Replacing Sedentary Time With Sleep or Activity May Reduce T2D Risk in Adolescents

Adolescents who replaced just 30 minutes of sedentary behaviors each day with moderate-to-vigorous physical activity or sleep may lower their insulin resistance, a key factor in preventing type 2 diabetes (T2D) development, according to preliminary research presented at the American Heart Association (AHA) EPI/Lifestyle Scientific Sessions 2026 in Boston, Massachusetts.¹

Study Design and Population

Researchers analyzed data from 394 adolescents (median age, 17.5 years) who wore accelerometers in late adolescence to measure physical activity patterns. Investigators used compositional data analysis to examine the distribution of 4 types of physical activities within a 24-hour period: sedentary time, light physical activity, moderate-to-vigorous physical activity (MVPA), and sleep. They then used modeling to estimate how 30-minute substitutions from one behavior to another could affect insulin resistance.¹

Fasting blood tests were collected to measure levels of adiponectin, glucose, and insulin. Fasting glucose and insulin levels were used to calculate the homeostatic model assessment of insulin resistance, a validated measure that informs on the risk of progressing to T2D. Results were adjusted for age, sex, season of accelerometer wear, mother’s educational level, and family income.¹

Key Findings on Insulin Resistance

Replacing 30 minutes of sedentary time with MVPA was associated with an approximately 15% reduction in insulin resistance. Similarly, replacing sedentary time with sleep also reduced insulin resistance. Although activity composition was associated with insulin resistance, it was not associated with levels of adiponectin or fasting glucose levels. The study revealed that younger adolescents spend a substantial portion of their day being sedentary and only a small amount of time being physically active.¹

“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,” Soren Harnois-Leblanc, PhD, RD, lead author of the study and a postdoctoral researcher in the Department of Population Medicine at the Harvard Pilgrim Health Care Institute and Harvard Medical School, said in a news release.¹

Adolescents who had more MVPA early in adolescence showed signs of lower insulin resistance later, suggesting that being active early in life can make a meaningful difference for long-term metabolic health. This finding aligns with research demonstrating that physical activity improves insulin sensitivity and reduces abdominal fat in children, adolescents, and young adults.^2,3

Current Physical Activity Recommendations

The AHA and CDC recommend that children and adolescents participate in at least 60 minutes of moderate-to-vigorous physical activity per day, including muscle-strengthening and bone-strengthening activities at least 3 days per week. Despite these recommendations, approximately only 1 in 5 youth achieve this guideline, with even lower rates observed among those with existing metabolic conditions.^4,5

The American Diabetes Association’s 2026 Standards of Care emphasize that moderate-intensity physical activity has been shown to improve insulin sensitivity and reduce abdominal fat in adolescents. The guidelines recommend that youth participate in 60 minutes of moderate-intensity aerobic activity daily, including resistance and flexibility training. Breaking up prolonged sedentary time may also lower postprandial glucose levels, providing an additional strategy for diabetes prevention.²

Implications for Pharmacists

Pharmacists can play an important role in diabetes prevention by counseling adolescents and their families about the metabolic benefits of replacing sedentary time with physical activity or adequate sleep. During medication therapy management encounters or health screenings, pharmacists should inquire about daily physical activity levels and screen time habits.

Pharmacists should reinforce that adolescents need at least 60 minutes of moderate-to-vigorous physical activity daily. Practical suggestions include walking or biking to school, participating in organized sports, taking active breaks during homework sessions, or engaging in family activities like hiking or dancing. Pharmacists can also educate families about limiting recreational screen time and encouraging activities that naturally reduce sedentary behavior.

For adolescents with risk factors for T2D, including obesity, family history, or prediabetes, pharmacists should emphasize the critical importance of early lifestyle intervention. The benefits observed in this study—particularly the 15% reduction in insulin resistance from replacing just 30 minutes of sedentary time—underscore that meaningful metabolic improvements are achievable through modest behavioral changes.

Pharmacists should collaborate with primary care providers to ensure at-risk adolescents receive appropriate screening and are connected to community resources such as youth fitness programs or registered dietitian nutritionists.

REFERENCES

1. More sleep and physical activity may prevent type 2 diabetes in teens. News release. American Heart Association. March 20, 2026. Accessed March 23, 2026. https://newsroom.heart.org/news/more-sleep-and-physical-activity-may-prevent-type-2-diabetes-in-teens

2. American Diabetes Association Professional Practice Committee for Diabetes. 3. Prevention or delay of diabetes and associated comorbidities: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(suppl 1):S50-S60. doi:10.2337/dc26-S003

3. García-Hermoso A, Ramírez-Vélez R, Ramírez-Campillo R, Peterson MD, Martínez-Vizcaíno V. Concurrent aerobic plus resistance exercise versus aerobic exercise alone to improve health outcomes in paediatric obesity: a systematic review and meta-analysis. Br J Sports Med. 2018;52(3):161-166. doi:10.1136/bjsports-2016-096605

4. Colley RC, Carson V, Garriguet D, Janssen I, Roberts KC, Tremblay MS. Physical activity of Canadian children and youth, 2007 to 2015. Health Rep. 2017;28(10):8-16.

5. Kohl HW 3rd, Craig CL, Lambert EV, et al; Lancet Physical Activity Series Working Group. The pandemic of physical inactivity: global action for public health. Lancet. 2012;380(9838):294-305. doi:10.1016/S0140-6736(12)60898-8