The Relationship between body weight and oxygen uptake during exercise in humans

In the present study, we wished to examine the relationships between O2 uptake (VO2) and work rate (WR) during ramp incremental exercise tests in normal subjects. Eighteen healthy male subjects (Mean ± SD, 23.6 ± 4.1 yr.) performed a ramp incremental exercise tests (15 W/min) to the limit of tolerance using an elctromagnetically-braked cycle ergometer. Ventilatory and pulmonary gas exchange were measured by a turbine volume transducer and a mass spectrometry. VO2 measured non-invasively and estimated breath-by-breath. The maximal VO2 in relation to the body weight was varied among subjects 27.6 ml/min/kg (minimum) and 52.5 ml/min/kg (maximum). Despite the fact that maximal VO2 and WR were differed among subjects (3.108 ± 0.542 1/min and 246 ± 39 W/min), respectively, there was no systematic change in the linear increase of VO: with WR. Furthermore, the ratio of AV02/AWR was 10.3 ± 1.2 ml/min/W. Consequently, these results may suggest that VO2 is more related to the mitochondrial respiration rather than O2 supply to exercising muscles. 61