HIIT Increases Muscle Power and Free Testosterone in Master Athletes

High-intensity interval training (HIIT) improves peak power output (PPO) in sedentary men, but has not been examined in master endurance athletes.

This study applied a six-week low-volume HIIT program to determine: 1) if it would improve PPO in master athletes, and 2) if any change in PPO would be associated with changes in the steroid hormone testosterone.

Seventeen male master athletes (60 ± 5 years old) completed the intervention, which included nine HIIT sessions over six weeks. HIIT sessions involved six 30-s sprints at 40% PPO, interspersed with 3 minutes of active recovery. Absolute PPO (799 ± 205 W vs. 865 ± 211 W) and relative PPO (10.2 ± 2.0 W/kg vs. 11.0 ± 2.2 W/kg) increased from pre- to post-HIIT, respectively (P < 0.001, Cohen's d = 0.32-0.38). No significant change was observed for total testosterone (15.2 ± 4.2 nmol/L to 16.4 ± 3.3 nmol/L (P = 0.061, Cohen's d = 0.32)), while a small increase in free testosterone occurred after HIIT (7.0 ± 1.2 ng/dL vs. 7.5 ± 1.1 ng/dL pre- and post-HIIT (P = 0.050, Cohen's d = 0.40)).

Six weeks of HIIT improves PPO in master athletes and increases free testosterone. Taken together, these data indicate that there is a place for carefully scheduled HIIT periods in master athlete regimes.

Endocr Connect. 2017 Oct;6(7):430-436. doi: 10.1530/EC-17-0159.

This content is part of Clínica Revitalize's commitment to translating science into accessible clinical practice — without losing rigor or depth.