0369 Zero-time Exercise on Physically Inactive Adults with Insomnia Disorder: A Randomized Controlled Trial

Abstract Introduction Exercise is a potential treatment for insomnia. However, lack of time is a major barrier to starting and maintaining exercise. Therefore, a brief exercise training program, called Zero-time Exercise (ZTEx), was developed to relieve insomnia. ZTEx is a simple exercise that can be incorporated into habitual daily routines, requiring no extra time or equipment. This study examined the effectiveness of a ZTEx intervention program on sleep and related outcomes in inactive adults with insomnia disorder. Methods This randomized controlled trial (RCT) included 140 physically inactive adults (mean age: 46.7 years, SD: 14.0; 82.1% female) with insomnia disorder from the community. They were randomly assigned to ZTEx training or sleep hygiene education (SHE) group. Subjects received two 2-hour ZTEx training or SHE lessons according to their group allocation. They were told to practice ZTEx or follow sleep hygiene instructions for 24 weeks. The primary outcome measure was the Insomnia Severity Index (ISI) at weeks 8, 16, and 24. The secondary outcomes included sleep parameters by subjective sleep diaries and objective actigraphy; objective physical activity levels assessed by waist-worn accelerometers; and anxiety, depression, and fatigue levels evaluated by questionnaires. Results Compared with the SHE group, a significantly greater reduction of ISI was observed in the ZTEx group at week 24 (d = 0.60, P = 0.005). No significant between-group difference was observed in sleep parameters measured by sleep diary or actigraph at all study visits, except that sleep-diary-derived wake time after sleep onset was significantly lower in the ZTEx group at week 8 (d = 0.24, P = 0.035). The ZTEx group showed a significant improvement in the Multidimensional Fatigue Inventory (MFI) reduced-activity subscore (d = 0.27, P = 0.036) and reduced-motivation subscore (d = 0.33, P = 0.013) at week 8, but also a higher MFI physical fatigue (d = -0.58, P = 0.008). Conclusion The ZTEx training program improves physically inactive individuals’ insomnia severity and daytime impairment. Support (if any) The study was supported by the Research Grants Council, General Research Fund, Hong Kong SAR (Project no.: 15100419)