A meta-analysis examining 31 randomized crossover trials has quantified the glycogen-sparing effect of carbohydrate supplementation during prolonged endurance exercise at approximately 9%, a statistically significant but modest reduction in muscle fuel depletion. The research, published in the Journal of Applied Physiology and led by Dr. Jacob A. Rothschild, analyzed predominantly cycling and running studies with exercise durations around 100 minutes. However, the data reveals considerable individual variability: despite the aggregate finding, 46 of 48 individual study comparisons failed to demonstrate statistically significant glycogen sparing. This discrepancy highlights that carbohydrate’s performance benefits extend well beyond fuel conservation. Current evidence suggests carbohydrate supplementation operates through multiple performance-enhancement pathways, making glycogen sparing just one component of its ergogenic profile in endurance athletics. Read the full article on GMJ Newsroom.
Was this article helpful?
