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Interrupting Sedentary Behavior with Physical Activity Has Benefits

Jan 26, 2019
 
Editor: Joy Pape, MSN, FNP-C, CDE, WOCN, CFCN, FAADE

Author: Angela Reyes, Pharm.D. Candidate, LECOM College of Pharmacy

Small but frequent activity helps improve insulin concentrations and sensitivity in children with excess weight and obesity.

A sedentary lifestyle can lead to many health problems. It is well documented that blood glucose management is improved when prolonged sitting is interrupted every 30 minutes with physical activity. The American Diabetes Association (ADA) recommends three minutes or more of standing or light-intensity activities, such as leg lifts or extensions, overhead arm stretches, desk chair swivels, torso twists, side lunges, and walking in place. Children also benefit from physical activity, especially children with excessive weight or obesity. A new study examined if interrupting sitting time every 30 minutes improved glucose metabolism in this population.

 

On average, children are sedentary for at least six hours a day. This behavior leads to weight gain and metabolic issues like poor glucose metabolism. It has been shown that children with healthy body weight benefit from short bursts of exercise every 30 minutes. Improved insulin and glucose concentrations were seen after 3 minutes of moderate-intensity walking. The following study performed the same test for children who have excess weight or obesity to find if results were the same.

Participants enrolled in this study were 7-11 years old with a fasting glucose of <100 mg/dL. They had a BMI >85th percentile based on the CDC growth charts. Randomization was stratified based on sex, and study team members and participants were not blinded. Children were split into two groups — either a SIT group or a SIT + Walk group. There were a total of 35 children who completed the experiment and baseline characteristics were similar in both groups.

Participants in the sedentary group were required to sit for 3 hours while those in the Sit + Walk group walked on a treadmill for 3 minutes every 30 minutes for 3 hours. A 3-hour glucose tolerance test was performed twice on separate days for both the sitting group and the walking group. Blood samples were drawn at 20, 30, 60, 90, 120, 150, and 180 minutes. Participants also did not eat or drink anything besides the glucose solution until the 3 hours ended. Then children were given a buffet meal afterward to determine if calorie consumption differed between the two groups.

Results showed insulin secretion in the SIT+ Walk group was lower than the SIT group. The mean insulin concentrations were lower at minutes 60, 90, 150, and 180 in the SIT +Walk group. The mean insulin AUC was 21% lower in the active group than the sedentary group. This gave a Cohen d coefficient of 0.24 correlating to a small-moderate effect. C-peptide was lower in the Sit-Walk group with an AUC at 18% lower than the SIT group. A Cohen d coefficient of 0.36 was calculated signaling a moderate effect. There was no significant glucose difference among the two groups. Insulin sensitivity calculated by the Matsuda index was greater in the active group, but glucose effectiveness calculations showed no difference between the groups. Lastly, total calorie intake did not differ between the groups.

The data collected suggests children who have excess weight or obesity have better insulin concentrations and insulin sensitivity when participating in moderate intensity exercise for 3 minutes every 30 minutes. There was no change in circulating glucose or change in food intake with the interrupted exercise. Sustained exercise is known to improve uptake of non-insulin-mediated glucose, but brief moderate-intensity activity did not do that in this study. Also of note, children who performed more activity did not consume any more calories and this might, over longer periods, help in weight reduction.

Practice Pearls:

  • Breaking up a sedentary schedule with moderate exercise helps improve insulin concentration and sensitivity in children who have excess weight or obesity.
  • It is recommended to perform a moderate-intensity exercise like walking for 3 minutes every 30 minutes to get these results.
  • Plasma glucose levels and caloric intake did not differ with this change in activity.

References:

Miranda M. Broadney, Britni R. Belcher, David A. Berrigan, Robert J. Brychta, Ira L. Tigner, Faizah Shareef, Alexia Papachristopoulou, Jacob D. Hattenbach, Elisabeth K. Davis, Sheila M. Brady, Shanna B. Bernstein, Amber B. Courville, Bart E. Drinkard, Kevin P. Smith, Douglas R. Rosing, Pamela L. Wolters, Kong Y. Chen, Jack A. Yanovski

Effects of Interrupting Sedentary Behavior With Short Bouts of Moderate Physical Activity on Glucose Tolerance in Children With Overweight and Obesity: A Randomized Crossover Trial. Diabetes Care (Oct 2018) 41 (10) 2220-2228; DOI: 10.2337/dc18-0774

Alexandria, Virginia. American Diabetes Association Issues New Recommendations on Physical Activity and Exercise for People with Diabetes. American Diabetic Association(2016) http://www.diabetes.org/newsroom/press-releases/2016/ada-issues-new-recommendations-on-physical-activity-and-exercise.html

Angela Reyes, Pharm.D. Candidate, LECOM College of Pharmacy