Comparison of the heart rate deflection point determination methods

Anaerobic threshold (AT) is defined as the exercise intensity that is associated with a substantial increase in blood lactate during an incremental exercise. Conconi et al. developed a field test for the indirect and noninvasive determination of the AT. This test was based on the observed deviation from linearity (heart rate deflection point- HRDP) in the heart rate (HR) ? work intensity relationship during progressive incremental exercise. This study purposes to determine whether HRDP changes or not by using different test protocols; and in addition, to see if there is a difference between the HRDP findings according to methods of calculation. Fourteen soccer players (19.07 ± 1.21 years) who plays on Balcova Belediyesi Termal Sports Club Young Team, volunteered to take part in this study. Athletes performed three different proggressive incremental exercise test on a cycle ergometer. The first one is designed for the determination of the aerobic capasity and of the anaerobic threshold and the other two for the determination of the HRDP. Heart rates of athletes recorded in 5 s intervals during HRDP determination tests. From these HR values HRDP assessed by two different methods which are visual inspection and mathematical modeling (regression analyze). HRDP is determined on twelve athletes with two calculation methods and in two different test protocols. On one of the athletes HRDP isn?t determined. And HRDP couldn?t be calculated with mathematical modeling in which test protocol work intensity increased 40 Watt/2min on one of the athletes. When heart rates at HRDP and work intensities at HRDP compared; and when they compared with heart rates at AT and work intensities at AT, no significant difference is found (p>0.05). As a result, when the different test protocols used for determination of the HRDP, it isn?t changed and there isn?t any statistically significant difference between two calculation methods of the HRDP.