Maximal constant heart rate--a heart rate based method to estimate maximal lactate steady state in running.

The aim of the present study was to investigate the accuracy of the maximal constant heart rate method for predicting anaerobic threshold (AnT) in running. This method only requires a common heart rate (HR) monitor and is based on the identification of the maximal constant HR maintainable for 30 min (HRMC). HRMC, 4-mmol threshold, and maximal lactate steady state (MLSS) were determined in 31 probands. 17 probands underwent an additional MLSS retest within 2 weeks. The correlation between HR at MLSS and at MLSS retest was very close (r = 0.807; SEE = 5.25 beats x min(-1); p < 0.001). So were the correlations between HR at 4-mmol threshold and MLSS (r = 0.844; SEE = 6.43 beats x min(-1); p < 0.001) and between HRMC and HR at MLSS (r = 0.820; SEE = 6.73 beats x min(-1); p < 0.001). Mean velocities at maximum constant HR trials and MLSS (r = 0.895; SEE = 0.185 m x s(-1); p < 0.001) as well as 4-mmol threshold and MLSS (r = 0.899; SEE = 0.186 m x s(-1); p < 0.001) were highly correlated. In conclusion, data presented in this study confirm that the determination of HRMC is a manageable method giving a highly accurate estimation of both HR and velocity at MLSS in running.