Physical work capacity and maximum oxygen uptake in treadmill and bicycle exercise.

The metabolic, heart rate and ventilatory patterns and physical work capacity in bicycle and treadmill exercise were compared in 23 male college students. The average reduction in max Vo2 of .324 l/min (9.9%) observed during bicycle work was highly significant (P < 0.01). The standard error of the prediction for max Vo2 on the treadmill from observed values on the bicycle ergometer was ± .291 l/min (r=0.82). Minute ventilatory volume was similar at all measured work levels in both forms of exercise with the respiratory exchange ratio being significantly higher on the bicycle at submaximal heart rates and at max Vo2 A significantly larger percentage of the max Vo2 was elicited at submaximal heart rates on the bicycle when compared to similar heart rates on the treadmill. At max Vo2 the heart rate was significantly lower in the bicycle test. PWC150 and PWC170 on the bicycle ergometer correlated fairly well with similar measures on the treadmill. However, when PWCmax was compared in both tests the relationship was significantly reduced (r=0.34). PWC on the bicycle was favored more by a high absolute max Vo2 (l/min), whereas the relative max Vo2 (ml/kg/min) was highly related to treadmill exercise. This was particularly demonstrated at PWCmax on the treadmill with work capacity correlating r=0.92 and r=0.37 with relative and absolute max Vo2, respectively. However, when the effect of body weight was held statistically constant the partial correlation between max Vo2 (l/min) and PWCmax on the treadmill increased to r12.3=0.91. Expressing the oxygen uptake in terms of lean body weight did not improve its relationship to PWC on the bicycle or treadmill.