Abstract

Objective: Ventilatory efficiency, which describes the ratio between ventilation to CO2 output (VE/VCO2) during an incremental exercise test has been used to evaluate fitness levels of the subjects. During exercise, the lowest VE/VCO2 ratio above 34 shows increased mortality levels. In the present study, we comparatively evaluated ventilatory efficiency in trained and sedentary males that the lowest VE/VCO2 ratio could be related fitness levels of the subjects. Materials and Methods: Ten trained (age: 20.1±0.4 yr) and 10 sedentary (age:19.8±0.7 yr) male subjects were performed an incremental exercise (15 W/min) test. Ventilatory gas exchange parameters were evaluated breath-by-breath using metabolic gas analyser. Anaerobic threshold (AT) and respiratory compensation point (RCP) estimated from the gas exchange values. Results: Work rates for trained and sedentary subjects were found to be 143±8 W vs 123±5 W at the AT, 170±9 W vs 148±6 W at the RCP and 222±9 W vs 204±7 W at the end of the test, respectively. VE/VCO2 ratio for trained and sedentary subjects were found to be 32±0.6 vs 32±1.6 at the beginning of test and 26.5±0.7 vs 26±1 at the AT, 27.5±0.7 vs 26±0.9 at the RCP and 30±1.1 vs 30±1.3 at the end of the test. Conclusion: The lowest VE/VCO2 ratio, reflects optimal ventilatory efficiency obtained at the AT and RPC, was not statistically different in both groups. While increased VE/VCO2 ratio could be a useful criteria to evaluate reduced aerobic fitness levels, it can not be use to indicate increased aerobic fitness levels.

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