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16 pages, 1112 KB

Open AccessArticle

Acute 1,3-Butanediol Co-Ingestion with Carbohydrate Does Not Improve Endurance Performance in Chronically Ketogenic Male Athletes

by Matthew Carpenter, James Brouner and Owen Spendiff

Nutrients 2026, 18(14), 2388; https://doi.org/10.3390/nu18142388 - 22 Jul 2026

Abstract

Background/Objectives: Exogenous ketone supplementation has been proposed to enhance endurance performance by altering substrate metabolism and sparing muscle glycogen. Prolonged carbohydrate restriction may upregulate ketolytic capacity and could therefore modulate the response to exogenous ketone ingestion. This study investigated the impact of increasing [...] Read more.

Background/Objectives: Exogenous ketone supplementation has been proposed to enhance endurance performance by altering substrate metabolism and sparing muscle glycogen. Prolonged carbohydrate restriction may upregulate ketolytic capacity and could therefore modulate the response to exogenous ketone ingestion. This study investigated the impact of increasing circulating ketone bodies through exogenous ketone supplementation on endurance performance in athletes chronically adapted to a ketogenic diet. Methods: Participants (n = 9 recreationally active males, with ≥1 year of ketogenic adherence) visited the lab four times. The first visit determined their

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O₂max. The second visit accustomed them to test procedures. In a counterbalanced design, visits three and four tested the consumption of a 60 g carbohydrate beverage (CHO), or a beverage comprising 60 g carbohydrate and 0.5 g/kg 1,3-butanediol (CHO + BD). This was followed by a 60 min set-intensity exercise bout, followed by a 16.1 km time trial. Results: βHB significantly increased in the CHO + BD group (rest: 0.72 ± 0.33 mmol/L; post-exercise: 1.69 ± 0.30 mmol/L) compared to CHO (rest: 0.80 ± 0.53; post-exercise: 0.55 ± 0.30) (p < 0.001). There was no significant difference in time trial performance between groups (1606 ± 138 s; 1620 ± 134 s; p > 0.05). During set intensity exercise, there was no significant main effect of supplementation on lactate concentration, substrate oxidation, oxygen consumption at a fixed workload, RPE or heart rate (p > 0.05). However, glucose was significantly lower at minutes 40 and 60 of set intensity exercise in CHO + BD compared to CHO. Conclusions: No significant effect of 1,3-butanediol ingestion on endurance performance was detected in this sample of nine chronically ketogenic male athletes. βHB significantly increased from resting levels; however, time trial performance did not differ between conditions. Given the small sample and limited statistical power, these preliminary findings indicate no detectable ergogenic effect under the present conditions rather than evidence of no effect, and larger studies are warranted. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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17 pages, 2376 KB

Open AccessArticle

Effects of Menthol Mouth Rinsing on Performance and Surface EMG Activity During Heat-Stressed Cycling

by Kierstyn V. Hawke, Ryan C. A. Foley, Nicholas J. La Delfa and Heather M. Logan-Sprenger

Nutrients 2026, 18(7), 1134; https://doi.org/10.3390/nu18071134 - 1 Apr 2026

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Abstract

Objective: This study investigated the effects of menthol (MEN) mouth rinsing (MR) on cycling performance, neuromuscular activation, and perceptual responses during high-intensity exercise in the heat. Methods: A total of 10 trained adolescent male cyclists (16.7 ± 1.3 yrs; VO_2peak: 62.3 [...] Read more.

Objective: This study investigated the effects of menthol (MEN) mouth rinsing (MR) on cycling performance, neuromuscular activation, and perceptual responses during high-intensity exercise in the heat. Methods: A total of 10 trained adolescent male cyclists (16.7 ± 1.3 yrs; VO_2peak: 62.3 ± 7.6 mL·kg⁻¹·min⁻¹) completed a familiarization and two randomized, single-blind trials using a modified variable cycling test (M-VCT) in the heat (31.45 ± 0.59 °C; 23.40 ± 2.55% RH). The participants rinsed with 0.01% L-menthol or a placebo every 6 min during exercise. Power output (PO), cadence (RPM), rating of fatigue (ROF), affective feeling (FS), and surface electromyography (sEMG) were recorded. Results: Menthol MR significantly increased mean PO by 1.67 ± 1.59% (MEN: 177.1 ± 33.0 W; PLA: 174.1 ± 32.1 W; p = 0.002; d = 1.42) and enhanced cadence (MEN: 87.4 ± 5.1 RPM; PLA: 84.5 ± 5.2 RPM; p = 0.027; d = 0.84), particularly during high-intensity intervals. No significant differences were observed in ROF or FS between conditions (p > 0.05). Five muscles were monitored for activation (RF, VM, VL, TA, Gast). A significant main effect of time demonstrated decreased activation in VM, TA, RF, and Gast. VL showed a trend toward a main effect of condition (p = 0.057), with lower activation in MEN. Both VL and RF exhibited significant condition × lap interactions (p = 0.007 and p = 0.017), with progressively lower activation in MEN as fatigue progressed. Conclusions: Menthol MR significantly improved cycling performance in the heat without altering perceptual or physiological strain. Some muscles demonstrated reduced activation with menthol MR, and further study is needed to confirm the magnitude of ergogenic effects and elucidate the physiological mechanism. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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13 pages, 465 KB

Open AccessArticle

Temporal Stability, Reproducibility and Predictability of Whole-Body Sweat Sodium Concentration During Prolonged Cycling in the Heat with Ad Libitum and Programmed Drinking

by Eric D. B. Goulet, David Jeker, Pascale Claveau, Thomas A. Deshayes, Timothée Pancrate, Mohamed El Fethi Abed, Antoine Jolicoeur Desroches, Martin D. Hoffman, Philippe Gendron, Claude Lajoie and Lisa Lehmann

Nutrients 2026, 18(6), 989; https://doi.org/10.3390/nu18060989 - 20 Mar 2026

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Abstract

Background: Leading sports medicine and nutrition organizations recommend replacing sodium losses during prolonged exercise; however, practical guidance for implementing sodium replacement strategies remains limited. Estimating sodium needs during exercise requires assessment of both whole-body sweat sodium concentration (WBSSC) and sweat rate. Objectives: This [...] Read more.

Background: Leading sports medicine and nutrition organizations recommend replacing sodium losses during prolonged exercise; however, practical guidance for implementing sodium replacement strategies remains limited. Estimating sodium needs during exercise requires assessment of both whole-body sweat sodium concentration (WBSSC) and sweat rate. Objectives: This study focused on WBSSC by examining its temporal stability, reproducibility, and predictability during prolonged cycling exercise while drinking according to two hydration strategies. Methods: Using a randomized, crossover, counterbalanced design, eight highly trained men completed two 5 h cycling sessions (183 ± 14 W, 30 °C) while consuming fluids either in a programmed (P) or ad libitum (A_L) fashion. Sweat was collected with patches applied on the forearm for ~20 min before sampling, which occurred at ~40, 130, 220, and 290 min. Local sweat sodium concentration was converted to WBSSC using a validated equation. Results: A main effect of time was observed for WBSSC (p < 0.05), with only the 40 min time point differing from later measurements; no condition or interaction effects were detected. The within-trial typical variation in WBSSC was 7.2 mmol·L⁻¹ for P and 6.1 mmol·L⁻¹ for A_L, while the between-trial typical variation was 5.6 mmol·L⁻¹. The WBSSC measured at 40 min predicted mean exercise WBSSC with good precision and moderate stability (y = 0.2738 + 1.3397x, R² = 0.87, standard error of the estimate = 5.4 mmol·L⁻¹, 95% confidence interval slope = 0.82–1.86 mmol·L⁻¹). Conclusions: These findings indicate that during prolonged cycling exercise, WBSSC (1) varies trivially within and between trials; (2) can reasonably be predicted using a single sweat sample and; (3) is not influenced by P or A_L drinking. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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17 pages, 1125 KB

Open AccessArticle

Impact of Mango Puree Supplementation on Inflammatory, Muscle Damage, and Selected T-Cell Biomarkers in Elite Beach Volleyball Players During Regular Training

by Wason Parklak, Saksayam Sawaengwaisayasuk, Nattapong Chaipatpreecha, Bandhita Wanikorn, Surat Komindr, Narongsuk Munkong, Watunyou Khamros, Teeraphan Sangkaew, Metawee Duangjinda and Surasawadee Somnuk

Nutrients 2026, 18(3), 525; https://doi.org/10.3390/nu18030525 - 4 Feb 2026

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Abstract

Background/Objectives: Mango is a tropical fruit rich in polyphenols and carotenoids that may support recovery-related physiological responses during athletic training. This study examined the effects of mango puree supplementation on inflammatory biomarkers, muscle damage, and selected T-cell subsets in Thai men’s national [...] Read more.

Background/Objectives: Mango is a tropical fruit rich in polyphenols and carotenoids that may support recovery-related physiological responses during athletic training. This study examined the effects of mango puree supplementation on inflammatory biomarkers, muscle damage, and selected T-cell subsets in Thai men’s national beach volleyball players during regular training. Methods: Fifteen male athletes completed a pilot randomized, single-blind, crossover trial. Participants consumed the mango puree or placebo (600 g/day) for 4 weeks, separated by a 2-week washout period. Blood samples and physiological measurements were collected at baseline and at the end of each intervention period. Outcomes were analyzed using linear mixed-effects models. Results: Mango puree supplementation was associated with lower concentrations of C-reactive protein (mean difference: −1.6 mg/L; 95% CI: −2.1 to −1.1; p < 0.001), interleukin-6 (−0.7 pg/mL; 95% CI: −1.2 to −0.3; p = 0.003), and creatine kinase (−290.1 U/L; 95% CI: −356.1 to −224.1; p < 0.001) compared with the placebo. The percentage of CD4+ T cells (9.82 percentage points; 95% CI: 5.0 to 14.6; p < 0.001) and the CD4/CD8 ratio (0.37; 95% CI: 0.11 to 0.63; p = 0.007) were higher during mango puree supplementation, while CD8+ T-cell percentage did not differ between conditions. No significant treatment effects were observed for body composition parameters or blood pressure (all p > 0.05). Total energy intake remained unchanged across intervention periods (p > 0.05). Conclusions: Mango puree supplementation during regular training was associated with lower inflammatory and muscle damage biomarkers and alterations in selected T-cell subsets compared with the placebo. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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10 pages, 740 KB

Open AccessArticle

Effects of Marathon Running on Skin and Plasma Carotenoids in Endurance Runners

by Damon Joyner, Tracy M. Covey, Leigh Komperda, Margarita Lopez, Saori Hanaki, Bryan Dowdell, Stacie Wing-Gaia, Qi Jin, Jamie Stein and David Aguilar

Nutrients 2026, 18(3), 437; https://doi.org/10.3390/nu18030437 - 29 Jan 2026

Cited by 1 | Viewed by 1030

Abstract

Background/Objectives: Carotenoids are pigmented phytochemicals known for their antioxidant properties, known to protect against oxidative damage, especially in the context of intense exercise. The purpose of this paper was to observe and analyze the short-term effects of running a full marathon on skin [...] Read more.

Background/Objectives: Carotenoids are pigmented phytochemicals known for their antioxidant properties, known to protect against oxidative damage, especially in the context of intense exercise. The purpose of this paper was to observe and analyze the short-term effects of running a full marathon on skin and plasma carotenoid levels in endurance runners. Methods: This study recruited 24 healthy endurance runners (12 male, 12 female; mean age 37 years) registered for a 26.2-mile marathon. Skin carotenoid (SC) measures were taken via reflection spectroscopy, and plasma carotenoid concentrations (lycopene and β-carotene) were assessed via HPLC at three time points: pre-race, immediately post-race, and 48 h post-race. Changes across time were analyzed using repeated-measures ANOVA. Results: Skin carotenoid levels significantly changed over time, dropping from pre-race to post-race (p < 0.001), reflecting rapid utilization. At 48 h post-race, SC levels rebounded significantly, exceeding baseline measurements (p = 0.019). Plasma lycopene concentrations increased significantly from pre-race to post-race (p = 0.018) and remained elevated at 48 h. Plasma β-carotene concentrations showed no statistically significant change. Conclusions: The significant acute depletion of SC levels immediately following the marathon reflects the rapid utilization of these dermal antioxidants in response to the high oxidative stress generated by intense exercise. The elevation in plasma lycopene may reflect hemoconcentration resulting from intense activity and possible mobilization from tissue stores. The rapid rebound and overshoot in SC levels 48 h after the race are consistent with a recovery pattern of dermal carotenoid levels following acute depletion. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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22 pages, 1662 KB

Open AccessArticle

Ashwagandha Root Extract Stabilises Physiological Stress Responses in Male and Female Team Sports Athletes During Pre-Season Training

by Olivia C. Coope, Esteban Otaegui, Manolo Suárez, Alex Levington, Maria Abad-Sangrà, Beth Lloyd, Tilly J. Spurr and Blanca Roman-Viñas

Nutrients 2026, 18(2), 230; https://doi.org/10.3390/nu18020230 - 12 Jan 2026

Cited by 2 | Viewed by 11110

Abstract

Objectives: This study investigates the effects of 600 mg/day Ashwagandha root extract on physiological stress biomarkers, perception of recovery, muscle strength and aerobic capacity in team sports athletes during pre-season training, a period associated with elevated cortisol and accumulated training stress. Methods [...] Read more.

Objectives: This study investigates the effects of 600 mg/day Ashwagandha root extract on physiological stress biomarkers, perception of recovery, muscle strength and aerobic capacity in team sports athletes during pre-season training, a period associated with elevated cortisol and accumulated training stress. Methods: Fifty-six athletes (26.8 ± 4.4 years, 1.74 ± 0.10 m, 79.4 ± 17.3 kg, 11.0 ± 7.1 career years) across rugby, water polo and football were randomly assigned to an Ashwagandha (ASH; n = 28, 14 males and 14 females) or placebo (PLA; n = 28, 14 males and 14 females) group for 42 days. Salivary biomarkers were assessed after training, muscle strength and aerobic capacity were measured during training, and perception of recovery was evaluated with Hooper Index (HI) the following day. Mixed ANOVA was used to determine group × time interactions and Bonferroni post hoc analyses were conducted for multiple pairwise comparisons. Results: In female athletes, salivary cortisol increased significantly in PLA (p = 0.001), while recovery parameters such as the overall HI score (p = 0.001), Delayed Onset Muscle Soreness (DOMS) (p = 0.008) and perception of fatigue (p = 0.026) scores improved significantly in ASH. In males, salivary cortisone increased significantly in PLA (p = 0.022), while Countermovement Jump (CMJ) improved significantly in ASH (p = 0.018). Pull-up performance increased in both PLA (p = 0.004) and ASH (p < 0.0001) in males. Conclusions: Supplementation with 600 mg/day of Ashwagandha root extract for 42 days may stabilise stress biomarkers, improve perception of recovery and enhance muscle strength in team sports athletes during pre-season training. The trial is registered on ClinicalTrials.gov with the ID NCT07041853. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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22 pages, 1890 KB

Open AccessArticle

Dose–Response Effects of Short-Term Rhodiola rosea (Golden Root Extract) Supplementation on Anaerobic Exercise Performance and Cognitive Function in Resistance-Trained Athletes: A Randomized, Crossover, Double-Blind, and Placebo-Controlled Study

by Majid S. Koozehchian, Andrew T. Newton, Gina Mabrey, Faith M. Bonness, Rafaela Rafajlovska and Alireza Naderi

Nutrients 2025, 17(23), 3736; https://doi.org/10.3390/nu17233736 - 28 Nov 2025

Cited by 2 | Viewed by 10776

Abstract

Background: Rhodiola rosea (RR) is marketed as an adaptogen; however, evidence for acute/short-term effects—and especially dose–response effects—in trained adults across performance and cognition is limited. Objective: Test whether RR improves resistance performance (strength, power) and executive function in resistance-trained adults using a randomized [...] Read more.

Background: Rhodiola rosea (RR) is marketed as an adaptogen; however, evidence for acute/short-term effects—and especially dose–response effects—in trained adults across performance and cognition is limited. Objective: Test whether RR improves resistance performance (strength, power) and executive function in resistance-trained adults using a randomized crossover with placebo and a capsule-free baseline. Methods: In a randomized, double-blind, crossover trial with four conditions—no-capsule control (CON), placebo (PL), low-dose RR (LDRR), and high-dose RR (HDRR). Twenty-seven resistance-trained adults completed the conditions. Day-7 testing included bench press (BP) and leg press (LP) 1-repetition maximum (1RM); a third set to failure at 60% 1RM with set-3 volume; Tendo mean/peak power; a 30 s Wingate; and the Stroop Color–Word Test. Secondary endpoints were Rating of Perceived Exertion (RPE), Readiness to perform using a Visual Analog Scale (VAS), and hemodynamics. Results: Versus CON, LDRR increased BP 1RM (+5.59 kg; p = 0.003), set-3 repetitions (+4.30; p < 0.001), set-3 volume (+168.6 kg; p < 0.001), and mean power (+29.7 W; p = 0.026). HDRR increased set-3 repetitions (+2.78; p = 0.005) and peak power (+34.2 W; p = 0.026), with a trend for set-3 volume (p = 0.086). LP 1RM exceeded CON with LDRR (+35.7 kg; p < 0.001) and HDRR (+47.7 kg; p < 0.001); contrasts vs. PL were significant. Wingate outcomes showed no consistent effects. Stroop improved vs. CON across all sections: Word +10.5 to +17.4 counts (p < 0.05), Color +6.1 to +12.0 (p ≤ 0.03), and Color–Word +10.2 to +18.9 (p < 0.001). Conclusions: Short-term RR consumption, regardless of dose or gender, improved resistance performance and significantly enhanced Stroop outcomes, with minimal changes in anaerobic cycling and RPE, and no consistent acute hemodynamic effects. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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10 pages, 739 KB

Open AccessArticle

Annual Vitamin D Status of World-Class British Swimmers Following a Standardised Supplementation Protocol for Three Years

by Josh W. Newbury, Richard J. Chessor, Guy M. Evans, Richard J. Allison, Charlie J. Roberts and Lewis A. Gough

Nutrients 2025, 17(7), 1270; https://doi.org/10.3390/nu17071270 - 5 Apr 2025

Cited by 1 | Viewed by 2737

Abstract

Background/objectives: British swimmers are at a heightened risk of vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D): <50 nmol∙L⁻¹) as their large indoor training volumes often restrict sunlight exposure, especially during the winter when daylight hours are reduced in the United Kingdom. [...] Read more.

Background/objectives: British swimmers are at a heightened risk of vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D): <50 nmol∙L⁻¹) as their large indoor training volumes often restrict sunlight exposure, especially during the winter when daylight hours are reduced in the United Kingdom. Previous research has recommended supplementation with 4000 IU∙day⁻¹ vitamin D₃ from October to March to offset vitamin D losses. However, no current study has analysed this approach over multiple seasons to assess if this is an appropriate strategy. Methods: Using a quasi-experimental design, twenty-nine world-class British swimmers (aged 16–30 years) provided a 10 mL venous blood sample (fasted) as part of their routine haematological screening in the September of three consecutive years (2018, 2019, and 2020). Serum 25(OH)D was determined by radioimmunoassay, and this result determined the length of the standardised vitamin D3 protocol (<30 nmol∙L⁻¹: 4000 IU∙day⁻¹ from September to March; 30–79 nmol∙L⁻¹: 4000 IU∙day⁻¹ from October to March; >75 nmol∙L⁻¹: no supplementation). Results: Mean serum 25(OH)D concentrations increased each year (2018: 76.4 ± 28.4 nmol∙L⁻¹, 2019: 91.5 ± 24.8 nmol∙L⁻¹, 2020: 115.0 ± 36.6 nmol∙L⁻¹, p < 0.001), which coincided with the eradication of vitamin D deficiency after one season (prevalence, 2018: 10%, 2019: 0%, 2020: 0%). In September 2020, 35% of swimmers had a serum 25(OH)D > 125 nmol∙L⁻¹, although it is currently debated whether this is a concern or a benefit for athletic populations. Conclusions: Supplementing with 4000 IU∙day⁻¹ of vitamin D₃ throughout the winter can increase the vitamin D status of swimmers. However, more frequent testing may be required to ensure that serum 25(OH)D remains within the sufficient range across the season (75–125 nmol∙L⁻¹). Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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14 pages, 1529 KB

Open AccessArticle

An Online Nutrition Education Program Targeting Intentions and Related Determinants Towards Dietary Supplement Use: An Application of the Theory of Planned Behavior

by Jana Daher, Margo Mountjoy and Dalia El Khoury

Nutrients 2025, 17(3), 557; https://doi.org/10.3390/nu17030557 - 31 Jan 2025

Cited by 4 | Viewed by 3455

Abstract

Background/Objectives: Dietary supplement use among varsity athletes is influenced by various psychological and social factors, yet there is limited evidence on the effectiveness of educational interventions in influencing these determinants. The aim of this study was to determine the effects of an online [...] Read more.

Background/Objectives: Dietary supplement use among varsity athletes is influenced by various psychological and social factors, yet there is limited evidence on the effectiveness of educational interventions in influencing these determinants. The aim of this study was to determine the effects of an online nutrition education program on improvements in intentions and related determinants towards the use of dietary supplements in varsity athletes at the University of Guelph in Canada. The theory of planned behavior served as the theoretical framework for examining these determinants as predictors of behavior change. Methods: A randomized wait-list controlled trial was conducted on a total of 30 varsity athletes, randomized into experimental (n = 18) and control (n = 12) groups. The experimental group received access to an online nutrition education program focused on sports nutrition and dietary supplements, while the control group did not have access during the study. Results: There was a significant (p < 0.05) intervention effect on varsity athletes’ attitudes (Mean1_(control) = 13.17; Mean1_{(experimental)} = 13.56; Mean2_(control) = 13.92; Mean2_{(experimental)} = 12.11), perceived behavioral control (Mean1_(control) = 15.92; Mean1_{(experimental)} = 16.11; Mean2_(control) = 16.33; Mean2_{(experimental)} = 18.39), and intentions (Mean1_(control) = 12.5; Mean1_{(experimental)} = 12.89; Mean2_(control) = 11.58; Mean2_{(experimental)} = 9.44) towards dietary supplement use. No significant changes were made to descriptive and injunctive norms. Conclusions: These findings suggest that this nutrition education program significantly improved intentions and related determinants towards dietary supplement use in varsity athletes. The absence of a successful change in subjective norm should be a focus for similar future interventions. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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19 pages, 3847 KB

Open AccessArticle

The Effect of Ingesting Alginate-Encapsulated Carbohydrates and Branched-Chain Amino Acids During Exercise on Performance, Gastrointestinal Symptoms, and Dental Health in Athletes

by Lotte L. K. Nielsen, Max Norman Tandrup Lambert, Jørgen Jensen and Per Bendix Jeppesen

Nutrients 2024, 16(24), 4412; https://doi.org/10.3390/nu16244412 - 23 Dec 2024

Cited by 4 | Viewed by 3921

Abstract

Background: This study aimed to compare the effects of a carbohydrate (CHO) hydrogel with (ALG-CP) or without (ALG-C) branched-chain amino acids, and a CHO-only non-hydrogel (CON), on cycling performance. The hydrogels, encapsulated in an alginate matrix, are designed to control CHO release, potentially [...] Read more.

Background: This study aimed to compare the effects of a carbohydrate (CHO) hydrogel with (ALG-CP) or without (ALG-C) branched-chain amino acids, and a CHO-only non-hydrogel (CON), on cycling performance. The hydrogels, encapsulated in an alginate matrix, are designed to control CHO release, potentially optimising absorption, increasing substrate utilisation, and reducing gastrointestinal distress as well as carious lesions. Methods: In a randomised, double-blinded, crossover trial, 10 trained male cyclists/triathletes completed three experimental days separated by ~6 days. During the experimental days, participants completed a standardised 2 h cycling bout (EX1), followed by a time-to-exhaustion (TTE) performance test at W_75%. Supplements were ingested during EX1. Results: Participants cycled ~8.8 (29.6%) and ~5.4 (29.1%) minutes longer during TTE with ALG-CP compared to ALG-C and CON, respectively. TTE was 65.28 ± 2.8 min with ALG-CP, 56.46 ± 10.92 min with ALG-C, and 59.89 ± 11.89 min with CON. Heart rate (HR) was lower during EX1 with ALG-CP (p = 0.03), and insulin levels increased more significantly during the first 45 min with ALG-CP. Plasma glucose and glucagon levels remained consistent across supplements, although glucagon was higher with ALG-CP before TTE. Post-exercise myoglobin levels were lower with ALG-CP compared to ALG-C (p = 0.02), indicating reduced muscle damage. Conclusions: While ALG-CP improved performance duration compared to ALG-C and CON, the difference did not reach statistical significance. Additionally, there was a lower HR during the cycling session, alongside a significantly lower level of myoglobin with ALG-CP. These findings suggest that ALG-CP may offer advantages in cycling performance and recovery. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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Review

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30 pages, 1702 KB

Open AccessReview

Adulteration of Sports Supplements with Anabolic Steroids—From Innocent Athlete to Vicious Cheater

by Daniela Puscasiu, Corina Flangea, Daliborca Vlad, Roxana Popescu, Cristian Sebastian Vlad, Sorin Barac, Andreea Luciana Rata, Cristina Marina, Ionut Marcel Cobec and Sorina Maria Denisa Laitin

Nutrients 2025, 17(19), 3146; https://doi.org/10.3390/nu17193146 - 1 Oct 2025

Cited by 6 | Viewed by 13145

Abstract

Some protein food supplements intended for athletes may be adulterated with pharmacologically active substances, including anabolic steroids and prohormones. The addition of these substances is aimed at enabling manufacturers to achieve rapid sales growth by promising quick increases in strength and muscle mass. [...] Read more.

Some protein food supplements intended for athletes may be adulterated with pharmacologically active substances, including anabolic steroids and prohormones. The addition of these substances is aimed at enabling manufacturers to achieve rapid sales growth by promising quick increases in strength and muscle mass. However, the consumption of these products will lead to a positive result in a routine anti-doping test, along with all of the consequences that will directly affect an athlete’s career and reputation. At the same time, the illicit use of anabolic steroids continues to evolve across numerous sport disciplines. Moreover, vicious cheaters try to cover up their illegal actions by using various pharmacological agents to mask detection in anti-doping tests. This narrative review focuses on two situations—the innocent athlete and the vicious cheater. The athlete involved in inadvertent doping will suffer the consequences of doping, making close collaboration with medical staff extremely important. The analytic strategies described here address anabolic steroid doping detection and cheating using masking agents. This approach, based on biochemical changes, examines how these substances interfere with the testosterone pathway, from synthesis to elimination. Using masking agents alters the steroid profile, and the modifications produced by each agent are the subject of a detailed presentation. For most honest athletes, these findings support the initiation, development, and refinement of strategies for identifying food supplements with added illegal substances. Every athlete must have access to these approaches in order to avoid becoming vulnerable to sports fraud. Full article

(This article belongs to the Special Issue Nutrition and Supplements for Athletic Training and Racing)

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