| Objective: To observe the effects of acute and chronic supplement of beet root juice on the physical function and performance of track and field sprinters,and to provide theoretical basis for sports practice by exploring the nutritional effect of beet root juice supplement.Methods: A randomized,single-blind,placebo-controlled study was conducted on 24 male undergraduates from the track and field special class of the Guangzhou Sport University.In the acute and chronic phase,the placebo group and the supplement group were supplemented with brown sugar water placebo and beet root juice supplement respectively.A 7-day washout period was arranged in the middle of the replenishment period.Beet root juice was tested four times before and after acute and chronic supplement.After arriving at the laboratory,the athletes sit for 10 minutes and measure systolic blood pressure,diastolic blood pressure,heart rate and blood oxygen saturation.5ml venous blood was collected at rest to separate serum NO,blood lactate and serum creatine kinase.The muscle circumference of upper arm was measured,and the grip strength and reaction time were tested.The peak power,average power,power decline rate,heart rate,blood oxygen saturation and other related indexes were recorded.In the aerobic work test,RPE,heart rate,blood oxygen saturation and the time from maximum working ability to exhaustion were recorded after each level of load,and blood lactic acid was measured at 3 minutes after exercise to obtain the highest blood lactic acid value.Spss22.0 software package was used to analyze the data.Paired sample t-test was used for intra group comparison before and after supplement,and independent sample t-test was used for inter group comparison,P<0.05 was significant,P<0.01 was very significant.Results: 1.Compared with before supplement,the concentration of no in the acute supplement group was significantly increased(P<0.05),and the reaction time was significantly decreased(P<0.05);systolic blood pressure,diastolic blood pressure,heart rate,blood oxygen saturation,serum creatine kinase,blood lactic acid,upper arm muscle circumference,grip strength,peak power,average power,power decline rate,heart rate,blood oxygen saturation after exercise,increased load There was no significant difference in RPE,heart rate,oxygen saturation,exhausted heart rate,blood lactic acid and exhausted time(P>0.05).2.Compared with before supplement,systolic blood pressure,diastolic blood pressure,no concentration,right hand grip strength,reaction time,peak power,average power and power decline rate in chronic supplement group were significantly lower(P<0.05),higher(P<0.01),higher(P<0.05)and higher(P<0.05)There was no significant difference in heart rate,blood oxygen saturation,serum creatine kinase,blood lactate,upper arm muscle circumference,left hand grip strength,heart rate and blood oxygen saturation after anaerobic exercise,heart rate,RPE,blood oxygen saturation and exhausted heart rate after incremental load exercise(P>0.05).3.Compared with the acute supplement group,the systolic and diastolic blood pressure of the chronic supplement group were significantly decreased(P<0.05),the concentration of no was significantly increased(P<0.01),the grip strength of the right hand was significantly increased(P<0.05),the reaction time was significantly decreased(P<0.05),the peak power and average power were significantly increased(P<0.05),the power decline rate was significantly decreased(P<0.05),and the power increased gradually Blood lactic acid and exhaustion time increased significantly after exercise(P<0.05).There were no significant differences in heart rate,blood oxygen saturation,serum creatine kinase,blood lactic acid,upper arm muscle circumference,left hand grip strength,heart rate and blood oxygen saturation after anaerobic exercise,RPE,heart rate,blood oxygen saturation and exhausted heart rate after incremental load exercise(P>0.05).Conclusion:1.Acute supplementation of beetroot juice can improve blood nitric oxide level and agility of sprinters.2.Chronic supplementation of beetroot juice can improve the body function and performance of sprinters,especially on blood pressure,agility,strength,anaerobic ability and aerobic ability.3.Chronic supplementation of beetroot juice had better effects on improving sprinters’ physical function and athletic performance than acute supplementation. |
