Effects of intermittent exercise during prolonged sitting on executive function, cerebrovascular and psychological response: A randomized cross-over trial

Emerging evidence indicates that acute bouts of uninterrupted prolonged sitting decrease cerebral blood flow and impair executive function. Few studies have investigated the use of feasible sedentary behavior interruptions to attenuate these effects. This study aimed to investigate effects of intermittent half-squat exercises during prolonged sitting on executive function. Twenty participants (45% women, 21±1 years) were randomized to sit for 3 h (i) without any interruptions (control) or (ii) with 1 min half-squats every 20 min (exercise). Executive function was determined using the Color Word Stroop Test (CWST) and Trail Making Test-B (TMT-B). Subjective feelings of arousal and measures of fatigue, concentration, and motivation were evaluated. Internal carotid artery (ICA) blood flow was measured using Doppler ultrasound. There was a significant interaction effect for correct response times with the incongruent CWST (P<0.01), which were 3.5% faster in the exercise and 4.2% slower in the control over 3 hours of sitting. There was also a significant interaction effect for TMT-B completion times (P<0.01) which were 10.0% faster in the exercise and 8.8% slower in the control. Exercise suppressed decreases in concentration with a significant interaction effect (-28.7% vs. -9.2% for control vs. exercise, P=0.048), and increases in mental fatigue with a significant interaction effect (285% vs. 157% for control vs. exercise, P<0.04). These changes may have been related to changes in ICA blood flow, which had a significant interaction effect (P=0.087). These results suggest that a simple strategy like intermittent squat exercises could help to maintain executive function during prolonged sitting.