The energy cost of stepping on the Nordicsport stepper in females

This study evaluated exercise on the NordicSport Stepper (NSS), a hydraulic stepping system. Twenty-eighty females (age = 18-41 yrs) volunteered as subjects. Each subject completed 3,5-minute workIoads at resistance level 3 on the NSS. They stepped in time with a metronome set at predetermined rates of 48, 56, and 66 steps per minute (spm), respectively. During all exercise sessions HR and RPE were recorded and expired air was analyzed using an automated open-circuit gas system each minute. There were no significant (p > .05) differences among step rates for VO2, (1.min-1, ml.kg-1min-1), RER, or kcal-min-1. Heart rate was significantly (p < .05) lower at rate 48 compared to rates 56 and 64. Peak VO2, and HR at rate 64 were 25 ml-kg-1min-1 and 145 bpm. Step height was significantly (p < .05) lower at rate 64. Total work (step height x spm) was significantly (p < .05) different at each rate of stepping. At a constant workload of 3 on the NSS, variations in step rate did not affect VO2, and thus, energy expenditure. Total work, however, significantly (p < .05) increased from the lowest stepping rate to the highest. A higher stepping rate, therefore, may indicate more efficient stepping pattern since the total work increased without a significant increase in the oxygen demand of the exercise