Effect of a nutritional formula on enhancing endurance of heavy load exercise

To develop a nutritional formula on enhancing the endurance of heavy load exercise, and evaluate its efficacy comprehensively.

Sixty C57BL/6J male mice were randomly divided into control group (CON group) and low-, medium- and high-dose nutritional formula groups (LDF, MDF and HDF groups), with 15 mice in each group. Each group received intervention with nutritional formula at corresponding dose for 2 weeks, and underwent adaptive training and heavy load exercise in the 1st and 2nd weeks, respectively. Exhaustion exercise time, skeletal muscle antioxidant indicators (SOD, MDA, PC and GSH), fatigue related indicators (serum URA, LDH and LA), muscle glycogen, and serum exercise injury related indicators (ALT, AST, CK and CK-MB) were measured and detected in the mice, and comprehensive evaluation was conducted according to relevant evaluation standards.

The LDF group, MDF group and HDF group had significantly prolonged running exhaustion time than the CON group (P<0.05), with the HDF group showing the greatest improvement (P<0.05). Compared with the CON group, the activities of SOD and GSH in the skeletal muscles were significantly increased (P<0.05), while the levels of MDA and PC in skeletal muscles were obviously decreased in the 3 doses of nutritional formula groups (P<0.05). PAS staining of the skeletal muscles displayed that the glycogen content was significantly increased in the MDF group and the HDF group than the CON group (P<0.05), and the highest increase was observed in the HDF group (P<0.05). Biochemical test revealed that the levels of LDH, LA, ALT, AST, CK, and CK-MB were remarkably lower in the 3 doses of nutritional formula groups than the CON group (P<0.05).

The nutritional formula can significantly improve the endurance and skeletal muscle antioxidant capacity in mice under heavy load exercise, and has anti-fatigue and -injury protection effects. This nutritional formula can be used to support physical fitness during heavy load endurance exercise.