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

aimsInterrupting 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.

methodsTwenty 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).

resultsOn 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.

conclusionIncreases 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.