Protocol for the Conconi test and determination of the heart rate deflection point.

Recently Ozcelik and Kelestimur (2004) have assessed the validity of the heart rate deflection point in the power output-heart rate relationship (Conconi test) for estimating the anaerobic threshold in different experimental conditions (normoxia and hypoxia). In their study, the tests were performed with an electromagnetically braked cycle ergometer at constant cadence with increments in power output obtained by increasing the pedalling resistance. In cycle ergometry, modifications of the testing protocol give rise to modifications of neurohumoral and gas exchange responses (Gullestad et al. 1997), of power outputs at given respiratory exchange ratios (Amann et al. 2004) and modifications of the relationship between work rate, oxygen uptake and heart rate (Myers and Froelicher 1990). In this letter, we discuss the differences between the testing protocol used by Ozcelik and Kelestimur and the one developed by Conconi et al. (1996) and Grazzi et al. (1999). Three points of the testing procedure used by the authors will be particularly considered.