ABSTRACT
Objective To explore the effect of low-level laser therapy (LLLT)applied to the quadriceps muscle on the recovery of exhausting-cycling-exercise-induced fatigue.Methods According to a randomised,double-blind and crossover design,16 healthy male students were randomly assigned to an LLLT-1,LLLT-3,LLLT-5 and a placebo group,and received LLLT for 300 s at the dosage of 0.06 J· cm-2,0.18 J·cm-2,0.3 J·cm-2 and 0 to the bilateral rectus femoris after the exhausting-cycling-exercise-induced fatigue.The blood lactate(BL),heart rate(HR),rated perceived exertion(RPE)and visual analogue scale(VAS)were assessed before the exercise,immediately after exercise,10 and 20 min after exercise,as well as immediately after the first Wingate(WG)test,5 and 30 min after the WG test.Meanwhile,the second WG test was performed 40 min after the first WG test.Results The average HR value of LLLT-1 group was significantly lower than the placebo group at 10 min after exercise(P＜ 0.05)and immediately after the WG test(P＜0.01),while that of LLLT-3 and LLLT-5 groups was significantly lower than the placebo group immediately and 5 min after the WG test(P＜0.01).Compared to the placebo group,the average BL of LLLT-1,LLLT-3 and LLLT-5 groups was significantly lower 10 min after exercise(P＜0.05 for all)and that of LLLT-5 group was also significantly lower 30 min after the first WG test(P＜0.05).However,the average blood glucose of LLLT-5 group was significantly higher than the placebo group right after the first WG test(P＜0.05).Moreover,significant increase was observed in the mean(P=0.002)and peak power(P=0.006)at the second WG test and the mean(P=0.048) power at the first WG test of LLLT-3 group,compared to the placebo group.Conclusion LLLT applied to quadriceps muscles after exhausting exercise may enhance recovery,and LLLT at the dose of 0.18 J·cm-2 is of the best effect.
ABSTRACT
Objective:To observe the changes of 5-HT1B and D1DR expression in nucleus of SNr/GPi-VL-SMA pathway in pre and post-exhaustive exercise,and investigate the central mechanism of SNr/GPi-VL-SMA pathway modulating the occurrence and development of exercise-induced fatigue.Method:Twenty-four male Wistar rats were randomly divided into control group (CG),immediately after exhaustion group (EG),and 90min after recovery group (RG),each consists of 8 rats.The expression level of 5-HT1B and D1DR receptors in each group were observed with the immunohistochemistry technique.Result:Compared with CG,the positive cell area/scanning area value (R value) and the average optical density value (AOD value) of 5-HT1B receptor in SNr and GPi of the EG and RG rats both decreased significantly (P ＜ 0.05),while the R value and AOD value of D1DR both increased significantly(P＜ 0.05).The R value and AOD value of 5-HT1B receptor in VL of EG and RG rats increased significantly(P＜0.05,P＜0.01).In SMA,the R value and AOD value of 5-HT1B receptor of EG and RG rats increased significantly (P＜ 0.05),while,the R value and AOD value of D1DR receptor decreased significantly (P ＜ 0.05).Conclusion:Changes of 5-HT1B receptor and D1DR receptor expression in the nuclei of ‘SNr/GPi-VL-SMA'pathway caused the changes of the neurotransmitters release,thus affecting the excitability of the electrical activity of neurons,this might be one of the important ways for ‘SNr/GPi-VL-SMA'pathway modulating the exercise-induced fatigue and exercise performance.