A pilot randomized controlled trial examining the impact of a sleep intervention targeting home routines on young children's (3-6 years) physical activity.

Background: Given evidence suggesting that sleep impacts on metabolic processes, interventions targeting sleep may improve child physical activity (PA).

Objectives: To describe the potential effect of an intervention to increase sleep on young children's (3-6 years) moderate to vigorous PA (MVPA) and total PA. To determine adherence to the intervention, impact on sleep duration as well as feasibility, uptake and acceptability was also assessed.

Methods: Pilot randomized controlled trial with 76 parent-child dyads randomly allocated to an intervention (n = 38) or control group (n = 38). Parents in the intervention group received a 3-month theory-informed intervention consisting of an online video, a telephone call and two text messages. Child PA was assessed using accelerometers at baseline and approximately 3 months. Parents also completed a sleep log and a telephone interview.

Results: The consent rate was 41% (76/186). Estimated effect size for the intervention relative to control was 10.8 min/day for MVPA, 2.7 min/day for PA and 0.9 h for sleep. Sixteen (44%) parents accessed the video, and 18 (50%) received the telephone call. Over 40% of parents found the video and telephone call useful/very useful.

Conclusions: This study reports promising effects that an intervention targeting sleep may improve child MVPA and sleep duration. Some modifications to data collection methods and intervention delivery are needed.