Physiologia

Background: We tested whether gene polymorphisms for angiotensin-converting enzyme (ACE, rs1799752) and tenascin-C (TNC, rs2104772) are associated with variability in fatigue resistance and metabolic strain during static lumbar exercise through interactions with chronic nonspecific lower back pain and habitual physical exercise levels (PA). Methods: Forty-eight patients and matched controls performed an isometric endurance test for lumbar extensors. Metabolic strain to longissimus muscle (oxygen saturation, lactate) and cardiovascular system (muscle hemoglobin, blood pressure) and holding time were monitored. Subjects were genotyped for rs1799752 (II, ID, DD) and rs2104772 (AA, AT, TT). Associations of variance with group, genotype, and PA were analyzed under a 5% false discovery rate. Results: The holding time was lower in patients than in controls (150.9 vs. 188.6 s). This difference was associated with both genotypes, as patients with DD-rs1799752-genotype (p = 0.007) and TT-rs2104772-genotype (p = 0.041) showed lower fatigue resistance. Muscle deoxygenation during exercise varied in positive association with the rs2104772-genotype and PA (p = 0.010, η2 = 0.236). Mean arterial blood pressure (p = 0.028, η2 = 0.108) and recovery of hemoglobin concentration (p = 0.003, η2 = 0.907) demonstrated complex group x rs2104772 interactions. Conclusions: Polymorphisms rs1799752 and rs2104772 influence back pain-related variability in lumbar fatigue resistance. rs2104772 was linked to cardiovascular strain during isometric exercise and recovery via muscle perfusion. Full article

Background: Menopause is a significant period in the life of a female; many hormonal and lifestyle changes occur, which can have a catastrophic effect on their health and well-being. Amongst these changes is the loss of muscle mass and strength. Resistance training is recommended for post-menopausal women; however, the role of protein in muscle mass and strength in this population is unclear. Methods: This narrative review discusses the research evidence regarding daily protein needs, dose and timings of intake, and protein quality. Results: Observational and interventional studies suggest post-menopausal females should ingest at least the RDA 0.8 g·kg⁻¹·d⁻¹ of protein, the dosing at each meal maybe important. Both whey and soy protein may provide some benefit to muscle strength. Conclusions: Overall, there is limited evidence and not of high quality, making it difficult to make inferences about the protein needs of post-menopausal females. Full article

Researchers have hypothesized that high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MOD) lead to different patterns of shear stress in the brachial artery. These differing patterns of shear stress are thought to partially explain the differing chronic adaptations to these two types of exercise. No study has directly compared blood flow characteristics during HIIE and MOD. Sixteen healthy males (Age: 23 ± 3 years) completed two randomly assigned exercise visits: HIIE (10 × 1 min intervals at 90–95% of HR_max with 1 min of recovery between) or MOD (30 min at 70% of HR_max) on an electronically braked cycle ergometer. Brachial artery blood flow velocity and diameter were measured for a total of 12 min during each of the exercise sessions. Both anterograde blood flow (MOD: 191.3 ± 80.3 mL/min, HIIE: 153.9 ± 67.5 mL/min, p = 0.03) and shear rate (MOD: 203.5 ± 78.1 s⁻¹, HIIE: 170.8 ± 55.5 s⁻¹, p = 0.04) were higher during MOD compared to HIIE. Both retrograde blood flow (MOD: −48.7 ± 21.3 mL/min, HIIE: −63.9 ± 23.3 cm/s, p < 0.01) and shear rate (MOD: −51.5 ± 19.8 s⁻¹, HIIE: −73.8 ± 28.4 s⁻¹, p < 0.01) were of greater magnitude during HIIE compared to MOD. During exercise, brachial artery diameter (p = 0.34) did not differ between HIIE and MOD. Continuous moderate cycling exercise leads to higher brachial artery anterograde shear rate and blood flow, but lower retrograde shear rate and blood flow when compared to high-intensity interval exercise. These differences during exercise in blood flow characteristics could shed light on the differing chronic adaptations to these two types of exercise. Full article

Citrulline malate (CM) has been touted as a nutritional ergogenic aid for sports performance, with purported mechanisms of increased muscle blood flow, ammonia clearance, and adenosine triphosphate resynthesis. Combined, these physiological benefits may be best applied to whole-body endurance exercises, such as swimming, though this postulate has not yet been explored. In a double-blind, randomised, and crossover design, 11 national-level swimmers (age: 17 ± 3 years, height: 1.71 ± 0.05 m, body mass: 60.6 ± 8.3 kg) from a high-performance swimming club ingested either 15 g CM or a placebo (PLA) 60 min before six × 300 m freestyle bouts (at 4.5 min intervals). Blood lactate, blood pressure, and ratings of perceived exertion were measured at baseline, 60 min post-ingestion, and immediately post-exercise. Neither mean 300 m swimming time (CM: 212.0 ± 9.6 vs. PLA: 212.8 ± 7.7 s, p = 0.683, g = 0.09) nor any individual swimming bouts (p = 0.679, Pŋ² = 0.02) were improved with CM ingestion. Moreover, no differences in any physiological or subjective measures were identified between conditions (all p > 0.05). Whether the proposed CM mechanisms were active was unclear as more direct physiological measures (i.e., plasma NO, ammonia) may have been required. Resultantly, these observations do not support an ergogenic effect of acute CM ingestion in highly trained swimmers. Full article

Recommendations for endurance exercise prescription are often based on percentages of heart rate (HR) or the volume of oxygen consumption ($\dot{\mathrm{V}}$O₂) maximum or reserve that is extrapolated to a power output (P) or velocity. Previous work has demonstrated dissociations of the expected responses to exercise anchored to the critical heart rate (CHR) compared with the P associated with CHR. However, it is unclear if similar dissociations due to reductions in P to maintain the designated intensity would be present during exercise anchored to the $\dot{\mathrm{V}}$O₂ associated with CHR ($\dot{\mathrm{V}}$O₂CHR). The purpose of this study was to examine the patterns in physiological ($\dot{\mathrm{V}}$O₂, HR, P, respiration rate [RR], muscle oxygen saturation [%SmO₂]), neuromuscular (electromyographic and mechanomyographic amplitude [EMG AMP, MMG AMP], mean power frequency [EMG MPF, MMG MPF]), and perceptual (rating of perceived exertion [RPE]) responses during exercise at $\dot{\mathrm{V}}$O₂CHR ($\dot{\mathrm{V}}$O₂-clamp). On separate days, ten participants (age: 25 ± 4 yr) performed a graded exercise test and four constant P trials at 85–100% of peak P (PP) to derive CHR and $\dot{\mathrm{V}}$O₂CHR. Responses were recorded during a trial to exhaustion at $\dot{\mathrm{V}}$O₂CHR (32.86 ± 7.12 mL·kg⁻¹·min⁻¹; T_Lim = 31.31 ± 21.37 min) and normalized in 10% intervals of T_Lim to their respective values at PP. The one-way repeated-measures ANOVA with post hoc, Bonferroni-corrected, pairwise comparisons indicated differences (p < 0.001) from baseline for HR (mean ± SD %change = 8 ± 3%), RR (43 ± 38%), P (−15 ± 5%), EMG MPF (10 ± 8%), and RPE (65 ± 38%), but no differences (p = 0.077–0.955) for %SmO₂ (−17 ± 53%), EMG AMP (−3 ± 16%), MMG AMP (40 ± 61%), and MMG MPF (1 ± 7%). The loss in performance observed during $\dot{\mathrm{V}}$O₂-Clamp exercise may provide a quantification of the inefficiency associated with the $\dot{\mathrm{V}}$O₂ slow component phenomenon. The neuromuscular responses suggested constant muscle excitation despite the reductions in P, but the metabolic and perceptual responses suggested a combination of feedforward and feedback mechanisms regulating T_Lim. Future studies should further examine responses to the $\dot{\mathrm{V}}$O₂-Clamp exercise at a uniform threshold. Full article

Nutritional status plays a vital role in regulating ovary activity. This regulation is mediated by the hypothalamus–pituitary–gonad axis and by effects exerted directly on the ovary. Therefore, to achieve the best reproductive performance, it is essential to know how the nutritional status affects the secretion of GnRH, gonadotrophins, and sex steroid hormones. Adequate body reserves and energy balance are critical for optimal reproductive performance in sheep and goats. However, over- or under-conditioned animals experience issues like extended anestrus, irregular ovarian cycles, and reduced conception. Body condition scoring allows for the evaluation of the relationships between adiposity, nutritional status, and fertility. Acute feed deficits briefly stimulate processes, but chronic restrictions suppress pulsatile LH release, disrupting ovarian function. The process of follicle development is a very complex one which involves intricate interactions between the pituitary gonadotrophins and metabolic hormones as well as between the locally produced factors by the ovarian somatic and germ cells including the IGF system and the TGF-β superfamily members. Genotype and nutrition are factors that have an impact on follicular development, and seasonal factors are also involved. This review will give a brief overview on how the body condition can be evaluated and the effects of nutrition on the hypothalamus–pituitary–gonad axis and ovarian activity, which are responsible for reproductive regulation. This paper presents a clear and reasonable summary of the pathway that runs from the nutritional status of small ruminants to ovarian activity through the hypothalamic–pituitary–gonadal axis. This review summarizes methods for body condition evaluation in small ruminants and evidence regarding acute versus prolonged nutritional impacts on the hypothalamic–pituitary–gonadal axis and ovarian activity controlling reproduction. Full article

Exercise physiology is the science that studies the processes of physical activity and their impact on the body. It usually requires a multidisciplinary approach with a team of experts because of the multiple physiological systems involved. At the cellular level, exercise can trigger a cascade of events that involve metabolic pathways, muscle recruitment and conditioning, neuromuscular adaptations, and optimization of energy production. On a systematic level, this has involved the cardiovascular system, the respiratory system, the musculoskeletal system, the peripheral and central nervous systems, and even the endocrine system to improve adaptation to meet the demands of exercise, improving strength and endurance with the goal of maximizing performance. This field, which began largely with a focus on the kinetics of oxygen consumption and the relationship between aerobic and anaerobic metabolism, has expanded with technological advancements such as wearable devices, advanced imaging techniques, and genomics, which has allowed for a greater appreciation of the physiologic responses of exercise at the level of molecular and cellular interactions. Recently, this science has evolved into the study of overall health promotion and disease prevention to meet individual fitness needs and goals. This philosophy, which is captured by the motto “Exercise is Medicine”, has been adopted as a Global Health Initiative by the World Health Organization (WHO). Despite the advancements in technology and impactful, large-scale studies, a variety of questions, such as how physical activity interacts with aging to affect physical and cognitive function, how inactivity influences acute and chronic disease states, and how we maximize human performance in extreme conditions like microgravity environments, remain. The purpose of this review is to present and discuss established concepts, controversial topics, and unanswered questions within exercise physiology that have allowed this field to become a science that embraces the overall well-being of individuals. Full article

Hydrocephalus is caused by an overproduction of cerebrospinal fluid (CSF), an obstruction of fluid movement, or improper reabsorption. CSF accumulation in the brain’s ventricles causes ventriculomegaly, increased intracranial pressure, inflammation, and neural cell injury. Hydrocephalus can arise from brain trauma, hemorrhage, infection, tumors, or genetic mutations. Currently, there is no cure for hydrocephalus. Treatments like shunting and endoscopic third ventriculostomies are used, but, unfortunately, these therapeutic approaches require brain surgery and have high failure rates. The choroid plexus epithelium (CPe) is thought to be the major producer of CSF in the brain. It is a polarized epithelium that regulates ion and water movement from a fenestrated capillary exudate to the ventricles. Despite decades of research, control of electrolyte movement in the CPe is still not fully understood. This review discusses important transporters on the CPe, how some of these are regulated, and which of them could be potential targets for hydrocephalus treatment. To advance the development of hydrocephalus treatments, physiologically relevant preclinical models are crucial. This review covers some of the current animal and cell culture methods used to study hydrocephalus and highlights the need to develop standardized preclinical models that are used by multiple investigators in order to replicate critical findings and resolve controversies regarding potential drug targets. Full article

Prediabetes, a pivotal phase in glucose metabolism between normalcy and diabetes, exerts a profound influence on the aging process and the risk of age-related diseases. This comprehensive review delves into the intricate web of blood-based biomarkers that collectively expedite senescence, marking the transition from a state of health to age-related complications. Key findings underscore the significance of diverse biomarkers, such as telomere length, p16INK4a, senescence-associated secretory phenotype (SASP) factors, DNA methylation clocks, advanced glycation end products (AGEs), inflammatory and oxidative stress markers, circulating hormones, and additional factors such as folate, B12, and osteocalcin. Not only do these biomarkers serve as indicators of senescence but they also actively fuel chronic inflammation, oxidative stress, and metabolic dysregulation, all of which contribute to accelerated aging. The implications of this understanding are profound, as prediabetes emerges as a critical period in an individual’s life, influencing various physiological systems, including the vascular and neural systems, metabolic functions, hormonal regulation, and bone health. Recognizing the profound influence of prediabetes on senescence provides a foundation for personalized intervention strategies to mitigate age-related complications and promote healthy aging. Future research directions call for a more diverse array of biomarkers, the in-depth exploration of their roles, and the development of tailored precision medicine strategies to ensure a holistic understanding and effective management of prediabetes-induced senescence and its implications for aging. This knowledge has far-reaching implications for public health and clinical practice, emphasizing the need for early detection and intervention in prediabetic individuals to enhance the quality of life in an aging population with diverse needs. Full article

(1) Background: The influence of estrogen on cognitive and perceptual functions is debated. Some research suggests that estrogen increases arousal, improving cognitive function, while others propose that increased arousal might reduce performance in certain tasks. This study investigates the effects of menstrual cycle phase and estrogen levels on lightness perception in cycling women and hormonal contraceptive (HC) users. (2) Methods: Sixteen women (nine with natural cycles and seven HC users) completed three sessions aligned with different menstrual cycle phases. During these sessions, participants adjusted the luminance of five test stimuli (representing blue, green, green-yellow, yellow, and red) until they matched a flickering reference white stimulus. Lightness was calculated as the ratio of the reference stimulus luminance (5 cd/m²) divided by the test luminance required to match. Estrogen levels were also determined for each participant from saliva samples collected on the morning of each session. The effects of wavelength and menstrual cycle phase on lightness perception were analyzed, followed by post hoc comparisons and correlations between lightness perception and estrogen levels for both cycling women and HC users. (3) Results: Lightness varied by menstrual phase (MCP) in cycling women and was slightly higher during the low estrogen menstrual phase compared to peri-ovulation or luteal phases. In HC users, lightness measures were equivalent across phases. For cycling women, lightness was negatively correlated with estrogen for the green and green-yellow stimuli. There were no such associations among HC users. (4) Conclusions: This report challenges the concept that high estrogen phases of the menstrual cycle always positively influence perception. Conversely, these results revealed that—at least in cycling, non-hormonal contraceptive users—lightness perception was both at a maximum during the low estrogen menstrual phase and negatively associated with estrogen levels across all tested wavelengths. Full article

The aging of the global population is a significant and complex phenomenon with far-reaching implications for healthcare systems and society. By 2030, it is projected that the number of individuals over the age of 65 will increase by nearly 1 billion, largely due to advancements in healthcare and improvements in quality of life. Aging is a multifaceted process that encompasses a wide array of changes, spanning from the cellular level to the intricate physiological systems of the human body. At the central nervous system level, aging represents a major risk factor for conditions such as depression and cognitive impairment, which are likely linked to neuroinflammatory processes and can potentially lead to more severe dementias, including Alzheimer’s disease (AD). The higher prevalence of AD in women compared to men has led to speculation that the onset of menopause and associated phenomena, particularly the decline in estrogen levels, may play a role in the development of the disease. Furthermore, research has shown that physical exercise confers both physical and mental health benefits to older adults, with women potentially experiencing the greatest advantages. Understanding the multifaceted nature of aging and its implications for health will ensure that older adults receive the support and care essential for maintaining their health and quality of life. Full article

Background: The positive effects of prolonged every-other-day (EOD) feeding include decreased body weight and prolonged life span, but also changes in liver metabolism and functions. In the present paper, our aim was to examine the expression of adiponectin (ADIPOQ), leptin, and their receptors (ADIPOR1, ADIPOR2, and LEPR) in the liver tissue of EOD-fed mice in comparison to ad libitum (AL)-treated mice. Methods: After 9 months of EOD treatment, liver tissue was harvested and prepared for analysis. RT-PCR, protein semi-quantitative estimation, and cellular immunolocalization was performed. Results: We noted a decreased expression of leptin in the liver tissue of the EOD male mice in comparison to the AL mice on the protein level. ADIPOQ receptor R1 protein expression was decreased in the liver of EOD-fed male mice, while the expression of ADIPOR2 on the protein level was increased in the EOD animals. Conclusions: To the best of our knowledge, this is the first report showing ADIPOQ and leptin immunolocalization in the liver tissue in a dietary regime experiment. Decreases in leptin expression and IL-6 expression in liver tissue and increases in ADIPOR2 expression may be partly responsible for the beneficial effects of EOD treatment in the liver, including the decrease in inflammation. Further studies are needed to establish whether these changes depend on factors like the type of treatment, species, strain, gender, time of treatment, and others. Full article

When thinking of skin disease, cancer comes up almost immediately as an example. While the American Cancer Society lists 6 major cancer types, the National Institute of Arthritis and Musculoskeletal and Skin Diseases identifies 13 significant benign skin disorders, reflecting the diversity of skin conditions in dermatology. This topical review aims to provide an overview of the pathophysiology of these major skin cancers and disorders and to summarize conventional diagnostic methods and current treatment approaches. Full article

Heat stress and cutaneous capsaicin application act independently to reduce mean arterial blood pressure (MAP) at rest. The present study investigated whether a mixed intervention might alleviate to a greater extent the hypertensive response to isometric exercise. An end-exercise systolic blood pressure (SBP) lower than 215 mmHg or higher than 220 mmHg was set for the inclusion in the group observed with typical (CON, n = 9) or hypertensive (HRE, n = 8) response to dynamic exercise, respectively. The participants performed four trials held in thermoneutral (TN:23 °C) or hot (HT:33 °C) conditions with capsaicin (CA:4.8 mg·patch⁻¹) or placebo (PL) patches (12 × 18 cm²) applied to their two quadriceps, left pectoralis major and left scapula. The trials comprised: a 5 min baseline period preceding patch application, a 30 min rest period and a 5 min isometric handgrip exercise (20% maximal voluntary contraction, 10.1 ± 1.9 kg). Thermoregulatory and cardiovascular data were analyzed using mixed three-way ANOVA. End-resting MAP and pain sensation were higher in PL-TN (p = 0.008) and CA-HT (p = 0.012), respectively. End-exercise SBP tended to be higher in HRE individuals across environments (p = 0.10). Total peripheral resistance and MAP remained lower in HT across groups (p < 0.05). Despite the alleviating effect of the heat stressor, an augmented burning sensation-induced peripheral vasoconstriction might have blunted the pressure-lowering action of capsaicin. Full article

Polyunsaturated fatty acid (PUFA) metabolites play important roles in the modulation of vascular tone, heart rate variability (HRV), and cardiovascular diseases. This study was undertaken to examine the relationship between HRV and the plasma levels of essential acids. Methods: Highly trained cross-country skiers participated in the study (n = 19). Time-domain and frequency-domain HRV analyses were performed. The plasma levels of fatty acids were determined using gas–liquid chromatography. Results: Plasma eicosapentaenoic acid and docosahexaenoic acid were found to be negatively correlated with resting heart rate (HR) (p = 0.026). The plasma levels of alpha-linolenic acid (ALA) were positively associated with the relative value of high-frequency power (rs = 0.465, p = 0.045) and negatively correlated with the sympathovagal balance ratio (rs = −0.493, p = 0.032) and the absolute and relative values of low-frequency power (rs = −0.490, p = 0.028). The plasma levels of arachidonic acid (ARA) were positively associated with the relative value of high-frequency power (rs = 0.59, p = 0.006) and negatively correlated with the sympathovagal balance ratio (rs = −0.54, p = 0.017) and the relative values of low-frequency power (rs = −0.52, p = 0.022). No correlation was found between n6/n3 and HRV parameters except for HR and pNN50. Conclusions: n-3 PUFAs and ARA play an important role in the autonomic regulation of heart rate in highly trained skiers. Athletes with substantial deficiencies in plasma ALA and excess levels of ARA had increased sympathetic and decreased parasympathetic activity. Full article

Nitrogen is the most commonly managed mineral nutrient in olive groves because it is essential for plant growth. The precise management of N fertilization in olive cultivation is still not fully clarified, but it is essential for providing sustainable production. A nitrogen fertilizer experiment with olive trees (cv. Kalinioti) was carried out over a six-year period. Seven levels of nitrogen fertilizer given as ammonium nitrate (control, 1, 2, 3, 4, 5, and 6 kg/tree) were annually applied in order to determine the effect of nitrogen on vegetative growth, fruit set, fruit weight, yield, maturation index, and leaf N, P, and K concentrations. The results indicate that, under these conditions, application of up to 4 kg NH₄NO₃/tree significantly increased yield to 62.5 kg/tree compared to the control (37.09 kg/tree). The positive effect was attributed to the initial and final fruit set increases (7.63 and 3.73%, respectively at 4 kg NH₄NO₃/tree). However, the weight of 100 olives (W₁₀₀ = 331 g) at 4 kg NH₄NO₃/tree obtained during harvest was considerably lower compared to the control (W₁₀₀ = 384 g). Higher nitrogen rates decreased yield while increasing overall shoot growth. Nitrogen fertilization did not significantly influence the oil content of olive fruit. Fruit weight, maturation index, and concentration of oil reached maximum levels in the beginning of December, indicating a suitable start to olive harvesting. The concentration of N in olive leaves increased from 1.23% to 2.38% as fertilizer levels increased from 0 to 6 kg NH₄NO₃. Maximum yield was achieved at a level of 6 kg NH₄NO₃/tree, which corresponded to 2.01% N in leaves. The results suggest that application of 3 kg NH₄NO₃/tree can be recommended for table olive production, due to the fact that fruit weight was not decreased, while fertilization with 4 kg NH₄NO₃/tree was suitable for oil olives. Full article

Sleep staging has a very important role in diagnosing patients with sleep disorders. In general, this task is very time-consuming for physicians to perform. Deep learning shows great potential to automate this process and remove physician bias from decision making. In this study, we aim to identify recent trends on performance improvement and the causes for these trends. Recent papers on sleep stage classification and interpretability are investigated to explore different modeling and data manipulation techniques, their efficiency, and recent advances. We identify an improvement in performance up to 12% on standard datasets over the last 5 years. The improvements in performance do not appear to be necessarily correlated to the size of the models, but instead seem to be caused by incorporating new architectural components, such as the use of transformers and contrastive learning. Full article

The objective of the present review was to evaluate the time-course of recovery of biochemical marker levels and physical performance after strenuous military training, and identify which biomarkers are affected. A systematic literature search was conducted using the databases MedLine (Ovid) and Web of Science (WoS) to identify studies until January 2023. Varying relevant search terms were used, related to military training, Special Forces, physical performance, and biomarkers. Records were based on strict inclusion and exclusion criteria. Twelve studies met the inclusion criteria and were selected for this review. A variety of physiological and psychological markers were measured, and military training lasted from 4 to 62 days, with recovery periods varying from 24 h to 6 weeks. Among these studies, full recovery was observed in two studies, while seven studies showed almost full (79–90%) recovery, and in three studies, 44–63% of markers recovered after the measured recovery period. However, in some studies, additional markers could be defined as recovered, depending on the criterion for recovery. In the majority of the studies, most of the measured variables recovered during the follow-up, but often, some variables remained unrecovered, and at times, only modest recovery was seen. It is important to point out that recovery duration depends on the duration and intensity of the military training stressor. Overall, resolution varies between the markers, and sometimes, recovery might not occur, even after prolonged recovery. Therefore, it is important to measure the recovery status of soldiers with both biomarkers and physical performance markers, especially after strenuous training, to maximize operational capability during prolonged missions. Full article

Firefighters are exposed to dangerous and often traumatic events due to the nature of their occupational demands. This repeated exposure to trauma combined with stressful work demands increases their risk for negative physiological and psychological health outcomes. The high prevalence of adverse health outcomes highlights the need for interventions to improve resiliency in firefighters. Resiliency is the ability to reduce the effect of crisis, rebound from adversity, and recover to pre-stimulus homeostasis. When traumatic exposures are unavoidable, as is the case with firefighters, it is important to buffer the resulting consequences on health. While resilience has a genetic component, interventions targeting physiological, psychological, and social components have been successful at improving resilience. These factors are of specific interest as increases in resilience have been linked to improved PTSD symptomology/severity, depression, anxiety, autonomic nervous system activation, hypothalamus–pituitary axis balance, and brain-derived neurotrophic factor. Therefore, the purpose of this review is to identify physiological and psychological components associated with resiliency and discuss strategies that may improve those components to ultimately increase resiliency in firefighters. The strategies discussed include exercise, social support, and mindfulness. Full article