Maxwell Neil S, Castle Paul C, Spencer Matt
University of Brighton, Chelsea School Research Centre, UK.
J Sci Med Sport. 2008 Sep;11(5):491-9. doi: 10.1016/j.jsams.2007.05.008. Epub 2007 Aug 13.
This study compared two intensities of active recovery on intermittent sprint exercise performance and the development of heat strain in hot, humid conditions. Eight male game players completed four Cycling Intermittent Sprint Protocols (CISP) consisting of twenty 2-min periods, each including 10-s passive rest, 5-s maximal sprint against a resistance of 7.5% body mass and 105-s active recovery. The CISP was performed in mean (S.D.) temperate conditions with active recovery intensities of 50% V(O)(2peak) (TEMP50) and 35% V(O)(2peak)(TEMP35) and in hot, humid [35.2 (0.4) degrees C, 80.4 (2.1)% RH] conditions with the same intensities (HOT50 and HOT35, respectively) in a randomised, counterbalanced order. Heat strain (physiological strain index (PSI)) was calculated from rectal temperature and heart rate. All subjects completed the CISP (20 sprints) in TEMP50 and TEMP35. The mean number of sprints completed for HOT50 and HOT35 was 13 (3) and 17 (2), respectively; both of which were lower than TEMP50 and TEMP35 (P<0.01) and different between hot conditions. Reductions in peak power output (PPO) occurred in the TEMP50 and HOT50 by sprint 8 (P<0.05), but in HOT35 a reduction was delayed until sprint 13 (P<0.05). The rate of PSI increase was faster in HOT50 than TEMP50 and HOT35, but peak PSI was not different. By lowering the recovery intensity, one component of the PSI (heart rate) was reduced and intermittent sprint exercise performance was maintained for longer in the heat.
本研究比较了在炎热潮湿环境中，两种强度的主动恢复对间歇性冲刺运动表现及热应激发展的影响。八名男性运动员完成了四项自行车间歇性冲刺方案（CISP），每个方案包含二十个2分钟时段，每个时段包括10秒被动休息、5秒对抗相当于体重7.5%阻力的最大冲刺以及105秒主动恢复。CISP在平均（标准差）温带条件下进行，主动恢复强度分别为50%最大摄氧量（TEMP50）和35%最大摄氧量（TEMP35），并在炎热潮湿[35.2（0.4）℃，80.4（2.1）%相对湿度]条件下以相同强度（分别为HOT50和HOT35）按随机、平衡顺序进行。根据直肠温度和心率计算热应激（生理应激指数（PSI））。所有受试者均完成了TEMP50和TEMP35条件下的CISP（20次冲刺）。HOT50和HOT35条件下完成的冲刺平均次数分别为13（3）次和17（2）次；两者均低于TEMP50和TEMP35（P<0.01），且在炎热条件下存在差异。在TEMP50和HOT50条件下，到第8次冲刺时峰值功率输出（PPO）出现下降（P<0.05），但在HOT35条件下，下降延迟至第13次冲刺（P<0.05）。HOT50条件下PSI的增加速率比TEMP50和HOT35更快，但PSI峰值无差异。通过降低恢复强度，PSI的一个组成部分（心率）降低，并且在炎热环境中间歇性冲刺运动表现能维持更长时间。
