Figure 1

Mean log ₁₀ rMSSD at rest and during the first 3 min of recovery from each cardiopulmonary exercise test. Error bars have been omitted to aid clarity. * Resting log₁₀ rMSSD significantly higher than each time point during the 3 min recovery period for each cardiopulmonary exercise test (P < 0.001); ** log₁₀ rMSSD at each successive time point between 30 and 150 s significantly higher (P < 0.001); † cycling vs. walking (P < 0.001); ‡ cycling vs. running (P < 0.001); # walking vs. running (P < 0.001).