Changes in running economy at different intensities following downhill running
Changes in running economy at different intensities following downhill running
复制标题
DOI：
10.1080/02640410903062027
复制
发表时间：
2009-01-01
影响因子：
3.4
通讯作者：
Wu, Chang-Jun
中科院分区：
文献类型：
--
作者：
Chen, Trevor C.;Nosaka, Kazunori;Wu, Chang-Jun
在这项研究中，我们测试了假设，运行经济评估在高强度[e。G.在下坡跑后，90%最大氧容量（（V）超过点O-2 max）]将比在较低强度下（例如，70%（V）超过点O-2 max）受到更大的影响。15名未经训练的年轻人在进行30分钟的下坡跑（坡度为-16%）之前和之后的2天和5天，以70%（V）的强度超过点O-2 max（每种强度5分钟）进行水平跑。在水平跑过程中测量氧耗量、每分钟通气量、呼吸交换率、心率、主观用力评分和血乳酸浓度，并结合运动学测量（e. G.步幅和频率）。下坡跑导致膝关节伸肌最大等长肌力显著下降（P < 0.05），肌肉酸痛程度加重，血浆肌酸激酶活性和肌红蛋白浓度升高，并持续至下坡跑后5d。在下坡跑后第2天和第5天，在80%和90%（V）超过点O-2 max时，所有跑步经济性和运动学指标与基线相比均发生显著（P < 0.05）变化，但在70%（V）超过点O-2 max时变化不明显。这些结果表明，在高强度下评估的跑步经济性比在低强度下（低于乳酸阈值）受到更多的影响。
In this study, we tested the hypothesis that running economy assessed at a high intensity [e. g. 90% maximal oxygen capacity ((V) over dot O-2max)] would be affected more than at a lower intensity (e.g. 70% (V) over dot O-2max) after downhill running. Fifteen untrained young men performed level running at 70, 80, and 90% (V) over dot O-2max (5 min for each intensity) before and 2 and 5 days after a 30-min downhill run (gradient of -16%) at the intensity of their pre-determined 70% (V) over dot O-2max. Oxygen consumption, minute ventilation, respiratory exchange ratio, heart rate, rating of perceived exertion, and blood lactate concentration were measured during the level runs together with kinematic measures (e. g. stride length and frequency) using high-speed video analysis. Downhill running resulted in significant (P < 0.05) decreases in maximal isometric strength of the knee extensors, the development of muscle soreness, and increases in plasma creatine kinase activity and myoglobin concentration, which lasted for 5 days after downhill running. Significant (P < 0.05) changes in all running economy and kinematic measures from baseline were evident at 2 and 5 days after downhill running at 80% and 90% (V) over dot O-2max, but not at 70% (V) over dot O-2max. These results suggest that running economy assessed at high intensity is affected more than at low intensity (lower than the lactate threshold).