Can a supplement boost athletic performance in already fit young people?

This study looked at whether a supplement called MIB-626 (a form of vitamin B3) could improve physical fitness, muscle energy, and brain function in healthy, highly active adults aged 19 to 40. Participants took either the supplement or a placebo twice daily for 10 weeks, with some also doing a high-intensity exercise program. The goal was to see if the supplement, alone or with exercise, could boost aerobic capacity and endurance beyond what exercise alone provides.