Effect of locomotor respiratory coupling induced by cortical oxygenated hemoglobin levels during cycle ergometer exercise of light intensity

Abstract

This study aimed to clarify the effects of locomotor-respiratory coupling (LRC) induced by light load cycle ergometer exercise on oxygenated hemoglobin (O2 Hb) in the dorsolateral prefrontal cortex (DLPFC), supplementary motor area (SMA), and sensorimotor cortex (SMC). The participants were 15 young healthy adults (9 men and 6 women, mean age: 23.1 ± 1.8 (SEM) years). We conducted a task in both LRC-inducing and LRC-non-inducing conditions for all participants. O2 Hb was measured using near-infrared spectroscopy. The LRC frequency ratio during induction was 2:1; pedaling rate, 50 rpm; and intensity of load, 30 % peak volume of oxygen uptake. The test protocol included a 3-min rest prior to exercise, steady loading motion for 10 min, and 10-min rest post exercise (a total of 23 min). In the measurement of O2 Hb, we focused on the DLPFC, SMA, and SMC. The LRC frequency was signifi cantly higher in the LRC-inducing condition (p < 0.05). O2 Hb during exercise was signifi cantly lower in the DLPFC and SMA, under the LRCinducing condition (p < 0.05). The study revealed that even light load could induce LRC and that O2 Hb in the DLPFC and SMA decreases during exercise via LRC induction.