All training was conducted with one‐on‐one supervision from trained research personnel who were experienced with our HIIT protocol and were closely supervised by study investigators to ensure intervention fidelity. Participants chose the mode of exercise (eg, cycling or walking). Cycling was encouraged, but if the participant did not feel as though they were able to cycle or preferred not to, the treadmill was supported. Each training session included a 3‐ to 5‐minute warm‐up of low‐intensity cycling or walking (depending on the chosen mode) followed by 10 repetitions of 1 minute of exercise at a given participant’s 90% VO2peak with 1‐minute rest periods. A complete rest period was used rather than low‐ to moderate‐intensity exercise to maximize effort on the work bout (and minimize additional joint stress) and maximize metabolite accumulation to support greater adaptations. The training occurred twice weekly for 12 weeks, with at least 24 hours in between training sessions, similar to prior protocols (41 (link)). Heart rate was monitored and recorded using chest strap heart rate monitors (Polar FT1, Polar USA). Participants were also instructed to keep outside activity consistent with what they were doing prior to study enrollment.