Abstract:

Maximal exercise capacity (Wmax) and anaerobic threshold (AT) are important tools used non-invasively to evaluate aerobic fitness levels and clinically possible risk. It has been shown that O2 uptake to heartbeat ratio (O2 pulse) at the maximal exercise test is an important parameter used to evaluate fitness levels of the subjects. However, O2 pulse at the anaerobic threshold and fitness status of the subjects has not been described yet. In this study, we comparatively evaluated the fitness levels and O2 pulse at AT and at Wmax in healthy young male subjects during an incremental exercise test. A total of 20 healthy male performed an incremental exercise test (15 W/min) to exhaustion on a cycle ergometer. Ventilatory and pulmonary gas exchange parameters were measured breath-by-breath using the metabolic gas analyser and turbine volume-meter. AT has been estimated using the V-slope method. The work rate at AT and Wmax was found to be 135 ± 4 W and 225 ± 4 W, respectively. O2 pulse was found to be 13.49 ± 0.3 ml/beat at AT and 16.53 ± 0.31 ml/beat at Wmax. There was a significant positive correlation between Wmax and O2 pulse R = 0.75184 (P < 0.05). In addition, there was a significant correlation between work production capacity for each kg of body weight and O2 pulse R = 0.68811 (p < 0.0001). We have shown that O2 pulse at AT can also be used to evaluate the fitness status. Thus, considering effective fitness measurement at the AT, investigators should be avoiding difficulty in maximal exercise performance.

Keywords: