场地短距离自行车大强度骑行中的疲劳定量分析

目的：对场地自行车不同传动比下大强度骑行过程中功率、频率变化进行测评，分析传统疲劳指数、频率指数和净疲劳指数在疲劳评价中的应用价值。方法：10名男子短距离自行车运动员分别使用50：12和50：13两种传动比进行两次200m俯冲骑行测试，使用SRM自行车专用功率记录仪采集骑行全程的功率和踏蹬频率，分别计算传统疲劳指数、频率指数和净疲劳指数。结果：运动员完成200m俯冲骑行到达终点前30s过程中，功率、频率前7s同时逐渐增加，8-11s功率增加但频率维持原来水平，功率在12-15s左右达到最大，此时频率约为130rpm左右，随后可见频率仍在增加，但功率逐步降低。场地自行车大坡俯冲骑行过程中，传统疲劳指数明显高于净疲劳指数，两者计算结果的差异来自与是否将频率变化包括在内。结论：净疲劳指数较传统疲劳指数更好地反映了场地自行车骑行中的功率-频率关系，并能描述不同速度下的疲劳程度。运动员可以通过适度增加传动比，降低频率来提高200m计时赛运动成绩。

Quantitative Analysis of Fatigue during High Intensity Exercise of Track Sprint Cycling

Objective: The power and cadence during the high intensity riding with different gear ratio in track sprint cycling were tested so as to find out the application value of the traditional fatigue index, cadence index and net fatigue index in evaluating fatigue.Method: Ten male track sprint cyclists performed two riding tests of flying 200m with the gear ratio of 50:12 and 50:13 respectively. The power and cadence of riding were recorded by SRM. The above-mentioned three fatigue indexes were calculated. Result: During the 30 seconds before the cyclists reached the terminal of the flying 200m, the power and cadence increased simultaneously in the first 7s. In 8-11s, the power continued to increase, but the cadence maintained the original level. The maximum power was observed around 12-15s. At that time, the cadence was about 130rpm. Then the cadence continued to increase, but the power decreased gradually. In the course of flying track riding, traditional fatigue index is higher than the net one. The difference of the calculation result is due to whether we take into account the cadence changes. Conclusion: Compared to the traditional fatigue index,the net fatigue index may better reflect the relationship between power and cadence in track riding. And it can explain the fatigue degrees in riding with different speed.Cyclists can improve their performance result of 200m time trial by increasing gear ratio and lowering cadence appropriately.