Cardiorespiratory responses of sedentary college women as a function of training intensity

Twenty-seven sedentary college women trained on a treadmill 3 times weekly over a 9-wk experimental period. Subjects exercised at a heart rate (HR) of either 50 or 65% of the HR reserve added to the resting HR with the duration of each session limited to the time required to elicit 1,000 beats above the resting value. Treadmill speed was adjusted automatically to maintain the prescribed exercise heart rate (EHR) within +/- 5 beats-min(-1). A comparison of the pretraining and posttraining results revealed that both training intensities caused significant increases in VO2max (1-min(-1) and ml-kg(-1)-min(-1)), V at VO2max, and O2 pulse at VO2max, and a significant decrease in VEO2 at VO2max. There was no alteration in EHR at VO2max for either intensity. For every dependent variable in which training effects were noted, the absolute gain made by the subjects training at the 65% intensity was greater than for those exercising at 50%. In no instance, however, was the difference between groups statistically significant. It was concluded that training at an EHR of either 50 or 65% of the HR reserve plus resting HR is sufficient to elicit a training response.