Exhaustive Exercise Protocol
BRUCE
Based on previous studies, the exhaustive Bruce aerobic test was executed on a treadmill. After 10 minutes of general warm-up, the subjects started the protocols on the treadmill (10 Min, 4 km/h, 0%). The test consisted of 7 steps of 3 minutes, starting with a 10% slope and 1.7 mph speed. The slope of the device increased by 2%, and the speed increased by 1.7 mph every 3 minutes until the subjects were no longer able to continue their activities and expressed complete exhaustion. Finally, 5 minutes of cooling down at a 4 km/h and a zero slope were performed. While running, the Borg scale Rated Perceived Exertion (RPE) was used (3). Both Exp and C performed the exercise program twice, before starting the Vit D supplementation (or placebo) and after six weeks of intervention (Overview of the study design