Effect of exercise training on cerebral oxygenation and affects during exercise in obesity

Abstract

Exercise is a cornerstone for managing obesity, a complication of diverse respiratory disorders. Owing to, in part, low pleasure, these subjects yet perform little exercise. Left and right prefrontal cortex (PFC) activation are respectively related to positive and negative affects, while larger left PFC oxygenation (_oxy) on exertion is tied to cardiorespiratory fitness (CRF). High-intensity interval training (HIIT) is superior to moderate-intensity continuous training (MICT) on improving CRF in obesity. Yet, the effect of exercise training on PFC_oxy and affects during exercise in this population is unknown. Twenty obese subjects were randomized to MICT (50% peak work rate) or HIIT (1 min 100% peak work rate/1 min rest; 45 min, 3 sessions/week, 8 weeks). They completed an incremental bicycle test prior/after training. Near-infrared spectroscopy and the Feeling Scale respectively assessed both PFC_oxy and affects. Improvements in CRF (peak O₂ uptake %pred: 16±7 <i>vs</i> 10±7%) were larger in HIIT <i>vs</i> MICT (<i>p</i>&lt;0.05). Only HIIT improved left PFC_oxy alongside better affects on exertion (<b>Figure</b>; <i>p</i>&lt;0.05). Changes in PFC_oxy were related to the ones in CRF and post-training affective valence scores (<b>Figure</b>; <i>p</i>&lt;0.05). HIIT uniquely enhanced left PFC_oxy and affects on exertion in obese subjects. Our results may have implications for managing obesity as greater affective response to exercise predicts future adherence to physical activity.