The effects of four weeks aerobic training on saliva cortisol and testosterone in young healthy persons.

[Purpose] The purpose of this study was to evaluate the effect of 4 weeks moderate aerobic exercise on outcome measures of saliva stress hormones and lactate levels in healthy adult volunteers. [Subjects and Methods] Sixteen healthy students with an age range of 15-25 years participated in this study. The participants performed an exercise test of moderate intensity for 4 weeks, three times per week. The exercise was treadmill walking. Saliva concentrations of cortisol, testosterone and lactate dehydrogenase (LDH) were measured before and after the 4 weeks of moderate aerobic training using immunoassay techniques. [Results] After 4 weeks of exercise, there were significant increases in cortisol, free testosterone levels, and LDH activity along with a significant decrease in the ratios between testosterone and cortisol levels. No significant correlations were found among the studied parameters in the resting stage, a result which supports the positive effect of exercise on stress hormones following 4 weeks of training. [Conclusion] The results suggest that four weeks exercise of moderate intensity significantly affects the salivary stress hormones of young healthy volunteers. The data support the importance of salivary stress hormones as potential biological markers especially for older ages. However, more research is required to validate these biological markers which determine the host response to physical activity.

Effect of Moderate Aerobic Training on Bone Metabolism Indices among Adult Humans.

OBJECTIVE: This study assessed the osteogenic effect (T-Score) and changes in bone markers in healthy subjects by 12-weeks of aerobic training. METHODS: Total 65 healthy subjects (36 males, 29 females), their age ranged between 30 and 60 years with normal body mass index, were recruited to participate in this study and they were selected among healthy subjects who do not have any metabolic disorders and were not receiving any medication that could affect the bone turnover. Standardized physical examination and collection of serum samples were performed at base line and after 12 weeks of moderate aerobic training to measure bone formation markers (osteocalcin (OC) and bone specific alkaline Phosphatase (BAP) and bone resorption marker Deoxypyridinoline (DPD), and serum calcium. Each subject participated in exercise training program for 12 weeks, three times per week. RESULTS: The results showed that the 12 weeks of moderate aerobic training produced a significant improvement in all bone metabolism indices including Serum bone-specific alkaline phosphatase, serum osteocalcin, serum free Calcium and bone mineral density among all subjects. Conclusion : Moderate intensity of aerobic training exerts significant positive effects on bone formation marker and bone density associated with a significant decrease in the rate of bone resorption that could assist in preventing or decelerating osteoporosis.