Objective: 

Clinical exercise test can provide an objective evaluation of the body's response to exercise stress. The cardiorespiratory and metabolic changes in response to aerobic and anaerobic regions of the incremental exercise test were comparatively examined in trained subjects.

Methods: 

After giving a signed informed consent which was approved by the local ethical committee, total of 24 male trained subjects (19.75±0.3 yr, 70.1±1.8 kg) performed an incremental exercise test. Following a 4 min of warm-up period at 20 W, the work rate increased by a work rate controller as 15 W/min until the subjects could not tolerate. During exercise, ventilatory and pulmonary gas exchange parameters were measured using metabolic system and turbine volume transducer and evaluated breath-by-breath. Anaerobic threshold (AT) was estimated using V-slope method. Paired t test was used to analyze data (p<0.05).

Results: 

Maximal exercise capacity, work rate at the AT, maximal O2 uptake (VO2max) and VO2max for body weight was found to be 232.7±6.2 W, 156.2±5.04 W, 2.93±0.06 L/min and 42.3±0.001 ml/kg/min, respectively. Minute ventilation to work rate ratio was 3.78±0.1 L/min for aerobic region and 1.63±0.1 L/min for anaerobic region (p<0.05). Work rate to heart rate ratio was found to be 2.752±0.19 W/beat/min for aerobic and 2.205±0.11 W/beat/min for anaerobic regions (p<0.05).

Conclusions: 

The patterns of cardiopulmonary variables throughout the range of exercise intensities were shown to be affected with the metabolic activity. Consequently, determining the metabolic effect on cardiopulmonary variables could be important alternative endpoints that might be better used to indicate sedentary subjects or patients capacity to cope with the metabolic demands encountered during physical activity.