Effect of Exercise Duration on Post-Exercise Persistence of Oxyhemoglobin Changes in the Premotor Cortex: A...

Measurement of oxyhemoglobin (O₂Hb) changes in the cerebral cortex using near-infrared spectroscopy (NIRS) shows that its levels increase during moderate-intensity exercise and persists after exercise. However, the effects of exercise duration on O₂Hb persistence in the premotor cortex (PMC) are unknown. We aimed to determine the effects of exercise duration on the persistence of O₂Hb changes after moderate-intensity cycling as exercise. Healthy young volunteers were recruited to participate in this study. After a 3-min rest period, the exercise was initiated at a workload corresponding to 50% VO₂peak. The exercise continued for 10 min and 20 min, followed by 15 min of rest. The O₂Hb levels in the right (R-PMC) and left premotor cortices (L-PMC) were measured using an NIRS system. The O₂Hb values during the 15-min post-exercise rest period in the R-PMC were 0.010 ± 0.011 mM·cm after the 10-min exercise and 0.035 ± 0.010 mM·cm after the 20-min exercise, without significant differences (p = 0.104). The O₂Hb value in the L-PMC during post-exercise rest (0.055 ± 0.010 mM·cm) after the 20-min exercise was significantly higher than that after the 10-min exercise (0.023 ± 0.007 mM·cm; p = 0.014). Thus, the effects of exercise duration on O₂Hb persistence have laterality in the PMC.