Abstract
The aim of the study was to investigate the effect of a flavonoid-rich fresh fruit juice on cardiovascular, oxidative stress, and biochemical parameters during the yo-yo intermittent recovery test (YYIRT). Twenty-two healthy males subjects participated in this study divided into two groups: An experimental group (EG: n=11) who consumed the antioxidant supplement and a control group (CG: n=11). All participants performed two test sessions at 07:00hr before and after 2weeks of supplementation with Opuntia ficus-indica juice. Blood samples were taken before (P1) and immediately (P2) after the YYIRT. Our results showed that following the 2,2-diphenyl-1- picrylhydrazyl (DPPH.) test, the Opuntia ficus-indica juice has an antioxidant capacity for capturing free radicals (p<.05) and reducing oxidative stress related to exercise. Concerning biochemical and cardiovascular parameters, our results showed a significant increase on total cholesterol (TC) (p<.01), triglycerides (TG) (p<.05), high-density lipoprotein (HDL) (p<.01), low-density lipoprotein (LDL) (p<.01), creatine kinase (CK) (p<.01), lactate deshydrogenase (LDH) (p<.01), glucose (GLC) (p<.01), systolic (SBP), and diastolic blood pressure (DBP) (p<.01) immediately after exercise. However, TC (p<.05), TG (p<.05) and LDL (p<.05), the maximal heart rate (HRmax), the CK (p<.05), and LDH (p<.01) as well as the malondialdehyde (MDA) (p<.01) demonstrated a significant decrease after supplementation of Opuntia ficus-indica juice before and immediately after YYIRT. However, no significant effect on HDL (p>.05), GLC (p>.05) levels nor the SBP and DBP (p>.05) was observed after supplementation with Opuntia ficus-indica juice. The supplementation leads to an improvement on YYIRT performance (The total distance covered during the YYIRT,VO2max, VMA) and the rating of perceived exertion (RPE). Opuntia ficus-indica juice has a potent antioxidant activity that reduces total and LDL-cholesterol with only a moderate lowering of HDL-cholesterol and oxidative stress. Moreover, supplementation decreases muscle damage caused by the endurance exercise.