Training-Induced Changes in the Respiratory Compensation Point, Deoxyhemoglobin Break Point, and Maximal Lactate Steady State: Evidence of Equivalence

Purpose : To evaluate whether the coherence in the oxygen uptake ( ) associated with the respiratory compensation point (RCP), near-infrared spectroscopy-derived muscle deoxyhemoglobin ([HHb]) break point ([HHb] BP ), and maximal lactate steady state (MLSS) would persist at the midpoint and endpoint of a 7-month training and racing season. Methods : Eight amateur male cyclists were tested in 3 separate phases over the course of a cycling season (PRE, MID, and POST). Testing at each phase included a ramp-incremental test to exhaustion to determine RCP and [HHb] BP . The PRE and POST phases also included constant power output rides to determine MLSS. Results : Compared with PRE, at both RCP and [HHb] BP was greater at MID (delta: RCP 0.23 [0.14] L·min −1 , [HHb] BP 0.33 [0.17] L·min −1 ) and POST (delta: RCP 0.21 [0.12], [HHb] BP 0.30 [0.14] L·min −1 ) ( P