Training protocols
Participants completed 36 sessions in the HIFT program that lasted up to 60 min per session. The CrossFit program was used and HIFT sessions were led by a CrossFit trainer where the first two sessions were structured as an introduction to common movements used in HIFT (e.g., squats, deadlift, press, jerks, barbell, dumbbell, and medicine ball cleans, pull-ups, kettlebell swings, among others) with no additional workouts on days 1 and 2. Starting on day 3, each HIFT class consisted of 10–15 min of stretching and warm up, 10–20 min of instruction and practicing techniques and movements, and 5–30 min for the workout of the day that was performed at vigorous intensity and relative individual levels of ability and fitness. Workout modalities included aerobic (e.g., running, jumping rope), body weight (e.g., pull-ups, squats), and weightlifting (e.g., front squats, kettlebell swings) exercises that were constantly varied using the CrossFit training template (