GENDER COMPARISON OF PEAK OXYGEN-UPTAKE - REPETITIVE BOX LIFTING VERSUS TREADMILL RUNNING

The gender differences in peak oxygen uptake ((V) over dot O-2peak) fo r various modes of exercise have been examined previously; however, no direct gender comparisons have been made during repetitive lifting (R L). In the present study the (V) over dot O-2peak between RL and tread mill 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 bo dy fat: 21 (3) years, 1.63 (0.05) m, 60 (7) kg, 27 (6)%, respectively] . (V) over dot O-2peak (1 . min(-1)), defined as the highest value obt ained during exercise to volitional fatigue, was determined using disc ontinuous protocols with treadmill grade or box mass incremented to in crease exercise intensity. For RL (V) over dot O-2peak, a pneumaticall y driven shelf was used to lower a loaded box to the floor, and subjec ts then lifted the box, at a rate of 15 lifts . min(-1) . (V) over dot O-2peak (1 . min(-1) and ml . kg(-1) . min(-1)) and minute ventilatio n ((V) over dot (E) 1 . min(-1)) were determined using an on-line gas analysis system. A two-way repeated measures analysis of variance reve aled significant gender effects, with men having higher values for (V) over dot O-2peak (1 . min(-1) and ml . kg(-1) . min(-1)) and (V) over dot (E), but women having higher values of the ventilatory equivalent for oxygen ((V) over dot (E)/(V) over dot O-2). There were also mode of exercise effects, with TR values being higher for (V) over dot O-2p eak (1 . min(-1) and ml . kg(-1) . min(-1)) and (V) over dot (E) and a n interaction effect for (V) over dot O-2peak {1 . min(-1) and ml . kg (-1) . min(-1)) and (V) over dot (E)/(V) over dot O-2. The women obtai ned a greater percentage (approximate to 84%) of their TR (V) over dot O-2peak during RL than did the men (approximate to 79%). There was a marginal tendency for women to decrease and men to increase their (V) over dot (E)/(V) over dot O-2 when comparing TR with RL. The magnitude of the gender differences between the two exercise modalities appeare d to be similar for heart rate, (V) over dot (E) and R, but differed f or (V) over dot O-2peak (1 . min(-1) and ml . kg(-1) . min(-1)). Lifti ng to an absolute height (1.32 m for the RL protocol) may present a di fferent physical challenge to men and women with respect to the degree of involvement of the muscle groups used during lifting and ventilati on.