Final answer:
a) Caffeine is the substance that may improve the performance of sprinters and weightlifters, boosting endurance, reducing fatigue, and increasing power output during exercise.a) Caffeine
Step-by-step explanation:
Among the substances listed, caffeine has been scientifically proven to improve the performance of sprinters and weight lifters. Caffeine is an ergogenic aid that enhances athletic performance both in aerobic (like endurance sports) and anaerobic conditions. Moderate consumption prior to exercise has been shown to increase fat oxidation and reduce perceived exertion, which can lead to improved sprint performance, higher power output, and enhanced muscle endurance. It should be noted that while caffeine may assist sprinters and weightlifters, the benefits might be more pronounced in individuals who do not regularly consume caffeine.
Caffeine is a substance that may improve the performance of sprinters and weightlifters according to scientific evidence. Moderate doses of caffeine can improve sprint performance, cycling and running time trial performance, endurance, and cycling power output. Caffeine increases basal metabolic rate and fat oxidation in adults. It is considered an ergogenic aid in both aerobic and anaerobic conditions.