Introduction:
Several indices of ventilatory efficiency (VE) have provided an extra measure to assess cardiorespiratory fitness in addition to oxygen uptake (VO2) at peak exercise and at the level of ventilatory threshold (VO2VT). In patients with heart failure has been demonstrated that there is increase of ventilatory efficiency after training. However, the sensitivity of this measure to assess the effect of training in health subjects has been little studied.
Objective:
To test the hypothesis that a training program designed to improve aerobic fitness also changes the ventilatory efficiency in healthy subjects.
Methods:
48 men seemingly healthy and active (24±5 years) underwent a cardiopulmonary exercise test (CPET) before and after 13 weeks of aerobic training, performed three times a week for 30 minutes with the initial intensity 60-65% of maximum heart rate (HRmax) gradually increased until the end of program for 85-90% of HRmax. The parameters evaluated included: VO2peak, VO2VT and ventilatory efficiency that was determined by calculating the slope of the relationship between ventilation and production of carbon dioxide by linear regression.
Results:
There was a 12.5% increase in VO2VT (30.4 ± 4.5 vs. 34.2 ± 4.9 ml.kg-1.min-1, p <0.05) and 10.9% in VO2peak (53.2 ± 8.3 vs. 59 ± 9.9, ml.kg-1.min-1 p<0.05), accompanied by a 4.1% reduction in VE-VCO2 slope (25.2 ± 3.3 vs. 24.2 ± 3.7, p<0.05).
Conclusion:
Ventilatory efficiency increases after training in healthy men suggesting that the slope of the relationship VE-VCO2 can be used in addition to the monitoring of the effects of training, complementing the interpretation of cardiorespiratory integration of CEPT.
Physical fitness; pulmonary ventilation; oxygen consumption; exercise test; exercise