An Evening Activity Breaks Intervention for Improvement of Glucose, Blood Pressure, and Sleep: A Pilot Study in Free-Living Adults

AIMS: Interrupting evening sedentary time with activity breaks in a laboratory setting improves postprandial metabolism and sleep duration. This pilot study aimed to assess if a theory-informed intervention was able to increase the number of activity breaks performed in the evening at home, and to describe changes in movement patterns, glycaemic response and blood pressure. METHODS: Twenty participants (mean age 34 ± 12 years, female n = 18) completed a 2-week intervention which supported them to perform 2-3 min activity breaks every 30 min during periods of prolonged sitting in the evening. The intervention utilised behaviour change techniques and a mobile application. The number of activity breaks performed was assessed via self-report, mobile app data, and accelerometer data. Other outcomes included: glycaemic control; 24-h movement patterns; blood pressure; self-reported sleep and capability, opportunity and motivation to interrupt evening sitting. Data was collected at baseline, 2-weeks (immediately post-intervention) and 4-weeks (following a 2-week follow-up period). RESULTS: On average, participants self-reported completing 3.6 activity breaks per evening during the intervention. There was little change in objective measures of sedentary time, sleep, physical activity, and glycaemic outcomes. A reduction in sleep disturbances (-0.35, 95% CI -0.6 to -0.1), as measured by the PSQI, was observed. Participants reported improved automatic motivation to interrupt evening sitting, but capability, opportunity and reflective motivation were unchanged. CONCLUSION: Increases in the number of activity breaks performed in the evening can be achieved and were accompanied by small improvements in sleep quality. A full-scale effectiveness RCT based on this intervention is warranted.