability—low glycogen recovery after “train high” glycogen-depleting interval training, followed by an overnight-fast and light intensity training (“train low”) the following day. This strategy leads to an upregulation of several exercise-responsive signaling proteins, [...] Read more.
Background: “Sleep-low” consists of a sequential periodization of carbohydrate (CHO) availability—low glycogen recovery after “train high” glycogen-depleting interval training, followed by an overnight-fast and light intensity training (“train low”) the following day. This strategy leads to an upregulation of several exercise-responsive signaling proteins, but the chronic effect on performance has received less attention. We investigated the effects of short-term exposure to this strategy on endurance performance. Methods: Following training familiarization, 11 trained cyclists were divided into two groups for a one-week intervention—one group implemented three cycles of periodized CHO intake to achieve the sleep-low strategy over six training sessions (SL, CHO intake: 6 g·kg−1·day−1), whereas the control group consumed an even distribution of CHO over the day (CON). Tests were a 2 h submaximal ride and a 20 km time trial. Results: SL improved their performance (mean: +3.2%; p < 0.05) compared to CON. The improvement was associated with a change in pacing strategy with higher power output during the second part of the test. No change in substrate utilization was observed after the training period for either group. Conclusion: Implementing the “sleep-low” strategy for one week improved performance by the same magnitude previously seen in a three-week intervention, without any significant changes in selected markers of metabolism. Full article
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Open AccessArticle
Probiotic Supplements Beneficially Affect Tryptophan–Kynurenine Metabolism and Reduce the Incidence of Upper Respiratory Tract Infections in Trained Athletes: A Randomized, Double-Blinded, Placebo-Controlled Trial
Nutrients 2016, 8(11), 752; https://doi.org/10.3390/nu8110752 - 23 Nov 2016
Cited by 15
Abstract
Background: Prolonged intense exercise has been associated with transient suppression of immune function and an increased risk of infections. In this context, the catabolism of amino acid tryptophan via kynurenine may play an important role. The present study examined the effect of a [...] Read more.
Background: Prolonged intense exercise has been associated with transient suppression of immune function and an increased risk of infections. In this context, the catabolism of amino acid tryptophan via kynurenine may play an important role. The present study examined the effect of a probiotic supplement on the incidence of upper respiratory tract infections (URTI) and the metabolism of aromatic amino acids after exhaustive aerobic exercise in trained athletes during three months of winter training. Methods: Thirty-three highly trained individuals were randomly assigned to probiotic (PRO, n = 17) or placebo (PLA, n = 16) groups using double blind procedures, receiving either 1 × 1010 colony forming units (CFU) of a multi-species probiotic (Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Enterococcus faecium W54, Lactobacillus acidophilus W22, Lactobacillus brevis W63, and Lactococcus lactis W58) or placebo once per day for 12 weeks. The serum concentrations of tryptophan, phenylalanine and their primary catabolites kynurenine and tyrosine, as well as the concentration of the immune activation marker neopterin were determined at baseline and after 12 weeks, both at rest and immediately after exercise. Participants completed a daily diary to identify any infectious symptoms. Results: After 12 weeks of treatment, post-exercise tryptophan levels were lowered by 11% (a significant change) in the PLA group compared to the concentrations measured before the intervention (p = 0.02), but remained unchanged in the PRO group. The ratio of subjects taking the placebo who experienced one or more URTI symptoms was increased 2.2-fold compared to those on probiotics (PLA 0.79, PRO 0.35; p = 0.02). Conclusion: Data indicate reduced exercise-induced tryptophan degradation rates in the PRO group. Daily supplementation with probiotics limited exercise-induced drops in tryptophan levels and reduced the incidence of URTI, however, did not benefit athletic performance. Full article
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Open AccessArticle
An Exploratory Investigation of Endotoxin Levels in Novice Long Distance Triathletes, and the Effects of a Multi-Strain Probiotic/Prebiotic, Antioxidant Intervention
Nutrients 2016, 8(11), 733; https://doi.org/10.3390/nu8110733 - 17 Nov 2016
Cited by 10
Abstract
Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 [...] Read more.
Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females) were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB4ANTI; 30 billion CFU·day−1 containing 10 billion CFU·day−1 Lactobacillus acidophilus CUL-60 (NCIMB 30157), 10 billion CFU·day−1 Lactobacillus acidophillus CUL-21 (NCIMB 30156), 9.5 billion CFU·day−1 Bifidobacterium bifidum CUL-20 (NCIMB 30172) and 0.5 billion CFU·day−1 Bifidobacterium animalis subspecies lactis CUL-34 (NCIMB 30153)/55.8 mg·day−1 fructooligosaccharides/ 400 mg·day−1 α-lipoic acid, 600 mg·day−1 N-acetyl-carnitine); matched pro/prebiotic (LAB4) or placebo (PL) for 12 weeks preceding a long-distance triathlon. Plasma endotoxin units (via Limulus amebocyte lysate chromogenic quantification) and GI permeability (via 5 h urinary lactulose (L): mannitol (M) recovery) were assessed at baseline, pre-race and six days post-race. Endotoxin unit levels were not significantly different between groups at baseline (LAB4ANTI: 8.20 ± 1.60 pg·mL−1; LAB4: 8.92 ± 1.20 pg·mL−1; PL: 9.72 ± 2.42 pg·mL−1). The use of a 12-week LAB4ANTI intervention significantly reduced endotoxin units both pre-race (4.37 ± 0.51 pg·mL−1) and six days post-race (5.18 ± 0.57 pg·mL−1; p = 0.03, ηp2 = 0.35), but only six days post-race with LAB4 (5.01 ± 0.28 pg·mL−1; p = 0.01, ηp2 = 0.43). In contrast, endotoxin units remained unchanged with PL. L:M significantly increased from 0.01 ± 0.01 at baseline to 0.06 ± 0.01 with PL only (p = 0.004, ηp2 = 0.51). Mean race times (h:min:s) were not statistically different between groups despite faster times with both pro/prebiotoic groups (LAB4ANTI: 13:17:07 ± 0:34:48; LAB4: 12:47:13 ± 0:25:06; PL: 14:12:51 ± 0:29:54; p > 0.05). Combined multistrain pro/prebiotic use may reduce endotoxin unit levels, with LAB4ANTI potentially conferring an additive effect via combined GI modulation and antioxidant protection. Full article
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Open AccessArticle
Cardiorespiratory Fitness and Peak Torque Differences between Vegetarian and Omnivore Endurance Athletes: A Cross-Sectional Study
Nutrients 2016, 8(11), 726; https://doi.org/10.3390/nu8110726 - 15 Nov 2016
Cited by 5
Abstract
In spite of well-documented health benefits of vegetarian diets, less is known regarding the effects of these diets on athletic performance. In this cross-sectional study, we compared elite vegetarian and omnivore adult endurance athletes for maximal oxygen uptake (VO2 max) and strength. Twenty-seven [...] Read more.
In spite of well-documented health benefits of vegetarian diets, less is known regarding the effects of these diets on athletic performance. In this cross-sectional study, we compared elite vegetarian and omnivore adult endurance athletes for maximal oxygen uptake (VO2 max) and strength. Twenty-seven vegetarian (VEG) and 43 omnivore (OMN) athletes were evaluated using VO2 max testing on the treadmill, and strength assessment using a dynamometer to determine peak torque for leg extensions. Dietary data were assessed using detailed seven-day food logs. Although total protein intake was lower among vegetarians in comparison to omnivores, protein intake as a function of body mass did not differ by group (1.2 ± 0.3 and 1.4 ± 0.5 g/kg body mass for VEG and OMN respectively, p = 0.220). VO2 max differed for females by diet group (53.0 ± 6.9 and 47.1 ± 8.6 mL/kg/min for VEG and OMN respectively, p < 0.05) but not for males (62.6 ± 15.4 and 55.7 ± 8.4 mL/kg/min respectively). Peak torque did not differ significantly between diet groups. Results from this study indicate that vegetarian endurance athletes’ cardiorespiratory fitness was greater than that for their omnivorous counterparts, but that peak torque did not differ between diet groups. These data suggest that vegetarian diets do not compromise performance outcomes and may facilitate aerobic capacity in athletes. Full article
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Open AccessArticle
Investigating the Cellular and Metabolic Responses of World-Class Canoeists Training: A Sportomics Approach
Nutrients 2016, 8(11), 719; https://doi.org/10.3390/nu8110719 - 11 Nov 2016
Abstract
(1) Background: We have been using the Sportomics approach to evaluate biochemical and hematological changes in response to exercise. The aim of this study was to evaluate the metabolic and hematologic responses of world-class canoeists during a training session; (2) Methods: Blood samples [...] Read more.
(1) Background: We have been using the Sportomics approach to evaluate biochemical and hematological changes in response to exercise. The aim of this study was to evaluate the metabolic and hematologic responses of world-class canoeists during a training session; (2) Methods: Blood samples were taken at different points and analyzed for their hematological properties, activities of selected enzymes, hormones, and metabolites; (3) Results: Muscle stress biomarkers were elevated in response to exercise which correlated with modifications in the profile of white blood cells, where a leukocyte rise was observed after the canoe session. These results were accompanied by an increase in other exercise intensity parameters such as lactatemia and ammonemia. Adrenocorticotropic hormone and cortisol increased during the exercise sessions. The acute rise in both erythrocytes and white blood profile were probably due to muscle cell damage, rather than hepatocyte integrity impairment; (4) Conclusion: The cellular and metabolic responses found here, together with effective nutrition support, are crucial to understanding the effects of exercise in order to assist in the creation of new training and recovery planning. Also we show that Sportomics is a primal tool for training management and performance improvement, as well as to the understanding of metabolic response to exercise. Full article
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Open AccessArticle
The Effect of a 20 km Run on Appetite Regulation in Long Distance Runners
Nutrients 2016, 8(11), 672; https://doi.org/10.3390/nu8110672 - 26 Oct 2016
Cited by 7
Abstract
The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run [...] Read more.
The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run (EX) or a control trial with an identical period of rest (CON). Blood samples were collected to determine plasma acylated ghrelin, peptide YY3-36 (PYY3-36) and other hormonal and metabolite concentrations. Energy intake during a buffet test meal was also measured 30 min after the exercise or rest periods. Although plasma acylated ghrelin concentrations were significantly decreased after the 20 km run (p < 0.05), plasma PYY3-36 did not change significantly following exercise. Absolute energy intake during the buffet test meal in EX (1325 ± 55 kcal) was significantly lower than that in CON (1529 ± 55 kcal), and there was a relatively large degree of individual variability for exercise-induced changes in energy intake (−40.2% to 12.8%). However, exercise-induced changes in energy intake were not associated with plasma acylated ghrelin or PYY3-36 responses. The results demonstrated that a 20 km run significantly decreased plasma acylated ghrelin concentrations and absolute energy intake among well-trained long distance runners. Full article
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Open AccessArticle
Time of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance
Nutrients 2016, 8(10), 639; https://doi.org/10.3390/nu8100639 - 14 Oct 2016
Cited by 11
Abstract
This project was designed to assess the effects of time of day and training status on the benefits of caffeine supplementation for cycling performance. Twenty male subjects (Age, 25 years; Peak oxygen consumption, 57 mL·kg−1·min−1) were divided into tertiles [...] Read more.
This project was designed to assess the effects of time of day and training status on the benefits of caffeine supplementation for cycling performance. Twenty male subjects (Age, 25 years; Peak oxygen consumption, 57 mL·kg−1·min−1) were divided into tertiles based on training levels, with top and bottom tertiles designated as ‘trained’ (n = 7) and ‘untrained’ (n = 7). Subjects completed two familiarization trials and four experimental trials consisting of a computer-simulated 3-km cycling time trial (TT). The trials were performed in randomized order for each combination of time of day (morning and evening) and treatment (6mg/kg of caffeine or placebo). Magnitude-based inferences were used to evaluate all treatment effects. For all subjects, caffeine enhanced TT performance in the morning (2.3% ± 1.7%, ‘very likely’) and evening (1.4% ± 1.1%, ‘likely’). Both untrained and trained subjects improved performance with caffeine supplementation in the morning (5.5% ± 4.3%, ‘likely’; 1.0% ± 1.7%, ‘likely’, respectively), but only untrained subjects rode faster in the evening (2.9% ± 2.6%, ‘likely’). Altogether, our observations indicate that trained athletes are more likely to derive ergogenic effects from caffeine in the morning than the evening. Further, untrained individuals appear to receive larger gains from caffeine in the evening than their trained counterparts. Full article
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Open AccessArticle
Dietary Intake of Athletes Seeking Nutrition Advice at a Major International Competition
Nutrients 2016, 8(10), 638; https://doi.org/10.3390/nu8100638 - 14 Oct 2016
Cited by 10
Abstract
International travel and short-term residence overseas is now a common feature of an elite athlete’s competition schedule, however, food choice away from home may be challenging and potentially impact on performance. Guidelines for dietary intake specific to competition exist for athletes, however, there [...] Read more.
International travel and short-term residence overseas is now a common feature of an elite athlete’s competition schedule, however, food choice away from home may be challenging and potentially impact on performance. Guidelines for dietary intake specific to competition exist for athletes, however, there is little evidence available to ascertain if athletes meet these recommendations during competition periods, particularly when food is provided in-house. During the Delhi 2010 Commonwealth Games, dietitians based in the dining hall recorded 24 h dietary recalls with all athletes who visited the nutrition kiosk. Analysis of dietary intake was conducted with FoodWorks (Xyris Pty Ltd., Brisbane, Australia). Overall, athletes reported consuming a median total daily energy intake of 8674 kJ (range 2384–18,009 kJ), with carbohydrate within the range of 1.0–9.0 g per kg of bodyweight (g/kg) (median = 3.8) and contributing to 50% total energy (TE) (range 14%–79%). Protein and fat intake ranged from 0.3–4.0 g/kg (median = 1.7) to 10–138 g (median = 67 g), and contributed to 21% TE (range 8%–48%) and 24% TE (range 8%–44%), respectively. Athletes reported consuming between 4 and 29 different food items (median = 15) in the previous 24 h period, with predominately discretionary, grains/cereals, meats, poultry, fish, eggs, and meat alternative items. This suggests that dairy, fruit, and vegetable intake may be suboptimal and intake of the micronutrients iron, zinc, calcium, and vitamins A and C may be of concern for a number of athletes. Full article
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Open AccessArticle
Effect of 12-Week Vitamin D Supplementation on 25[OH]D Status and Performance in Athletes with a Spinal Cord Injury
Nutrients 2016, 8(10), 586; https://doi.org/10.3390/nu8100586 - 22 Sep 2016
Cited by 10
Abstract
(1) Background: studies with able-bodied athletes showed that performance might possibly be influenced by vitamin D status. Vitamin D seems to have a direct impact on neuromuscular function by docking on vitamin D receptors in the muscle tissue. Additionally, a high prevalence of [...] Read more.
(1) Background: studies with able-bodied athletes showed that performance might possibly be influenced by vitamin D status. Vitamin D seems to have a direct impact on neuromuscular function by docking on vitamin D receptors in the muscle tissue. Additionally, a high prevalence of vitamin D deficiency was shown not only in infants and in the elderly but also in healthy adults and spinal cord injured individuals. Therefore, the aim of our study was to investigate whether a vitamin D dose of 6000 IU daily over 12 weeks would be sufficient to increase vitamin D status in indoor wheelchair athletes to a normal or optimal vitamin D level and whether vitamin D deficiency is associated with an impairment in muscle performance in these individuals; (2) Methods: vitamin D status was assessed in indoor elite wheelchair athletes in order to have a baseline measurement. If vitamin D status was below 75 nmol/L, athletes were supplemented with 6000 IU of vitamin D daily over 12 weeks. A vitamin D status over 75 nmol/L was supplemented with a placebo supplement. Vitamin D status, as well as a Wingate test and an isokinetic dynamometer test, were performed at baseline and after six and 12 weeks; (3) Results: 20 indoor elite wheelchair athletes participated in this double-blind study. All of these athletes showed an insufficient vitamin D status at baseline and were, therefore, supplemented with vitamin D. All athletes increased vitamin D status significantly over 12 weeks and reached an optimal level. Wingate performance was not significantly increased. Isokinetic dynamometer strength was significantly increased but only in the non-dominant arm in isometric and concentric elbow flexion; (4) Conclusion: a dose of 6000 IU of vitamin D daily over a duration of 12 weeks seems to be sufficient to increase vitamin D status to an optimal level in indoor wheelchair athletes. It remains unclear, whether upper body performance or muscle strength and vitamin D status are associated with each other. Full article
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Open AccessArticle
Carbohydrate Mouth Rinsing Enhances High Intensity Time Trial Performance Following Prolonged Cycling
Nutrients 2016, 8(9), 576; https://doi.org/10.3390/nu8090576 - 20 Sep 2016
Cited by 10
Abstract
There is good evidence that mouth rinsing with carbohydrate (CHO) solutions can enhance endurance performance (≥30 min). The impact of a CHO mouth rinse on sprint performance has been less consistent, suggesting that CHO may confer benefits in conditions of ‘metabolic strain’. To [...] Read more.
There is good evidence that mouth rinsing with carbohydrate (CHO) solutions can enhance endurance performance (≥30 min). The impact of a CHO mouth rinse on sprint performance has been less consistent, suggesting that CHO may confer benefits in conditions of ‘metabolic strain’. To test this hypothesis, the current study examined the impact of late-exercise mouth rinsing on sprint performance. Secondly, we investigated the effects of a protein mouth rinse (PRO) on performance. Eight trained male cyclists participated in three trials consisting of 120 min of constant-load cycling (55% Wmax) followed by a 30 km computer-simulated time trial, during which only water was provided. Following 15 min of muscle function assessment, 10 min of constant-load cycling (3 min at 35% Wmax, 7 min at 55% Wmax) was performed. This was immediately followed by a 2 km time trial. Subjects rinsed with 25 mL of CHO, PRO, or placebo (PLA) at min 5:00 and 14:30 of the 15 min muscle function phase, and min 8:00 of the 10-min constant-load cycling. Magnitude-based inferential statistics were used to analyze the effects of the mouth rinse on 2-km time trial performance and the following physiological parameters: Maximum Voluntary Contract (MVC), Rating of Perceived Exertion (RPE), Heart Rate (HR), and blood glucose levels. The primary finding was that CHO ‘likely’ enhanced performance vs. PLA (3.8%), whereas differences between PRO and PLA were unclear (0.4%). These data demonstrate that late-race performance is enhanced by a CHO rinse, but not PRO, under challenging metabolic conditions. More data should be acquired before this strategy is recommended for the later stages of cycling competition under more practical conditions, such as when carbohydrates are supplemented throughout the preceding minutes/hours of exercise. Full article
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Supplemental Protein during Heavy Cycling Training and Recovery Impacts Skeletal Muscle and Heart Rate Responses but Not Performance
Nutrients 2016, 8(9), 550; https://doi.org/10.3390/nu8090550 - 07 Sep 2016
Cited by 5
Abstract
The effects of protein supplementation on cycling performance, skeletal muscle function, and heart rate responses to exercise were examined following intensified (ICT) and reduced-volume training (RVT). Seven cyclists performed consecutive periods of normal training (NT), ICT (10 days; average training duration 220% of [...] Read more.
The effects of protein supplementation on cycling performance, skeletal muscle function, and heart rate responses to exercise were examined following intensified (ICT) and reduced-volume training (RVT). Seven cyclists performed consecutive periods of normal training (NT), ICT (10 days; average training duration 220% of NT), and RVT (10 days; training duration 66% of NT). In a crossover design, subjects consumed supplemental carbohydrate (CHO) or an equal amount of carbohydrate with added protein (CP) during and following each exercise session (CP = +0.94 g/kg/day protein during ICT; +0.39 g/kg/day during RVT). A 30-kilometer time trial performance (following 120 min at 50% Wmax) was modestly impaired following ICT (+2.4 ± 6.4% versus NT) and returned to baseline levels following RVT (−0.7 ± 4.5% versus NT), with similar responses between CHO and CP. Skeletal muscle torque at 120 deg/s benefited from CP, compared to CHO, following ICT. However, this effect was no longer present at RVT. Following ICT, muscle fiber cross-sectional area was increased with CP, while there were no clear changes with CHO. Reductions in constant-load heart rates (at 50% Wmax) following RVT were likely greater with CP than CHO (−9 ± 9 bpm). Overall it appears that CP supplementation impacted skeletal muscle and heart rate responses during a period of heavy training and recovery, but this did not result in meaningful changes in time trial performance. Full article
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The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients
Nutrients 2016, 8(9), 548; https://doi.org/10.3390/nu8090548 - 07 Sep 2016
Cited by 5
Abstract
Objectives: The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A [...] Read more.
Objectives: The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A secondary aim investigated applying different physical activity level (PAL) coefficients to determine total energy expenditure (TEE) in order to more effectively evaluate the adequacy of energy intakes. Design: Cross-sectional. Methods: Anthropometrics and dietary intakes were assessed in 25 competitive adolescent male rugby union players (14 to 18 years old). Diet was assessed using the validated Australian Eating Survey (AES) food frequency questionnaire and diet quality was assessed through the Australian Recommended Food Score. Results: The median dietary intakes of participants met national recommendations for percent energy (% E) from carbohydrate, protein and total fat, but not carbohydrate intake when evaluated as g/day as proposed in SDA guidelines. Median intakes of fibre and micronutrients including calcium and iron also met national recommendations. Overall diet quality was classified as ‘good’ with a median diet quality score of 34 (out of a possible 73); however, there was a lack of variety within key food groups including carbohydrates and proteins. Non-core food consumption exceeded recommended levels at 38% of the daily total energy intake, with substantial contributions from takeaway foods and sweetened beverages. A PAL coefficient of 1.2–1.4 was found to best balance the energy intakes of these players in their pre-season. Conclusions: Adolescent rugby players met the percent energy recommendations for macronutrients and attained an overall ‘good’ diet quality score. However, it was identified that when compared to specific recommendations for athletes, carbohydrate intakes were below recommendations and these players in their pre-season reported high consumption of non-core foods, particularly sugar sweetened drinks and low intakes of vegetables. Full article
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Open AccessArticle
Effect of a Nutritional Intervention in Athlete’s Body Composition, Eating Behaviour and Nutritional Knowledge: A Comparison between Adults and Adolescents
Nutrients 2016, 8(9), 535; https://doi.org/10.3390/nu8090535 - 07 Sep 2016
Cited by 10
Abstract
The objective of the present study is to evaluate and compare the effect of a nutritional intervention between adolescent and adult. In a before and after quasi-experimental clinical study, 32 athletes (21 adults, age range 20–32 years; 11 adolescents, age range: 12–19 years) [...] Read more.
The objective of the present study is to evaluate and compare the effect of a nutritional intervention between adolescent and adult. In a before and after quasi-experimental clinical study, 32 athletes (21 adults, age range 20–32 years; 11 adolescents, age range: 12–19 years) participated in a nutritional counselling consisting of four consultations separated by an interval of 45 to 60 days. The athlete’s eating behaviour, body composition and nutrition knowledge were evaluated at the beginning and at the end of the protocol. Both groups increased lean body mass and nutritional knowledge. Adolescents increased their mid-arm muscle circumference and improved meal frequency, and daily water intake. Athletes of both groups improved their ingestion of vegetables and fruits and decreased the ingestion of sweets and oils. Adolescents showed a higher prevalence of individuals that remained within or approached to the recommendations of sweets. This is the first study to evaluate and compare the effect of a nutritional intervention between adolescent and adult athletes body composition, eating behaviour and nutritional knowledge. The nutritional counselling has been effective in promoting beneficial changes on the athlete’s eating behaviour, nutritional knowledge and body composition, however, some healthy changes were only experienced by adolescents, especially in the frequency of meals and the intake of sweets. Full article
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Effects of a Short-Term High-Nitrate Diet on Exercise Performance
Nutrients 2016, 8(9), 534; https://doi.org/10.3390/nu8090534 - 31 Aug 2016
Cited by 16
Abstract
It has been reported that nitrate supplementation can improve exercise performance. Most of the studies have used either beetroot juice or sodium nitrate as a supplement; there is lack of data on the potential ergogenic benefits of an increased dietary nitrate intake from [...] Read more.
It has been reported that nitrate supplementation can improve exercise performance. Most of the studies have used either beetroot juice or sodium nitrate as a supplement; there is lack of data on the potential ergogenic benefits of an increased dietary nitrate intake from a diet based on fruits and vegetables. Our aim was to assess whether a high-nitrate diet increases nitric oxide bioavailability and to evaluate the effects of this nutritional intervention on exercise performance. Seven healthy male subjects participated in a randomized cross-over study. They were tested before and after 6 days of a high (HND) or control (CD) nitrate diet (~8.2 mmol∙day−1 or ~2.9 mmol∙day−1, respectively). Plasma nitrate and nitrite concentrations were significantly higher in HND (127 ± 64 µM and 350 ± 120 nM, respectively) compared to CD (23 ± 10 µM and 240 ± 100 nM, respectively). In HND (vs. CD) were observed: (a) a significant reduction of oxygen consumption during moderate-intensity constant work-rate cycling exercise (1.178 ± 0.141 vs. 1.269 ± 0.136 L·min−1); (b) a significantly higher total muscle work during fatiguing, intermittent sub-maximal isometric knee extension (357.3 ± 176.1 vs. 253.6 ± 149.0 Nm·s·kg−1); (c) an improved performance in Repeated Sprint Ability test. These findings suggest that a high-nitrate diet could be a feasible and effective strategy to improve exercise performance. Full article
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Dietary Intakes and Supplement Use in Pre-Adolescent and Adolescent Canadian Athletes
Nutrients 2016, 8(9), 526; https://doi.org/10.3390/nu8090526 - 26 Aug 2016
Cited by 12
Abstract
Young athletes experience numerous dietary challenges including growth, training/competition, unhealthy food environments, and travel. The objective was to determine nutrient intakes and supplement use in pre-adolescent and adolescent Canadian athletes. Athletes (n = 187) aged 11–18 years completed an on-line 24-h food [...] Read more.
Young athletes experience numerous dietary challenges including growth, training/competition, unhealthy food environments, and travel. The objective was to determine nutrient intakes and supplement use in pre-adolescent and adolescent Canadian athletes. Athletes (n = 187) aged 11–18 years completed an on-line 24-h food recall and dietary supplement questionnaire. Median energy intake (interquartile range) varied from 2159 kcal/day (1717–2437) in 11–13 years old females to 2905 kcal/day (2291–3483) in 14–18 years old males. Carbohydrate and protein intakes were 8.1 (6.1–10.5); 2.4 (1.6–3.4) in males 11–13 years, 5.7 (4.5–7.9); 2.0 (1.4–2.6) in females 11–13 years, 5.3 (4.3–7.4); 2.0 (1.5–2.4) in males 14–18 y and 4.9 (4.4–6.2); 1.7 (1.3–2.0) in females 14–18 years g/kg of body weight respectively. Median vitamin D intakes were below the recommended dietary allowance (RDA) and potassium was below the adequate intake (AI) for all athlete groups. Females 14–18 years had intakes below the RDA for iron 91% (72–112), folate 89% (61–114) and calcium 84% (48–106). Multivitamin-multiminerals, vitamin C, vitamin D, vitamin-enriched water, protein powder, sport foods, fatty acids, probiotics, and plant extracts were popular supplements. Canadian pre-adolescent and adolescent athletes could improve their dietary intakes by focusing on food sources of calcium, vitamin D, potassium, iron, and folate. With the exceptions of vitamin D and carbohydrates during long exercise sessions, supplementation is generally unnecessary. Full article
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Open AccessArticle
Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity
Nutrients 2016, 8(8), 518; https://doi.org/10.3390/nu8080518 - 22 Aug 2016
Cited by 11
Abstract
Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and [...] Read more.
Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune changes. Trained cyclists (n = 20, 48 ± 2 years) participated in a randomized, placebo controlled, crossover study. Subjects completed two 75 km cycling time trials after either 2 weeks ingestion of 980 mL/day WM puree or no treatment. Subjects drank either WM puree containing 0.2 gm/kg carbohydrate or a 6% carbohydrate beverage every 15 min during the time trials. Blood samples were taken pre-study and pre-, post-, 1 h post-exercise. WM ingestion versus no treatment for 2-weeks increased plasma l-citrulline and l-arginine concentrations (p < 0.0125). Exercise performance did not differ between WM puree or carbohydrate beverage trials (p > 0.05), however, the rating of perceived exertion was greater during the WM trial (p > 0.05). WM puree versus carbohydrate beverage resulted in a similar pattern of increase in blood glucose, and greater increases in post-exercise plasma antioxidant capacity, l-citrulline, l-arginine, and total nitrate (all p < 0.05), but without differences in systemic markers of inflammation or innate immune function. Daily WM puree consumption fully supported the energy demands of exercise, and increased post-exercise blood levels of WM nutritional components (l-citrulline and l-arginine), antioxidant capacity, and total nitrate, but without an influence on post-exercise inflammation and changes in innate immune function. Full article
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Effects of Beetroot Juice on Recovery of Muscle Function and Performance between Bouts of Repeated Sprint Exercise
Nutrients 2016, 8(8), 506; https://doi.org/10.3390/nu8080506 - 18 Aug 2016
Cited by 17
Abstract
This study examined the effects of beetroot juice (BTJ) on recovery between two repeated-sprint tests. In an independent groups design, 20 male, team-sports players were randomized to receive either BTJ or a placebo (PLA) (2 × 250 mL) for 3 days after an [...] Read more.
This study examined the effects of beetroot juice (BTJ) on recovery between two repeated-sprint tests. In an independent groups design, 20 male, team-sports players were randomized to receive either BTJ or a placebo (PLA) (2 × 250 mL) for 3 days after an initial repeated sprint test (20 × 30 m; RST1) and after a second repeated sprint test (RST2), performed 72 h later. Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), reactive strength index (RI), pressure-pain threshold (PPT), creatine kinase (CK), C-reactive protein (hs-CRP), protein carbonyls (PC), lipid hydroperoxides (LOOH) and the ascorbyl free radical (A•−) were measured before, after, and at set times between RST1 and RST2. CMJ and RI recovered quicker in BTJ compared to PLA after RST1: at 72 h post, CMJ and RI were 7.6% and 13.8% higher in BTJ vs. PLA, respectively (p < 0.05). PPT was 10.4% higher in BTJ compared to PLA 24 h post RST2 (p = 0.012) but similar at other time points. No group differences were detected for mean and fastest sprint time or fatigue index. MIVC, or the biochemical markers measured (p > 0.05). BTJ reduced the decrement in CMJ and RI following and RST but had no effect on sprint performance or oxidative stress. Full article
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Vitamin D Status and Supplementation Practices in Elite Irish Athletes: An Update from 2010/2011
Nutrients 2016, 8(8), 485; https://doi.org/10.3390/nu8080485 - 09 Aug 2016
Cited by 2
Abstract
Vitamin D deficiency is a global health concern that is prevalent in Ireland. The vitamin D status of elite Irish athletes following implementation of a revised supplementation policy in 2010/2011 has not been explored to date. This study aimed to assess the vitamin [...] Read more.
Vitamin D deficiency is a global health concern that is prevalent in Ireland. The vitamin D status of elite Irish athletes following implementation of a revised supplementation policy in 2010/2011 has not been explored to date. This study aimed to assess the vitamin D status of elite Irish athletes participating in high-profile sports and establish if equatorial travel, supplementation and/or sunbed use predict vitamin D status. Across Ireland, blood samples (n = 92) were obtained from cricketers (n = 28), boxers (n = 21) and women’s rugby sevens players (n = 43) between November 2013 and April 2015. Total 25-hydroxyvitamin D (25(OH)D) concentrations were quantified using LC-MS/MS. Parathyroid hormone and adjusted calcium concentrations were measured by clinical biochemistry. Athletes completed a questionnaire that queried equatorial travel, supplementation and sunbed use. Vitamin D sufficiency (25(OH)D >50 nmol/L) was evident in 86% of athletes. Insufficiency (31–49 nmol/L) and deficiency (<30 nmol/L) was present in only 12% and 2% of athletes respectively. On average, athletes from all sport disciplines were vitamin D sufficient and 25% reported vitamin D supplementation which was a significant positive predictor of vitamin D status, (OR 4.31; 95% CI 1.18–15.75; p = 0.027). Equatorial travel and sun bed use were reported in 47% and 16% of athletes respectively however these factors did not predict vitamin D status (both p > 0.05). Although different cohorts were assessed, the overall prevalence of vitamin D insufficiency/deficiency was 55% in 2010/2011 compared with only 14% in 2013/2015. Targeted supplementation is highly effective in optimising vitamin D status, negating the need for blanket-supplementation in elite cohorts. Full article
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The Effects of Montmorency Tart Cherry Concentrate Supplementation on Recovery Following Prolonged, Intermittent Exercise
Nutrients 2016, 8(7), 441; https://doi.org/10.3390/nu8070441 - 22 Jul 2016
Cited by 23
Abstract
This study investigated Montmorency tart cherry concentrate (MC) supplementation on markers of recovery following prolonged, intermittent sprint activity. Sixteen semi-professional, male soccer players, who had dietary restrictions imposed for the duration of the study, were divided into two equal groups and consumed either [...] Read more.
This study investigated Montmorency tart cherry concentrate (MC) supplementation on markers of recovery following prolonged, intermittent sprint activity. Sixteen semi-professional, male soccer players, who had dietary restrictions imposed for the duration of the study, were divided into two equal groups and consumed either MC or placebo (PLA) supplementation for eight consecutive days (30 mL twice per day). On day 5, participants completed an adapted version of the Loughborough Intermittent Shuttle Test (LISTADAPT). Maximal voluntary isometric contraction (MVIC), 20 m Sprint, counter movement jump (CMJ), agility and muscle soreness (DOMS) were assessed at baseline, and 24, 48 and 72 h post-exercise. Measures of inflammation (IL-1-β, IL-6, IL-8, TNF-α, hsCRP), muscle damage (CK) and oxidative stress (LOOH) were analysed at baseline and 1, 3, 5, 24, 48 and 72 h post-exercise. Performance indices (MVIC, CMJ and agility) recovered faster and muscle soreness (DOMS) ratings were lower in the MC group (p < 0.05). Additionally, the acute inflammatory response (IL-6) was attenuated in the MC group. There were no effects for LOOH and CK. These findings suggest MC is efficacious in accelerating recovery following prolonged, repeat sprint activity, such as soccer and rugby, and lends further evidence that polyphenol-rich foods like MC are effective in accelerating recovery following various types of strenuous exercise. Full article
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Improvements in Cycling but Not Handcycling 10 km Time Trial Performance in Habitual Caffeine Users
Nutrients 2016, 8(7), 393; https://doi.org/10.3390/nu8070393 - 25 Jun 2016
Cited by 12
Abstract
Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) [...] Read more.
Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake ( V · peak) 42.9 (7.3)/27.6 (5.1) mL∙kg∙min−1, 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific V · peak (preload) followed by a 10 km TT following the ingestion of 4 mg∙kg−1 caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p < 0.007) and was evident 5 min post-TT during cycling (11.2 ± 2.6 and 8.8 ± 3.2 mmol/L; p = 0.001) and handcycling (10.6 ± 2.5 and 9.2 ± 2.9 mmol/L; p = 0.006). Lower overall ratings of perceived exertion (RPE) were seen following CAF during the preload (p < 0.05) but not post-TT. Lower peripheral RPE were reported at 20 min during cycling and at 30 min during handcycling, and lower central RPE was seen at 30 min during cycling (p < 0.05). Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants’ training status. Full article
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Slow-Absorbing Modified Starch before and during Prolonged Cycling Increases Fat Oxidation and Gastrointestinal Distress without Changing Performance
Nutrients 2016, 8(7), 392; https://doi.org/10.3390/nu8070392 - 25 Jun 2016
Cited by 6
Abstract
While prior research reported altered fuel utilization stemming from pre-exercise modified starch ingestion, the practical value of this starch for endurance athletes who consume carbohydrates both before and during exercise is yet to be examined. The purpose of this study was to determine [...] Read more.
While prior research reported altered fuel utilization stemming from pre-exercise modified starch ingestion, the practical value of this starch for endurance athletes who consume carbohydrates both before and during exercise is yet to be examined. The purpose of this study was to determine the effects of ingesting a hydrothermally-modified starch supplement (HMS) before and during cycling on performance, metabolism, and gastrointestinal comfort. In a crossover design, 10 male cyclists underwent three nutritional interventions: (1) a commercially available sucrose/glucose supplement (G) 30 min before (60 g carbohydrate) and every 15 min during exercise (60 g∙h−1); (2) HMS consumed at the same time points before and during exercise in isocaloric amounts to G (Iso HMS); and (3) HMS 30 min before (60 g carbohydrate) and every 60 min during exercise (30 g·h−1; Low HMS). The exercise protocol (~3 h) consisted of 1 h at 50% Wmax, 8 × 2-min intervals at 80% Wmax, and 10 maximal sprints. There were no differences in sprint performance with Iso HMS vs. G, while both G and Iso HMS likely resulted in small performance enhancements (5.0%; 90% confidence interval = ±5.3% and 4.4%; ±3.2%, respectively) relative to Low HMS. Iso HMS and Low HMS enhanced fat oxidation (31.6%; ±20.1%; very likely (Iso); 20.9%; ±16.1%; likely (Low), and reduced carbohydrate oxidation (−19.2%; ±7.6%; most likely; −22.1%; ±12.9%; very likely) during exercise relative to G. However, nausea was increased during repeated sprints with ingestion of Iso HMS (17 scale units; ±18; likely) and Low HMS (18; ±14; likely) vs. G. Covariate analysis revealed that gastrointestinal distress was associated with reductions in performance with Low HMS vs. G (likely), but this relationship was unclear with Iso HMS vs. G. In conclusion, pre- and during-exercise ingestion of HMS increases fat oxidation relative to G. However, changes do not translate to performance improvements, possibly owing to HMS-associated increases in gastrointestinal distress, which is not attenuated by reducing the intake rate of HMS during exercise. Full article
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Open AccessArticle
Substrate Utilization and Cycling Performance Following Palatinose™ Ingestion: A Randomized, Double-Blind, Controlled Trial
Nutrients 2016, 8(7), 390; https://doi.org/10.3390/nu8070390 - 23 Jun 2016
Cited by 7
Abstract
(1) Objective: To compare the effects of isomaltulose (Palatinose™, PSE) vs. maltodextrin (MDX) ingestion on substrate utilization during endurance exercise and subsequent time trial performance; (2) Methods: 20 male athletes performed two experimental trials with ingestion of either 75 g PSE or MDX [...] Read more.
(1) Objective: To compare the effects of isomaltulose (Palatinose™, PSE) vs. maltodextrin (MDX) ingestion on substrate utilization during endurance exercise and subsequent time trial performance; (2) Methods: 20 male athletes performed two experimental trials with ingestion of either 75 g PSE or MDX 45 min before the start of exercise. The exercise protocol consisted of 90 min cycling (60% VO2max) followed by a time trial; (3) Results: Time trial finishing time (−2.7%, 90% CI: ±3.0%, 89% likely beneficial; p = 0.147) and power output during the final 5 min (+4.6%, 90% CI: ±4.0%, 93% likely beneficial; p = 0.053) were improved with PSE compared with MDX. The blood glucose profile differed between trials (p = 0.013) with PSE resulting in lower glycemia during rest (95%–99% likelihood) and higher blood glucose concentrations during exercise (63%–86% likelihood). In comparison to MDX, fat oxidation was higher (88%–99% likelihood; p = 0.005) and carbohydrate oxidation was lower following PSE intake (85%–96% likelihood; p = 0.002). (4) Conclusion: PSE maintained a more stable blood glucose profile and higher fat oxidation during exercise which resulted in improved cycling performance compared with MDX. These results could be explained by the slower availability and the low-glycemic properties of Palatinose™ allowing a greater reliance on fat oxidation and sparing of glycogen during the initial endurance exercise. Full article
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25(OH)D Status of Elite Athletes with Spinal Cord Injury Relative to Lifestyle Factors
Nutrients 2016, 8(6), 374; https://doi.org/10.3390/nu8060374 - 17 Jun 2016
Cited by 12
Abstract
Background: Due to the potential negative impact of low Vitamin D status on performance-related factors and the higher risk of low Vitamin D status in Spinal Cord Injury (SCI) population, research is warranted to determine whether elite athletes with SCI have sufficient 25(OH)D [...] Read more.
Background: Due to the potential negative impact of low Vitamin D status on performance-related factors and the higher risk of low Vitamin D status in Spinal Cord Injury (SCI) population, research is warranted to determine whether elite athletes with SCI have sufficient 25(OH)D levels. The purposes of this study were to examine: (1) the seasonal proportion of vitamin D insufficiency among elite athletes with SCI; and (2) to determine whether lifestyle factors, SCI lesion level, and muscle performance/function are related to vitamin D status in athletes with SCI. Methods: Thirty-nine members of the Canadian Wheelchair Sports Association, and the US Olympic Committee Paralympic program from outdoor and indoor sports were recruited for this study. Dietary and lifestyle factors, and serum 25(OH)D concentrations were assessed during the autumn (October) and winter (February/March). An independent t-test was used to assess differences in 25(OH)D status among seasons, and indoor and outdoor sports in the autumn and winter, respectively. Results: Mean ± SD serum 25(OH)D concentration was 69.6 ± 19.7 nmol/L (range from 30 to 107.3 nmol/L) and 67.4 ± 25.5 nmol/L (range from 20 to 117.3 nmol/L)in the autumn and winter, respectively. In the autumn, 15.4% of participants were considered vitamin D deficient (25(OH)D < 50 nmol/L) whereas 51.3% had 25(OH)D concentrations that would be considered insufficient (<80 nmol/L). In the winter, 15.4% were deficient while 41% of all participants were considered vitamin D insufficient. Conclusion: A substantial proportion of elite athletes with SCI have insufficient (41%–51%) and deficient (15.4%) 25(OH)D status in the autumn and winter. Furthermore, a seasonal decline in vitamin D status was not observed in the current study. Full article
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Open AccessArticle
Protein-Pacing and Multi-Component Exercise Training Improves Physical Performance Outcomes in Exercise-Trained Women: The PRISE 3 Study
Nutrients 2016, 8(6), 332; https://doi.org/10.3390/nu8060332 - 01 Jun 2016
Cited by 5
Abstract
The beneficial cardiometabolic and body composition effects of combined protein-pacing (P; 5–6 meals/day at 2.0 g/kg BW/day) and multi-mode exercise (resistance, interval, stretching, endurance; RISE) training (PRISE) in obese adults has previously been established. The current study examines PRISE on physical performance (endurance, [...] Read more.
The beneficial cardiometabolic and body composition effects of combined protein-pacing (P; 5–6 meals/day at 2.0 g/kg BW/day) and multi-mode exercise (resistance, interval, stretching, endurance; RISE) training (PRISE) in obese adults has previously been established. The current study examines PRISE on physical performance (endurance, strength and power) outcomes in healthy, physically active women. Thirty exercise-trained women (>4 days exercise/week) were randomized to either PRISE (n = 15) or a control (CON, 5–6 meals/day at 1.0 g/kg BW/day; n = 15) for 12 weeks. Muscular strength (1-RM bench press, 1-RM BP) endurance (sit-ups, SUs; push-ups, PUs), power (bench throws, BTs), blood pressure (BP), augmentation index, (AIx), and abdominal fat mass were assessed at Weeks 0 (pre) and 13 (post). At baseline, no differences existed between groups. Following the 12-week intervention, PRISE had greater gains (p < 0.05) in SUs, PUs (6 ± 7 vs. 10 ± 7, 40%; 8 ± 13 vs. 14 ± 12, 43% ∆reps, respectively), BTs (11 ± 35 vs. 44 ± 34, 75% ∆watts), AIx (1 ± 9 vs. −5 ± 11, 120%), and DBP (−5 ± 9 vs. −11 ± 11, 55% ∆mmHg). These findings suggest that combined protein-pacing (P; 5–6 meals/day at 2.0 g/kg BW/day) diet and multi-component exercise (RISE) training (PRISE) enhances muscular endurance, strength, power, and cardiovascular health in exercise-trained, active women. Full article
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Open AccessArticle
Protein-Pacing from Food or Supplementation Improves Physical Performance in Overweight Men and Women: The PRISE 2 Study
Nutrients 2016, 8(5), 288; https://doi.org/10.3390/nu8050288 - 11 May 2016
Cited by 4
Abstract
We recently reported that protein-pacing (P; six meals/day @ 1.4 g/kg body weight (BW), three of which included whey protein (WP) supplementation) combined with a multi-mode fitness program consisting of resistance, interval sprint, stretching, and endurance exercise training (RISE) improves body composition in [...] Read more.
We recently reported that protein-pacing (P; six meals/day @ 1.4 g/kg body weight (BW), three of which included whey protein (WP) supplementation) combined with a multi-mode fitness program consisting of resistance, interval sprint, stretching, and endurance exercise training (RISE) improves body composition in overweight individuals. The purpose of this study was to extend these findings and determine whether protein-pacing with only food protein (FP) is comparable to WP supplementation during RISE training on physical performance outcomes in overweight/obese individuals. Thirty weight-matched volunteers were prescribed RISE training and a P diet derived from either whey protein supplementation (WP, n = 15) or food protein sources (FP, n = 15) for 16 weeks. Twenty-one participants completed the intervention (WP, n = 9; FP, n = 12). Measures of body composition and physical performance were significantly improved in both groups (p < 0.05), with no effect of protein source. Likewise, markers of cardiometabolic disease risk (e.g., LDL (low-density lipoprotein) cholesterol, glucose, insulin, adiponectin, systolic blood pressure) were significantly improved (p < 0.05) to a similar extent in both groups. These results demonstrate that both whey protein and food protein sources combined with multimodal RISE training are equally effective at improving physical performance and cardiometabolic health in obese individuals. Full article
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Review

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Open AccessReview
Pre-Sleep Protein Ingestion to Improve the Skeletal Muscle Adaptive Response to Exercise Training
Nutrients 2016, 8(12), 763; https://doi.org/10.3390/nu8120763 - 28 Nov 2016
Cited by 26
Abstract
Protein ingestion following resistance-type exercise stimulates muscle protein synthesis rates, and enhances the skeletal muscle adaptive response to prolonged resistance-type exercise training. As the adaptive response to a single bout of resistance exercise extends well beyond the first couple of hours of post-exercise [...] Read more.
Protein ingestion following resistance-type exercise stimulates muscle protein synthesis rates, and enhances the skeletal muscle adaptive response to prolonged resistance-type exercise training. As the adaptive response to a single bout of resistance exercise extends well beyond the first couple of hours of post-exercise recovery, recent studies have begun to investigate the impact of the timing and distribution of protein ingestion during more prolonged recovery periods. Recent work has shown that overnight muscle protein synthesis rates are restricted by the level of amino acid availability. Protein ingested prior to sleep is effectively digested and absorbed, and thereby stimulates muscle protein synthesis rates during overnight recovery. When applied during a prolonged period of resistance-type exercise training, protein supplementation prior to sleep can further augment gains in muscle mass and strength. Recent studies investigating the impact of pre-sleep protein ingestion suggest that at least 40 g of protein is required to display a robust increase in muscle protein synthesis rates throughout overnight sleep. Furthermore, prior exercise allows more of the pre-sleep protein-derived amino acids to be utilized for de novo muscle protein synthesis during sleep. In short, pre-sleep protein ingestion represents an effective dietary strategy to improve overnight muscle protein synthesis, thereby improving the skeletal muscle adaptive response to exercise training. Full article
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Open AccessReview
Exercise, Appetite and Weight Control: Are There Differences between Men and Women?
Nutrients 2016, 8(9), 583; https://doi.org/10.3390/nu8090583 - 21 Sep 2016
Cited by 15
Abstract
Recent years have witnessed significant research interest surrounding the interaction among exercise, appetite and energy balance, which has important implications for health. The majority of exercise and appetite regulation studies have been conducted in males. Consequently, opportunities to examine sex-based differences have been [...] Read more.
Recent years have witnessed significant research interest surrounding the interaction among exercise, appetite and energy balance, which has important implications for health. The majority of exercise and appetite regulation studies have been conducted in males. Consequently, opportunities to examine sex-based differences have been limited, but represent an interesting avenue of inquiry considering postulations that men experience greater weight loss after exercise interventions than women. This article reviews the scientific literature relating to the acute and chronic effects of exercise on appetite control in men and women. The consensus of evidence demonstrates that appetite, appetite-regulatory hormone and energy intake responses to acute exercise do not differ between the sexes, and there is little evidence indicating compensatory changes occur after acute exercise in either sex. Limited evidence suggests women respond to the initiation of exercise training with more robust compensatory alterations in appetite-regulatory hormones than men, but whether this translates to long-term differences is unknown. Current exercise training investigations do not support sex-based differences in appetite or objectively assessed energy intake, and increasing exercise energy expenditure elicits at most a partial energy intake compensation in both sexes. Future well-controlled acute and chronic exercise studies directly comparing men and women are required to expand this evidence base. Full article
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Open AccessReview
A Systematic Review of Athletes’ and Coaches’ Nutrition Knowledge and Reflections on the Quality of Current Nutrition Knowledge Measures
Nutrients 2016, 8(9), 570; https://doi.org/10.3390/nu8090570 - 16 Sep 2016
Cited by 26
Abstract
Context: Nutrition knowledge can influence dietary choices and impact on athletic performance. Valid and reliable measures are needed to assess the nutrition knowledge of athletes and coaches. Objectives: (1) To systematically review the published literature on nutrition knowledge of adult athletes and coaches [...] Read more.
Context: Nutrition knowledge can influence dietary choices and impact on athletic performance. Valid and reliable measures are needed to assess the nutrition knowledge of athletes and coaches. Objectives: (1) To systematically review the published literature on nutrition knowledge of adult athletes and coaches and (2) to assess the quality of measures used to assess nutrition knowledge. Data Sources: MEDLINE, CINAHL, SPORTDiscuss, Web of Science, and SCOPUS. Study Selection: 36 studies that provided a quantitative measure of nutrition knowledge and described the measurement tool that was used were included. Data extraction: Participant description, questionnaire description, results (mean correct and responses to individual items), study quality, and questionnaire quality. Data synthesis: All studies were of neutral quality. Tools used to measure knowledge did not consider health literacy, were outdated with regards to consensus recommendations, and lacked appropriate and adequate validation. The current status of nutrition knowledge in athletes and coaches is difficult to ascertain. Gaps in knowledge also remain unclear, but it is likely that energy density, the need for supplementation, and the role of protein are frequently misunderstood. Conclusions: Previous reports of nutrition knowledge need to be interpreted with caution. A new, universal, up-to-date, validated measure of general and sports nutrition knowledge is required to allow for assessment of nutrition knowledge. Full article
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Open AccessReview
Dietary Recommendations for Cyclists during Altitude Training
Nutrients 2016, 8(6), 377; https://doi.org/10.3390/nu8060377 - 18 Jun 2016
Cited by 13
Abstract
The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like “live high, train high” (LH-TH), “live high, train low” (LH-TL) or “intermittent hypoxic training” (IHT). Each of them combines the [...] Read more.
The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like “live high, train high” (LH-TH), “live high, train low” (LH-TL) or “intermittent hypoxic training” (IHT). Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented. Full article
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Other

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Open AccessFeature PaperConcept Paper
“Eat as If You Could Save the Planet and Win!” Sustainability Integration into Nutrition for Exercise and Sport
Nutrients 2017, 9(4), 412; https://doi.org/10.3390/nu9040412 - 21 Apr 2017
Cited by 10
Abstract
Today’s industrial food production contributes significantly to environmental degradation. Meat production accounts for the largest impact, including greenhouse gas emissions, land and water use. While food production and consumption are important aspects when addressing climate change, this article focuses predominantly on dietary change [...] Read more.
Today’s industrial food production contributes significantly to environmental degradation. Meat production accounts for the largest impact, including greenhouse gas emissions, land and water use. While food production and consumption are important aspects when addressing climate change, this article focuses predominantly on dietary change that promotes both health for planet and people with focus on athletes. Healthy, sustainable eating recommendations begin to appear in various governmental guidelines. However, there remains resistance to the suggested reductions in meat consumption. While food citizens are likely to choose what is good for them and the planet, others may not, unless healthy eating initiatives integrate creative food literacy approaches with experiential learning as a potential vehicle for change. This concept paper is organized in three sections: (1) Environmental impact of food; (2) health and sustainability connections; and (3) application in sports and exercise. For active individuals, this article focuses on the quantity of protein, highlighting meat and dairy, and quality of food, with topics such as organic production and biodiversity. Finally, the timing of when to integrate sustainability principles in sport nutrition is discussed, followed by practical applications for education and inclusion in team, institutional, and event operations. Full article
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Open AccessCase Report
Dietary Intake, Body Composition, and Menstrual Cycle Changes during Competition Preparation and Recovery in a Drug-Free Figure Competitor: A Case Study
Nutrients 2016, 8(11), 740; https://doi.org/10.3390/nu8110740 - 20 Nov 2016
Cited by 5
Abstract
Physique competitions are events in which competitors are judged on muscular appearance and symmetry. The purpose of this retrospective case study was to describe changes in dietary intake, body mass/composition, and the menstrual cycle during the 20-week competition preparation (PREP) and 20-week post [...] Read more.
Physique competitions are events in which competitors are judged on muscular appearance and symmetry. The purpose of this retrospective case study was to describe changes in dietary intake, body mass/composition, and the menstrual cycle during the 20-week competition preparation (PREP) and 20-week post competition recovery (REC) periods of a drug-free amateur female figure competitor (age = 26–27, BMI = 19.5 kg/m2). Dietary intake (via weighed food records) and body mass were assessed daily and averaged weekly. Body composition was estimated via Dual-energy X-ray absorptiometry (DXA) and 7-site skinfold measurements. Energy intake, body mass and composition, and energy availability decreased during the 20-week PREP period (changes of ~298 kcals, 5.1 kg, 6.5% body fat, and 5.4 kcal/kg fat free mass, respectively) and returned to baseline values by end of the 20-week REC period. Menstrual cycle irregularity was reported within the first month of PREP and the last menstruation was reported at week 11 of PREP. Given the potentially adverse health outcomes associated with caloric restriction, future, prospective cohort studies on the physiological response to PREP and REC are warranted in drug-free, female physique competitors. Full article
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Open AccessBrief Report
Effects of Beer, Non-Alcoholic Beer and Water Consumption before Exercise on Fluid and Electrolyte Homeostasis in Athletes
Nutrients 2016, 8(6), 345; https://doi.org/10.3390/nu8060345 - 07 Jun 2016
Cited by 2
Abstract
Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study [...] Read more.
Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the effect of beer, non-alcoholic beer and water consumption before exercise on fluid and electrolyte homeostasis. Seven male soccer players performed 45 min of treadmill running at 65% of the maximal heart rate, 45 min after ingesting 0.7 L of water (W), beer (AB) or non-alcoholic beer (NAB). Body mass, plasma Na+ and K+ concentrations and urine specific gravity (USG) were assessed before fluid consumption and after exercise. After exercise, body mass decreased (p < 0.05) in W (−1.1%), AB (−1.0%) and NAB (−1.0%). In the last minutes of exercise, plasma Na+ was reduced (p < 0.05) in W (−3.9%) and AB (−3.7%), plasma K+ was increased (p < 0.05) in AB (8.5%), and USG was reduced in W (−0.9%) and NAB (−1.0%). Collectively, these results suggest that non-alcoholic beer before exercise could help maintain electrolyte homeostasis during exercise. Alcoholic beer intake reduced plasma Na+ and increased plasma K+ during exercise, which may negatively affect health and physical performance, and finally, the consumption of water before exercise could induce decreases of Na+ in plasma during exercise. Full article
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