Whey protein hydrolysate enhances exercise endurance, regulates energy metabolism, and attenuates muscle damage in exercise mice

This study aimed to explore the effects of whey protein concentrate (WPC) and whey protein hydrolysate (WPH) on energy metabolism, muscle injury, and underlying mechanisms in exercise mice by utilizing the swimming 40 min test and exhaustive swimming test, respectively. Results showed that WPH mainly consisted of low molecular weight peptides (359–2266 Da), and 78% of the peptides contained branched chain amino acids. In the swimming 40 min test, WPH possessed better influences than WPC in delaying glycogens consumption, promoting lactate and urea nitrogen elimination, and relieving oxidative stress in mice. Additionally, both WPC and WPH attenuated muscle damage via inhibiting inflammatory response. In the exhaustive swimming test, WPH significantly prolonged swimming time, which was 1.5- and 1.4-fold longer compared with control and WPC groups, respectively. Moreover, WPC and WPH promoted the recovery of muscle damage within 30 min of rest, which might be related to the activation of protein synthesis pathway (mammalian target of rapamycin, mTOR). Notably, compared with WPC, WPH showed better abilities in increasing the contents of glucose and liver glycogen and inhibiting inflammatory pathways, although its swimming time was longer. Taken together, WPH can be an effective ingredient for the prevention and elimination of exercise-induced fatigue.