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The cortisol awakening response (CAR) is commonly used as a marker of psychological stress; however, it is unknown whether CAR is affected by regular physical-exercise-induced stress. Purpose: To assess the relationship between training load and CAR. Methods: Recreational endurance athletes were recruited from local running clubs. Subjects (n = 15) completed training logs for 2 wk, with various training loads, including psychometric analysis (Recovery-Stress Questionnaire for Athletes). Subjects provided saliva samples each day immediately after waking and 30 min postwaking. Samples were analyzed for cortisol concentration via enzyme-linked immunosorbent assay and subsequently were analyzed for CAR and CAR%. Daily training load was calculated and analyzed as training impulse. Simple linear regression was used to assess the relationship between CAR and training impulse. Results: CAR (r2 =.352, P =.025) and CAR% (r2 =.373, P =.012) both showed a significant negative relationship with training load. Conclusions: These results suggest that CAR is affected by regular exercise training loads in recreational athletes. It is recommended that future CAR research control for fitness level and exercise training load in physically active populations. [ABSTRACT FROM AUTHOR]

Context: Individuals with an anterior cruciate ligament reconstruction (ACLR) are at an increased risk of developing posttraumatic osteoarthritis. How osteoarthritis risk factors, such as increased body mass index (BMI), may influence early changes in joint tissue metabolism is unknown. Objective: To determine the association between BMI and type 2 cartilage turnover in individuals with an ACLR. Design: Cross-sectional study. Setting: Research laboratory. Patients or Other Participants: Forty-five individuals (31 women, 14 men) with unilateral ACLR at least 6 months earlier who were cleared for unrestricted physical activity. Main Outcome Measure(s): Body mass index (kg/m²) and type 2 collagen turnover were the primary outcomes. Body mass index was calculated from objectively measured height and mass. Serum was obtained to measure type 2 collagen turnover, quantified as the ratio of degradation (collagen type 2 cleavage product [C2C]) to synthesis (collagen type 2 C-propeptide [CP2]; C2C : CP2). Covariate measures were physical activity level before ACLR (Tegner score) and current level of disability (International Knee Documentation Committee Index score). Associations of primary outcomes were analyzed for the group as a whole and then separately for males and females. Results: Overall, greater BMI was associated with greater C2C : CP2 (r = 0.32, P = .030). After controlling for covariates (Tegner and International Knee Documentation Committee Index scores), we identified a similar association between BMI and C2C: CP2 (partial r = 0.42, P = .009). Among women, greater BMI was associated with greater C2C : CP2 before (r = 0.47, P=.008) and after (partial r=0.50, P=.008) controlling for covariates. No such association occurred in men. Conclusions: Greater BMI may influence greater type 2 collagen turnover in those with ACLR. Individuals, especially women, who maintain or reduce BMI may be less likely to demonstrate greater type 2 collagen turnover ratios after ACLR. [ABSTRACT FROM AUTHOR]

Background. Overtraining (OVT) is a concern for many athletes. Immunological (increased interleukin-6 [IL-6]) and hormonal (increased cortisol [C], decreased free testosterone [fT]) biomarkers have been analyzed during training to detect OVT development. Methods. This study determined if resting levels of salivary IL-6, T, and C change during a pre-season resistance training (RT) program in 20 Division I American football players (mean ± SD: age = 19.1 ± 1.1 years; height = 185.4 ± 6.7 cm; mass = 102.0 ± 22.2 kg; body fat = 14.7 ± 7.6%). 1RM squat, bench press and Olympic-style clean, IL-6, C and T were assessed at baseline (WK1), week 4 (WK4), week 6 (WK6) along with psychological status (PS) to determine affective state. Results. 1RM (bench press: 121.6 ± 36.3 kg vs. 127.4 ± 35.9 kg, squat: 187.2 ± 30.2 kg, 190.9 ± 28.1 kg, clean: 116.8 ± 14.6 kg, vs. 119.2 ± 14.5 kg), IL-6 (1.42 ± 1.77 pg/mL vs. 5.60 ± 12.57 pg/mL) and C (2.57 ± 2.46 nmol/L vs. 5.33 ± 4.94) increased significantly from WK1 to WK6 (p < .05), fT decreased significantly (417.44 ± 83.63 pmol/L vs. 341.10 ± 87.79 pmol/L) from WK1 to WK6 (p < .05). PS was minimally affected during the study. Significant biomarker changes were detected, but no OVT was induced (i.e. performance improved). Conclusion. Therefore, directional changes in these biomarkers may not be sufficiently reflective of OVT in RT programs. [ABSTRACT FROM AUTHOR]

Background: Pubertal development status has implications for development of physical characteristics, performance, and injury risk in school-aged athletes. Objective: The objective of this study was to evaluate the ability of non-invasive measures of biological maturity to predict salivary free testosterone. Participants: A total of 61 physically active males (ages 6-16) participated in this study. Methods: Participants had their anthropometrics measured, completed the Pubertal Development Scale (PDS), and reported their birthdays and the heights of their biological parents. Exact chronological age and percent of predicted height were calculated. Resting salivary samples were collected and assessed for free testosterone levels using enzyme-linked immunosorbent assay procedures. Variables were entered into a stepwise linear regression to predict free testosterone. Results: The regression model was statistically significant (R2=0.716, F2,61=74.2, p<0.005) with chronological age (β=0.66, t60=7.587, p<0.005) and PDS (β=0.26, t60=3.02, p=0.004) remaining as significant predictors of free testosterone. Conclusions: Chronological age and PDS adequately predict salivary free testosterone levels in school-aged males and may be an appropriate tool to evaluate physical maturity in school-aged males quickly, cheaply, and accurately. [ABSTRACT FROM AUTHOR]

BACKGROUND: The purpose of this study was to investigate the extent of pre-exercise participation ('preparticipation') health screening in a heterogeneous cohort of adult cancer patients. METHODS: Patients (n = 413) with histologically confirmed solid or hematologic malignancy were categorized into preparticipation health screening risk stratification based on American College Sports Medicine (ACSM) recommendations. Risk of an exercise-related event was evaluated during a symptom-limited cardiopulmonary exercise test (CPET) with 12-lead electrocardiography (ECG). RESULTS: Participant risk was categorized as low risk (n = 59, 14%), moderate risk (n = 217, 53%), and high risk (n = 137, 33%). Mean peak oxygen consumption was 21.7 ± 6.7 mL/kg(-1) per minute(-1) or 19.5 ± 21.7% below age- and sex-predicted sedentary values. No major serious adverse events or fatal events were observed during CPET procedures. A total of 31 positive ECG tests were observed, for an event rate of 8%. ACSM risk stratification did not predict the risk of a positive test. Age, statin use, antiplatelet therapy use, cardiovascular disease, prior treatment with anthracycline or radiation therapy, and being sedentary were predictors of a positive test (all p < .10). CONCLUSION: The patient risk-stratification profile strongly suggests that the use of formalized preparticipation health screening is required in all oncology scenarios; however, risk of an exercise-induced event is low, suggesting that the use of exercise testing is not required for pre-exercise clearance in the majority of patients. [ABSTRACT FROM AUTHOR]

Background. To evaluate the safety and efficacy of moderate-to-high intensity aerobic training in breast cancer patients receiving neoadjuvant chemotherapy. Methods. Twenty patients with stage IIB-IIIC operable breast cancer were randomly assigned to receive doxorubicin plus cyclophosphamide (AC) or AC in combination with aerobic training (AC + AET) (n = 10/group) for 12 weeks. The AC+ AET group performed three supervised aerobic cycle ergometry sessions per week at 60%-100% of exercise capacity (VO2peak). Safety outcomes included exercise testing as well as treatment- and exercise training-related adverse events (AEs), whereas efficacy outcomes included cardiopulmonary function and patient-reported outcomes (PROs) as measured by a cardiopulmonary exercise test (CPET) and Functional Assessment of Cancer Therapy-Breast (FACT-B) scale. Results. Twelve non-significant ECG abnormalities and three non-life threatening events occurred during CPET procedures. One AE was reported during aerobic training. There were no significant between group differences for clinician-documented events (e.g. pain, nausea) or hematological parameters (p's > 0.05). Attendance and adherence rates to aerobic training were 82% and 66%, respectively. Intention-to-treat analysis indicated that VO2peak increased by 2.6 ± 3.5 ml/kg/min (+ 13.3%) in the AC + AET group and decreased by 1.5 ± 2.2 ml/kg/min (−8.6%) in the AC group (between group difference, p = 0.001). FACT-B increased 11.1 points in the AC + AET group compared to a 1.5 point decrease in the AC group (between group difference, p = 0.685). Conclusion. Moderate-to-high intensity aerobic training when conducted with one-on-one supervision is a safe adjunct therapy associated with improvements in cardiopulmonary function and select PROs during neoadjuvant chemotherapy. [ABSTRACT FROM AUTHOR]

Increased levels of physical activity are associated with many positive health outcomes in men including reproductive health as recently reported by Vieira et al. [[1]] in I The Aging Male i . Based upon the work of Vieira et al. [[1]], we wondered whether these exercise-related reductions in testosterone reached the clinical diagnostic threshold for androgen deficiency (AD) and occurred across the life span of runners. Nonetheless, outcomes point to the possible existence of greater occurrences of AD in men habitually engaged in endurance-based exercise training over a longer period of time (i.e., hence also typically older). [Extracted from the article]

This is the first report of the psychobiology of stress in BASE jumpers, one of the most dangerous forms of extreme sport. We tested the hypotheses that indicators of emotional style (temperament) predict salivary cortisol reactivity, whereas indicators of intentional goal-setting (persistence and character) predict salivary alpha-amylase reactivity during BASE jumping. Ninety-eight subjects completed the Temperament and Character Inventory (TCI) the day before the jump, and 77 also gave salivary samples at baseline, pre-jump on the bridge over the New River Gorge, and post-jump upon landing. Overall BASE jumpers are highly resilient individuals who are highly self-directed, persistent, and risk-taking, but they are heterogeneous in their motives and stress reactivity in the Hypothalamic-Pituitary-Adrenal (HPA) stress system (cortisol reactivity) and the sympathetic arousal system (alpha-amylase reactivity). Three classes of jumpers were identified using latent class analysis based on their personality profiles, prior jumping experience, and levels of cortisol and alpha-amylase at all three time points. “Masterful” jumpers (class 1) had a strong sense of self-directedness and mastery, extensive prior experience, and had little alpha-amylase reactivity and average cortisol reactivity. “Trustful” jumpers (class 2) were highly cooperative and trustful individuals who had little cortisol reactivity coincident with the social support they experienced prior to jumping. “Courageous” jumpers (class 3) were determined despite anxiety and inexperience, and they had high sympathetic reactivity but average cortisol activation. We conclude that trusting social attachment (Reward Dependence) and not jumping experience predicted low cortisol reactivity, whereas persistence (determination) and not jumping experience predicted high alpha-amylase reactivity. [ABSTRACT FROM AUTHOR]

Background: Energy availability (EA) and relative energy deficiency in sport (RED-S) are understudied in East African endurance athletes, both females (F) and males (M). This study assessed the metabolic hormonal profiles of such athletes relative to their EA status., Methods: Forty athletes (F=16, M=24) had their EA status, training, maximal oxygen uptake, and resting blood samples assessed using standard research practices. Subjects were stratified into two groups, high EA (HiEA) and low EA (LoEA) based on combined median value., Results: Cortisol (P=0.034) and insulin (P=0.044) were significantly elevated in the LoEA group, while growth hormone (P=0.045) was significantly suppressed; and, prolactin (P=0.078) trended towards suppression, respectively compared to the HiEA group. All other hormonal comparison were non-significant., Conclusions: Metabolic hormonal profiles of female and male African distance runners are affected by their EA status. Aspects of these alterations agree in part with published findings based upon White populations, although some differences exist and need further investigation.

We examined whether endurance training for a standard marathon (42.2 km) had a greater influence on male libido than more generalized endurance exercise training. We surveyed adult men (>1000) who regularly engaged in endurance running to evaluate exercise training histories-patterns and libido characteristics. Our participants were primarily recruited from North America and Europe. Results indicate men conducting marathon training had lower libido scores (p<0.05; ~20%, d=0.44) than those not doing such specific training. Factors most related to libido were: 1) the number of years of training, and 2) the proportion of high-intensity effort conducted in training (inverse relationships); regardless of whether marathon training was performed or not. Our survey approach did not allow us to determine the cause of the reduced libido, but we speculate it could relate to: 1) chronic physical fatigue from high volumes of exercise training, 2) behavioral accommodations in energy expenditure, or else 'Relative Energy Deficiency in Sport' (RED-S) syndrome, and/or 3) endocrinological adaptations as a result of the exercise training (i.e., low testosterone). From a practical perspective, we recommend couples attempting conception should inform their healthcare providers of the male partner's exercise habits concerning endurance running as this may be a factor relative to potential infertility.

Relative Energy Deficiency in Sport (RED-S) is predicated on the assumption that low energy availability (EA) induces deficiencies-dysfunction in multiple physiologic systems. However, research on RED-S and EA in male athletes is limited in comparison to women. The aim of this study is to investigate EA and the risk factors for RED-S, and their potential associations in non-elite male endurance athletes. Laboratory assessments for resting metabolic rate (RMR), bone mineral density (BMD), blood hormonal biomarkers and maximal aerobic capacity were conducted on 60 competitive, recreationally trained male endurance athletes (age=43.4±11.6 years [mean±SD], training=10.9±2.7 h/wk, 7.1±8.8 years). Participants provided 7-days of training logs and 4-days of diet records. Diet and training records were used to calculate EA. Correlations were used to examine associations between EA and RMR, BMD, stress fractures and reproductive, metabolic and bone biomarkers. Mean EA was 28.7±13.4 kcal/kg fat free mass (FFM), which categorized our sample as low EA (based upon published criterion, < 30 kcal/kg FFM) and at a high risk for RED-S. Hormonal and bone biomarkers were in normal clinical ranges, even though EA was low. The only interesting significant association was EA being negatively associated with total body BMD ( r = -0.360, P =0.005), opposite of expectations. On average our subjects displayed a state of low EA based upon the criterion which has been primarily developed from female-based research. Nonetheless, our participants displayed no major hormonal or bone health disturbances found in athletes diagnosed with RED-S. A value of < 30 kcal/kg FFM to diagnose low EA may not be appropriate for non-elite endurance trained men.

Background and Objectives: Relative energy deficiency in sport (RED-S) has been introduced as a broad-spectrum syndrome leading to possible dysfunction in numerous physiological systems, driven primarily by low energy availability (EA). Research in females has identified specific EA cut-points indicative of risk level for developing physiological and performance disturbances. Cut-points in males have yet to be evaluated. This study examined the prevalence of low EA in competitive (non-elite), recreationally trained (CRT) male endurance athletes. Materials and Methods : Subjects were 108 CRT (38.6 ± 13.8 y; 12.2 ± 5.4 h/wk training) male endurance athletes (runners, cyclists, triathletes) who completed a descriptive survey online via Qualtrics ® and returned 3 day diet and exercise training records. EA was calculated from returned surveys and training records. Resting metabolic rate (RMR) and lean body mass (LBM) were estimated from self-reported survey data. Prevalence of risk group was categorized based on the female cut-points: at risk (AR) ≤30 kcal/kg LBM, moderate risk (MR) = 30-45 kcal/kg LBM, or no risk (NR) ≥45 kcal/kg LBM. Results : In this sample, 47.2% ( n = 51) were classified as AR, 33.3% ( n = 36) as MR, and 19.4% ( n = 21) as NR for low EA. Cyclists had lower EA (26.9 ± 17.4 kcal/kg LBM, n = 45) than runners (34.6 ± 13.3 kcal/kg LBM, n = 55, p = 0.016) and all other sport categories (39.5 ± 19.1 kcal/kg LBM, n = 8, p = 0.037). Conclusions : The findings indicate this sample had a high prevalence of risk for low EA, at 47.2%. Only 19.4% of participants were at no risk, meaning ~80% of participants were at some degree of risk of experiencing low EA. Cyclists were at greater risk in this cohort of low EA, although why this occurred was unclear and is in need of further investigation. Future research should address whether the current female cut-points for low EA are appropriate for use in male populations., Competing Interests: The authors declare no conflict of interest.

The objective of this short review is to discuss how exercise training in men can result in changes in the reproductive system similar to those observed in women who develop athletic amenorrhea or suffer the Female Athlete Triad. Men chronically exposed to training for endurance sports exhibit persistently reduced basal free and total testosterone concentrations without concurrent luteinizing hormone elevations. These men are deemed to have the "Exercise-Hypogonadal Male Condition" (EHMC). Broadly, dysfunction in the hypothalamic-pituitary-gonadal regulatory axis is associated with either of these states. In women this effect on the axis is linked to the existence of a low energy availability (LEA) state, research in men relative to LEA is ongoing. The exact physiological mechanism inducing the reduction of testosterone in these men is currently unclear but is postulated to be a dysfunction within the hypothalamic-pituitary-gonadal regulatory axis. The potential exists for the reduced testosterone concentrations within EHMC men to be disruptive and detrimental to some anabolic-androgenic testosterone-dependent physiological processes. Findings, while limited, suggest spermatogenesis problems may exist in some cases; thus, infertility risk in such men is a critical concern. Present evidence suggests the EHMC condition is limited to men who have been persistently involved in chronic endurance exercise training for an extended period of time, and thus is not a highly prevalent occurrence. Nevertheless, it is critical that endocrinologist and fertility clinicians become more aware of the existence of EHMC as a potential problem-diagnosis in their male patients who exercise., Competing Interests: Conflicto de interés Los autores no declaran conflicto de intereses alguno.

Objective: The objective of this study was to profile over a 24 h period the prolactin responses of exercise-trained men on a day involving rest with no exercise in comparison to a day involving exercise training sessions., Methods: This is a quasi-experimental design study using repeated measures determination of 24 h prolactin responses in exercise-trained men (n = 16; age = 27.3± 3.3 years (mean ± standard deviation)). Blood samples were taken hourly over a 24 h period on a day involving two intensive exercise training sessions (ED), and on a separate control day (CD) with no exercise activity. The order of the ED and CD was randomized. Physical activity and diet were controlled and replicated for the ED and CD. Blood specimens were handled, prepared and analyzed utilizing appropriate standard clinical practices. The data were analyzed with the Friedman analysis of variance and Nemenyi post hoc statistical procedure for repeated measures., Results: On the CD, prolactin displayed a typical circadian rhythm with daytime values of the hormone being less than the nocturnal rise once sleep had begun (p < 0.05; 16:00-20:00 h > all other times). On the ED, prolactin responses were noticeably different from those of the CD. The morning and afternoon exercise sessions included significant increases in prolactin immediately at the end of the exercise sessions, being greater than corresponding CD time points (p < 0.01; 01:00 h and 10:00 h); also for the second hour (2 h) following the morning exercise session. On the ED there was a displayed circadian nocturnal response in the hormone with 16:00-24:00 h being elevated above the all nonexercise effected values for that specific day (p < 0.01). Finally, the ED nocturnal elevation for prolactin for 16:00-24:00 h was significantly greater than the same respective hours on the CD (p < 0.05)., Conclusion: Findings clearly demonstrated that nocturnal prolactin responses are augmented in exercise-trained men on days when they perform exercise. The mechanisms inducing this adaptive response are unclear but warrant further investigation.

The endocrine system has profound regulatory effects within the human body and thus the ability to control and maintain appropriate function within many physiological systems (i.e., homeostasis). The hormones associated with the endocrine system utilize autocrine, paracrine, or endocrine actions on the cells of their target tissues within these physiologic systems to adjust homeostasis. The introduction of exercise as a stressor to disrupt homeostasis can greatly amplify and impact the actions of these hormones. To that end, the endocrine response to an acute exercise session occurs in a progression of phases with the magnitude of the response being relative to the exercise work intensity or volume. Various physiologic mechanisms are considered responsible for these responses, although not all are completely understood or elucidated. Chronic exercise training does not eliminate the acute exercise response but may attenuate the overall effect of the responsiveness as the body adapts in a positive fashion to the training stimulus. Regrettably, an excessive intensity and/or volume of training may lead to maladaptation and is associated with inappropriate endocrine hormonal responses. The mechanisms leading to a deleterious maladaptive state are not well understood and require additional research for elucidation., (© 2015 Elsevier Inc. All rights reserved.)

Investigative studies point to participation in exercise training as having significant detrimental effects upon reproductive hormonal profiles in men. Specifically, men chronically exposed to training for endurance sports exhibit persistently reduced basal (resting-state) free and total testosterone concentrations without concurrent LH elevations. Men displaying these symptoms have been deemed to exhibit the "Exercise-Hypogonadal Male Condition" (EHMC). The exact physiological mechanism inducing the reduction of testosterone in these men is currently unclear, but is postulated to be a dysfunction within the hypothalamic-pituitary-gonadal regulatory axis. The potential exists for the reduced testosterone concentrations within EHMC men to be disruptive and detrimental to some anabolic-androgenic testosterone-dependent physiological processes. Findings, while limited, suggest spermatogenesis problems may exist in some cases; thus, infertility risk in such men is a critical concern. Present evidence suggests the EHMC condition is limited to men who have been persistently involved in chronic endurance exercise training for an extended period of time, and thus is not a highly prevalent occurrence. Nevertheless, it is critical that endocrinologist and fertility clinicians become more aware of the existence of EHMC as a potential problem-diagnosis in their male patients who exercise.