the ventilatory threshold in sedentary men

  The aim of this study was to survey of the relationship between heart rate deflection point (HRDP) by the short distance maximum (S.Dmax) and second ventilatory threshold (VT2). Twenty-one sedentary men volunteers (mean age 19.9±1.31 years; height 173.4±5.3 cm; weight 67.9±8.9 kg; maximum oxygen uptake 3.08±0.52 L.min-1) performed an incremental treadmill exercise test to exhaustion. To determine the HRDP, each subject heart rate was recorded by using a polar monitor and analyzed by a designed computer program. Respiratory gases during the exercise test was measured with a gas analyzing system. Data were analyzed using depended t-test, Bland and Altman plots and intraclass correlation coefficient. The HRDP was noticed in all subjects. No significant difference (p > 0.05) between the heart rate, oxygen uptake, ventilation, tidal volume and respiratory rate corresponding to HRDP and VT2. Also, results of ICC and Bland-Altman plots showed a good agreement between HR and VO2 measured at the HRDP and VT2. It could be concluded that S.Dmax method is an accurate and reliable alternative to the expensive and time-consuming invasive methods. Therefore, the S.Dmax method can be used for the determination of anaerobic threshold in healthy young men.