The Canadians have done it again! In the August issue of Pediatrics, Guerrero and her colleagues from the Healthy Active Living and Obesity (HALO) Research Group in Ontario (10.1542/peds.2019-0187) released some interesting results from a large cross-sectional study looking at relationships between impulsivity and patterns of movement and sleep in children 8-11 years old.
Our neighbors to the north have long been pioneers in the advancement of appropriate levels of physical activity. Several years ago, they coalesced evidence-based recommendations for screen time, sleep and physical activity into the Canadian 24-Hour Movement Guidelines for children. Their recommendations for the age group in this study:
- Sweat: 60 minutes of moderate to vigorous activity/day
- Step: Several hours of light physical activity/day
- Sleep: 9-11 hours of uninterrupted sleep/night
- Sit: Less than 2 hours of sedentary screen time/day and limit extended periods of sitting
Guerrero et al specifically looked at associations between impulsivity and different combinations of sleep duration, moderate-vigorous physical activity, and screen time. The data on how few children are meeting these recommendations is a real “wake up” call; only 5% of children met all of these recommendations, and 30% of children did not meet ANY of them. Their results outline relationships between these factors, but the bottom line is that meeting sleep and screen time recommendations have the strongest associations with reduced impulsivity. While this cross-sectional study does not prove causation, it does lend added support to the known benefits of adhering to their current guidelines. No wonder our children are struggling!
For the practicing pediatrician, there are 2 points worth emphasis when considering results of this study:
- Each child is a unique combination of impulsivity related to developmental stage and “trait impulsivity” related to biologic/genetic factors. This leads to a great deal of inter-individual variability on the impacts of activity and sleep on brain function and behavior. Some kids are going to be more sensitive to these effects than others.
- Chronic sleep deprivation is not necessarily associated with sleepiness. The nightly mantra of “I’m not tired” uttered by many youngsters at bedtime may be truly reflective of how they feel, but is not indicative of what they need. Attention to the clock, good sleep hygiene, and separating children from their devices to avoid excessive use, not only prepare children for the 9-11 hours of sleep they need each night, but is “high yield” advice all the way around.