More Sleep, More Exercise Linked to Lower Insulin Resistance in Adolescents

Adolescents who replace 30 minutes of daily sedentary time with either sleep or moderate-to-vigorous physical activity may lower insulin resistance, according to preliminary research presented at the American Heart Association EPI Lifestyle Scientific Sessions 2026. In the analysis, replacing sedentary time with moderate-to-vigorous physical activity was associated with nearly a 15% lower Homeostatic Model Assessment for Insulin Resistance score, while replacing it with sleep was associated with nearly a 5% reduction.

The findings suggest that relatively modest shifts in daily behavior may support cardiometabolic health during adolescence, a period when preventive counseling can have long-term implications. Investigators found that sedentary behavior accounted for the largest share of the day in this cohort, at 48%, or 11.5 hours daily. Sleep accounted for 33% of daily time, light-intensity physical activity for 17%, and moderate-to-vigorous physical activity for 2%.

“I was happily surprised with the strength of the association of replacing 30 minutes of sedentary time with moderate-to-vigorous physical activity—a 15% lower insulin resistance is quite a big change,” lead author Soren Harnois-Leblanc, PhD, RD, postdoctoral researcher, department of population medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, MA, in a press release. “Our findings mean that switching from sedentary behaviors to moderate-to-vigorous physical activity or sleep, even if it is only a few minutes per day to start, was beneficial for health.”

Researchers analyzed data from Project Viva, an ongoing longitudinal study of women and children in Eastern Massachusetts. In early adolescence, 802 participants with a median age of 12.9 years wore wrist accelerometers continuously for 7 to 10 days and completed sleep logs, allowing investigators to characterize how a typical 24-hour day was distributed across sleep, sedentary behavior, light physical activity, and moderate-to-vigorous physical activity.

In late adolescence, at a median age of 17.5 years, 394 participants with accelerometer data also underwent fasting blood testing for glucose, insulin, and adiponectin. Investigators used fasting glucose and insulin values to calculate HOMA-IR, an estimate of insulin resistance and a marker of future type 2 diabetes risk. Statistical models adjusted for age, sex, season of accelerometer wear, maternal education, and family income were then used to estimate how substituting 30 minutes from one activity domain to another might affect later metabolic measures.

The analysis found that shifting 30 minutes per day from sedentary time to moderate-to-vigorous physical activity was associated with nearly a 15% reduction in insulin resistance. Replacing the same amount of sedentary time with sleep was associated with nearly a 5% reduction. By contrast, replacing sedentary time with light-intensity physical activity was not associated with a significant change in insulin resistance. Activity composition also was not associated with adiponectin levels or fasting glucose.

“This study shows that young adolescents spend a lot of their day being sedentary and only a small amount of time being physically active,” Kershaw Patel, MD, chair elect, AHA Council on Epidemiology and Prevention, said in a press release. “Interestingly, teens who had more moderate to vigorous physical activity early in adolescence showed signs of lower insulin resistance later on. The big takeaway is being active early in life can really make a difference for long‑term health.” Patel, who was not involved in this study, is an assistant professor of cardiology at Houston Methodist Hospital’s DeBakey Heart & Vascular Institute in Houston.

Limitations to the study included insulin resistance data in late adolescence were available for only 49% of participants with early-adolescence accelerometer data, and the observational analysis cannot establish causality between daily activity patterns and insulin resistance. The research was presented as a scientific meeting abstract and remains preliminary until published in a peer-reviewed journal.

References:

1. Replacing Sedentary Time by Moderate-to-Vigorous Physical Activity or Sleep on a 24h Period in Early Adolescence Is Associated with Lower Insulin Resistance Five Years Later: Prospective Analysis Within the Project Viva Cohort. Abstract 71 presented at: American Heart Association EPI | Lifestyle Scientific Sessions: Boston, MA; March 17-20, 2026.
2. American Heart Association. More sleep and physical activity may prevent Type 2 diabetes in teens. News release. March 20, 2026. Accessed March 24, 2026. https://newsroom.heart.org/news/more-sleep-and-physical-activity-may-prevent-type-2-diabetes-in-teens