Effect of high-endurance exercise intervention on sleep-dependent procedural memory consolidation in individuals with schizophrenia: a randomized controlled trial
Lincoln Lik Hang Lo, Edwin Lee, Christy Lai Ming Hui, Catherine Shiu Yin Chong, Wing Chung Chang, Sherry Kit Wa Chan, Jingxia Lin, William Tak Lam Lo, Eric Chen
Abstract
Abstract Background Little is known about the effects of physical exercise on sleep-dependent consolidation of procedural memory in individuals with schizophrenia. We conducted a randomized controlled trial (RCT) to assess the effectiveness of physical exercise in improving this cognitive function in schizophrenia. Methods A three-arm parallel open-labeled RCT took place in a university hospital. Participants were randomized and allocated into either the high-intensity-interval-training group (HIIT), aerobic-endurance exercise group (AE), or psychoeducation group for 12 weeks, with three sessions per week. Seventy-nine individuals with schizophrenia spectrum disorder were contacted and screened for their eligibility. A total of 51 were successfully recruited in the study. The primary outcome was sleep-dependent procedural memory consolidation performance as measured by the finger-tapping motor sequence task (MST). Assessments were conducted during baseline and follow-up on week 12. Results The MST performance scored significantly higher in the HIIT ( n = 17) compared to the psychoeducation group ( n = 18) after the week 12 intervention ( p < 0.001). The performance differences between the AE ( n = 16) and the psychoeducation ( p = 0.057), and between the AE and the HIIT ( p = 0.999) were not significant. Yet, both HIIT ( p < 0.0001) and AE ( p < 0.05) showed significant within-group post-intervention improvement. Conclusions Our results show that HIIT and AE were effective at reverting the defective sleep-dependent procedural memory consolidation in individuals with schizophrenia. Moreover, HIIT had a more distinctive effect compared to the control group. These findings suggest that HIIT may be a more effective treatment to improve sleep-dependent memory functions in individuals with schizophrenia than AE alone.