Objective: To study the effects of chitosan oligosaccharide(CO) on anti-exercise fatigue and exercise-induced immunosuppression. Method: To establish the model of high-intensity endurance training

55 7-week-old male SPF Wistar rats were randomly divided into 5 groups

with 10 in each group (the rats that did not meet the requirements were removed) : clam group ( C group)

exercise group ( E group)

exercise + ig low-dose

middle-dose and high-dose chitosan oligosaccharide group ( CO+E-L group

CO+E-M group

CO+E-H group).Gavage was performed by using professional devices once a day.The rats in CO groups were gavaged CO 100

200

600 mg ·kg-1 with ig volume of 5 mL ·kg-1 respectively. Rats in other groups were given saline of the same volume.After 42 days of exhaustive swimming training

measuring related indicators. Result: Swimming time in CO+E groups were significantly longer than that in E group ( P< 0.01).There were no difference between C and E groups.Serum superoxide dismutase(SOD) and interleukin-10(IL-10) in E group were significantly lower than C group ( P< 0.01)

at the same time

those in CO+E groups were all higher than E groups (P< 0.05

P< 0.01).Serum malondialdehyde(MDA)

nuclear factor-kappa B(NF-κB)

interleukin-6(IL-6)

tumor necrosis factor-α(TNF-α) and spleen Toll like receptor 4(TLR4) expression ratio in E group were all significantly higher than C group ( P< 0. 01)

those in CO+E groups were all lower than that in E group (P< 0.05

P< 0.01). Conclusion: The supplement of CO can effectively relieve the imbalance of internal environment caused by excessive training

avoid the occurrence and development of exercise fatigue and exercise immunosuppression and CO+E-H group have a significant effect.