Exercise-Induced Salivary Hormone Responses to High-Intensity, Self-Paced Running

Salivary hormone concentrations and technical-tactical performance indicators in beach volleyball: Preliminary evidence

The present study aimed to investigate (i) differences in salivary testosterone and cortisol concentrations before, during, and after simulated beach volleyball match, depending on match outcome (winning vs. losing); (ii) the relationship between technical-tactical performance indicators in beach volleyball and salivary hormonal concentrations (i.e., testosterone, cortisol). We hypothesized (i) salivary testosterone concentrations would be greater in winners and salivary cortisol would be lower; (ii) testosterone would associate with positive technical-tactical performance and cortisol would associate with negative technical-tactical performance. Sixteen athletes participated in the study and were grouped according to the result of a simulated game (winners: n = 8; losers: n = 8). Salivary hormone concentration of testosterone and cortisol were measured by enzyme-linked immunosorbent assay (pre-match, post first set, and post-match), and the coefficient of performance and efficiency were used as technical-tactical performance indicators. Regarding testosterone, there was a large effect size for match outcome after the first set (i.e., Winner vs. Losers) and a moderate effect size for the time in winners (pre-match vs. post-match). Regarding cortisol, there was a moderate effect size of time in losers only (pre-match vs. post-match). Moreover, cortisol pre-match was negatively correlated with the offensive performance (attack performance coefficient: r = −0.541; p = 0.030; attack efficiency: r = −0.568; p = 0.022). In conclusion, the effect of match outcome on testosterone and cortisol levels was moderate in winners and losers, respectively. Moreover, resting cortisol concentration appears to be related to a diminished attack technical-tactical performance. However, larger confirmatory studies are required to confirm these data to corroborate winning increases testosterone levels and/or reduces cortisol in a sporting setting.

Differential Metabolites and Metabolic Pathways Involved in Aerobic Exercise Improvement of Chronic Fatigue Symptoms in Adolescents Based on Gas Chromatography-Mass Spectrometry

Studies have found that the prevalence of chronic fatigue syndrome (CFS) in adolescents has continued to increase over the years, affecting learning and physical health. High school is a critical stage for adolescents to grow and mature. There are inadequate detection and rehabilitation methods for CFS due to an insufficient understanding of the physiological mechanisms of CFS. The purpose of this study was to evaluate the effect and metabolic mechanisms of an aerobic running intervention program for high school students with CFS. Forty-six male high school students with CFS were randomly assigned to the exercise intervention group (EI) and control group (CFS). Twenty-four age- and sex-matched healthy male students were recruited as healthy controls (HCs). The EI group received the aerobic intervention for 12 weeks, three times a week, in 45-min sessions; the CFS group maintained their daily routines as normal. The outcome measures included fatigue symptoms and oxidation levels. Keratin was extracted from the nails of all participants, and the oxidation level was assessed by measuring the content of 3-Nitrotyrosine (3-NT) in the keratin by ultraviolet spectrophotometry. All participants’ morning urine was collected to analyze urinary differential metabolites by the GC-MS technique before and after the intervention, and MetaboAnalyst 5.0 was used for pathway analysis. Compared with before the intervention, the fatigue score and 3-NT level in the EI group were significantly decreased after the intervention. The CFS group was screened for 20 differential metabolites involving the disruption of six metabolic pathways, including arginine biosynthesis, glycerolipid metabolism, pentose phosphate pathway, purine metabolism, β-alanine metabolism, and arginine and proline metabolism. After the intervention, 21 differential metabolites were screened, involved in alterations in three metabolic pathways: beta-alanine metabolism, pentose phosphate metabolism, and arginine and proline metabolism. Aerobic exercise was found to lessen fatigue symptoms and oxidative levels in students with CFS, which may be related to the regulation of putrescine (arginine and proline metabolism), 6-Phospho-D-Gluconate (starch and sucrose metabolism pathway), and Pentose (phosphate metabolism pathway).

Polymorphonuclear leucocyte phagocytic function, γδ T-lymphocytes and testosterone as separate stress-responsive markers of prolonged, high-intensity training programs

Excessive exercise with limited recovery may lead to detrimental states of overreaching or the overtraining syndrome. Chronic maladaptation in endocrine and immune mechanisms occur with the incidence of these states. Exercise-induced cortisol and testosterone responses have been proposed as biomarkers of overreaching, with blunted responses following intensified-training periods. Yet, limited information on the effects of overreaching in immunity is available. Healthy individuals completed a 30-min running protocol (the RPE_TP) before and after a 12-day intensified-training period. Blood and saliva were collected before, after and 30min after RPE_TP at pre-training and post-training. Plasma and salivary cortisol and testosterone, leucocyte proliferation and polymorphonuclear leucocyte phagocytic activity were examined. Plasma and salivary cortisol were acutely unaffected pre-training (-14% and 0%, p ​> ​0.05) and post-training (-14% and +46%, p ​> ​0.05). Comparing pre-training with post-training, blunted responses were observed in plasma testosterone (43%-19%, p ​< ​0.05) and salivary testosterone (55%-24%, p ​> ​0.05). No acute or resting changes in total leucocyte counts or most leucocyte subsets occurred pre-training or post-training. Yet, a 194% acute elevation in γδ T-lymphocyte number occurred pre-training (p ​< ​0.05), and average resting concentrations were 174% higher post-training. Baseline phagocytic activity was 47% lower post-training (p ​< ​0.05). Intensified training was detrimental, significantly reducing phagocytic activity. Testosterone blunted post-training, indicating an excessive training-related hypothalamic-pituitary gonadal dysfunction. The γδ T-lymphocytes sensitivity to exercise was noted, rendering it as a potential stress-responsive cellular marker. The usefulness of the RPE_TP to track the onset of overreaching is proposed.