Effects of altered stride frequency on cardiorespiratory responses and ratings of perceived exertion during submaximal running

本研究的目的是探讨步频变化对积极运动的大学生的心肺反应和主观用力（RPE）的影响。该项目包括两个实验。实验一：10名受试者（5名男性和5名女性）进行5个6分钟改变步频运行在电动跑步机上在三个次最大速度（120，150和180转/分钟），分别。这五项试验涉及以自由选择的步频（FCSF）跑步，并且在每个速度下将FCSF改变+20%，+10%，-10%和-20%。在这些运行期间，在最后1分钟内测量摄氧量（VO_2）、心率（HR）、收缩压（SBP）和舒张压（DBP）以及RPE。作为心肌摄氧量的指标，计算率压乘积（PRP）等于HR（B/min）× SBP（mmHg）× 100。实验十一：五名男性受试者进行了三个30分钟的改变步频运行在电动跑步机在次最大速度（150或170米/分钟）。这三项试验涉及使用FCSF和改变+10%和-10%的FCSF运行。在这些运行期间，VO_2，HR，SBP和DBP血压，RPE和PRP每5分钟测量一次。所有受试者的FCSF或FCFS改变+10%，在此期间，心肺反应和RPE最小化，尽管个体曲线在6分钟运行期间变化很大。然而，PRP/VO_2在改变步频运行期间没有与FCSF运行期间不同。在30分钟的运行中，心肺反应表现出稳定状态，除了HR和RPE。虽然RPE随HR的增加而增加，但VO_2和血压并不增加。本项目的结果表明，改变步频（+10%）的短时间和长时间跑步对有氧工作能力训练的心肺功能都有许多好处。

The purpose of this project was to determine the effects of stride frequency variations on cardiorespiratory responses and ratings of perceived exertion (RPE) in active university students. The project consists of two experiments. Experiment 1 : Ten subjects (5 males and 5 females) performed five 6 min altered stride frequency runs on a motorized treadmill at three submaximal speeds (120, 150 and 180 re/min), respectively. The five trials involved running with a freely chosen stride frequency (FCSF) and a FCSF altered by +20%, +10%, -10% and -20% at each speed. During these runs, oxygen uptake (VO_2), heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure and RPE were measured during the last 1 min. As an index of myocardial oxygen uptake, rate pressure product (PRP) was calculated as equal to HR (b/min)x SBP (mmHg)x 100. Experiment 11 : Five male subjects performed three 30 min altered stride frequency runs on a motorized treadmill at a submaximal speed (150 or 170 m/min). The three trials involved running with a FCSF and a FCSF altered by +10% and -10%. During these runs, VO_2, HR, SBP and DBP blood pressure, RPE and PRP were measured every 5 min. All subjects exhibited a FCSF or a FCFS altered by +10% at which cardiorespiratory responses and RPE were minimized, although the individual profiles varied considerably during 6 min runs. However, PRP/VO_2 during altered stride frequency runs did not differ from during runs with a FCSF. During 30 min runs, cardiorespiratory responses exhibited in steady-state except HR and RPE. Although RPE increased with increases in HR, VO_2 and blood pressure did not increase. The results of this project suggest that both short and prolonged duration running with altered stride frequency (+10%) offer many advantages to cardiorespiratory functions for training of aerobic work capacity.