Data from the mouse study indicated that two weeks of supplementation with glutathione prevented the decrease in intermuscular pH, which typically occurs as lactic acid builds up. In sedentary mice, mitochondria levels increased after glutathione supplementation, compared with sedentary control animals.
Two weeks of supplementation in men was found to decrease exercise-induced fatigue, compared to placebo, reported scientists from Kyoto Prefectural University and Kohjin Life Sciences Company.
“To the best of our knowledge, the present study is the first to demonstrate that glutathione supplementation improves aerobic metabolism in skeletal muscle, leading to reduced exercise-induced muscle fatigue,” they wrote in the Journal of the International Society of Sports Nutrition.
The scientists divided mice into four groups: Two groups were sedentary with or without glutathione supplementation, and two groups underwent exercise programs with or without glutathione for two weeks. Results showed that glutathione prevented the decrease in pH levels in the muscles, compared to control.
In addition, glutathione supplementation in the sedentary animals was associated with significant increases in mitochondrial DNA levels and levels of a marker called peroxisome proliferator-activated receptor-gamme coactivator-1alpha (PGC-1alpha) of 53% and 25%, respectively. PGC-1alpha is reported to play a role in the production of mitochondria in skeletal muscle.
For the human trial, eight health men were recruited to participate in the double-blind, cross-over study. The men were assigned to undergo exercise tests with or without two weeks of one gram per day of glutathione supplementation.
Results showed that glutathione supplementation was again associated with suppression in lactate levels, while fatigue measures were also significantly decreased, compared with the placebo group.
“These observations suggest that glutathione induces aerobic metabolism and improves an acidic environment in skeletal muscle during exercise by elevating PGC-1alpha, which would prevent exercise-induced fatigue,” concluded the researchers.
Source: Journal of the International Society of Sports Nutrition
2015, 12:7, doi: 10.1186/s12970-015-0067-x
“Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism”
Authors: Aoi W, Ogaya Y, Takami M, Konishi T, Sauchi Y, Park EY, Wada S, Sato K et al.