Figure 4.

Shown above is a correlation matrix of all this study's best traditional variables typically used to describe human endurance performance along with indices of maximal rates of skeletal muscle respiration. Variables include absolute (_abs; L·min⁻¹) rates of whole‐body oxygen consumption (VO₂), relative (_rel; ml·min⁻¹·kg^−0.32) VO₂, power (W·kg^−0.32), gross efficiency (GE), exercise economy (EC), cycling economy (CE), rate constant for the recovery of skeletal muscle oxygen consumption (k) or the reciprocal time constant for the recovery of skeletal muscle oxygen consumption (T_c). Traditional measures of VO₂ or power collected at maximal efforts were averaged (_max). All fatigue thresholds were determined using the ventilatory equivalents (VEQ) method. Indices of exercise efficiency were determined during cadence‐controlled cycling (80 rpm) at either 50 or 100 W