Increase in testosterone and cortisol one week after repeated exercise in a cold environment

Area of Science:

• Exercise physiology
• Environmental physiology
• Endocrinology

Background:

• Cold exposure research often focuses on post-exercise effects.
• Understanding physiological responses to exercise in cold is crucial for athletes.
• Limited data exists on delayed hormonal and body composition changes after cold-environment training.

Purpose of the Study:

• To investigate the effects of gradually increasing cold exposure and physical exercise on steroid levels, body composition, and biochemical markers in male athletes.
• To assess immediate and delayed physiological responses following a 5-day cold-environment training period.
• To analyze changes in hormones, inflammatory markers, and antioxidant activity after cold exposure and recovery.

Main Methods:

• Healthy male athletes (n=12) underwent 5 days of outdoor physical training in 2°C-3°C with increasing intensity.
• Blood samples and bioelectrical impedance measurements were taken before, after the 5-day experiment, and after 7 days of recovery.
• Analysis included circulating levels of testosterone, cortisol, androstenedione, dehydroepiandrosterone sulphate, 17-hydroxyprogesterone, calcifediol, interleukin-6, C-reactive protein, and erythrocyte superoxide dismutase activity.

Main Results:

• A significant delayed increase in total plasma testosterone (56%) and cortisol (54%) was observed after 7 days of recovery, with no immediate changes post-exercise.
• Bioelectrical impedance analysis revealed a decreased waist-to-hip ratio post-experiment, which normalized after 7 days.
• No significant changes were found in Interleukin-6, C-reactive protein, or erythrocyte superoxide dismutase levels.

Conclusions:

• A 5-day exercise period in a cold environment induces delayed adaptive physiological changes.
• Significant increases in steroid hormones, including testosterone and cortisol, occur up to 7 days post-exposure.
• The testosterone/cortisol ratio remained unchanged, suggesting a balanced hormonal response to cold-environment training.