Gender comparison of peak oxygen uptake: repetitive box lifting versus treadmill running.

The gender differences in peak oxygen uptake (VO2peak) for various modes of exercise have been examined previously; however, no direct gender comparisons have been made during repetitive lifting (RL). In the present study the VO2peak between RL and treadmill running (TR) was compared between 20 men [mean (SD) age, height, body mass and body fat: 21 (3) years, 1.79 (0.06) m, 81 (9) kg, 19 (6)%, respectively] and 20 women [mean (SD) age, height, body mass and body fat: 21 (3) years, 1.63 (0.05) m, 60 (7) kg, 27 (6)%, respectively]. VO2peak (l x min[-1]), defined as the highest value obtained during exercise to volitional fatigue, was determined using discontinuous protocols with treadmill grade or box mass incremented to increase exercise intensity. For RL VO2peak, a pneumatically driven shelf was used to lower a loaded box to the floor, and subjects then lifted the box, at a rate of 15 lifts x min(-1). VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and minute ventilation (VE, l x min[-1]) were determined using an on-line gas analysis system. A two-way repeated measures analysis of variance revealed significant gender effects, with men having higher values for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and VE, but women having higher values of the ventilatory equivalent for oxygen (VE/VO2). There were also mode of exercise effects, with TR values being higher for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and VE and an interaction effect for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]) and VE/VO2. The women obtained a greater percentage (approximately 84%) of their TR VO2peak during RL than did the men (approximately 79%). There was a marginal tendency for women to decrease and men to increase their VE/VO2 when comparing TR with RL. The magnitude of the gender differences between the two exercise modalities appeared to be similar for heart rate, VE and R, but differed for VO2peak (l x min(-1) and ml x kg(-1) x min[-1]). Lifting to an absolute height (1.32 m for the RL protocol) may present a different physical challenge to men and women with respect to the degree of involvement of the muscle groups used during lifting and ventilation.