The present study aimed to investigate the effects of polysaccharides from Maca (MCP) on oxidative damage induced by exhaustive swimming exercise using rat models. The rats were divided into five groups: sedentary control group (SC), exercise control group (EC), exercise+50 mg/kg MCP treated group (EM-50), exercise+100 mg/kg MCP treated group (EM-100), exercise+200 mg/kg MCP treated group (EM-200). SC and EC groups received distilled water while three MCP treated groups received different doses of MCP (50, 100 and 200 mg/kg bw) by oral gavage once daily. After 28 days, the rats were forced to swim in a plastic tank until being exhausted, and the following biochemical parameters of oxidative damage were measured: aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG). In all MCP treated groups, serum LDH and CK levels were significantly lower than those in the EC group, whereas in the E-100 and M-200 groups, a decrease was also seen for serum AST levels. Furthermore, the GSSG and 8-OHdG levels in the E-100 and M-200 groups, as well as the MDA levels in all MCP treated groups were significantly lower. In contrast, all MCP treated groups exhibited significantly higher levels of SOD, CAT, GPx, GSH and GSH/GSSG ratio in muscle. The GR levels in muscle were also significantly increased in the E-100 and M-200 groups. These results demonstrate that MCP might have protective effects on exhaustive exerciseinduced oxidative damage.