Short ‘Activity Snacks’ Help Maintain Muscle Mass

Rockville, Md. (October 19, 2022)—Interrupting prolonged sitting with periodic “activity snacks” may help maintain muscle mass and quality, according to researchers at the University of Toronto in Canada. Activity snacks, or moderate intensity exercise – such as two minutes of walking or body weight sit-to-stand squats – allow the body to use more amino acids from meals to build muscle proteins. The findings are published ahead of print in the Journal of Applied Physiology, and the study has been chosen as an APSselect article for October.   

“We believe our results highlight the importance of breaking up prolonged sedentary periods with brief ‘activity snacks’.” -Daniel Moore, PhD

Prolonged sedentary periods have been proven to impair the body’s ability to filter sugar from the blood following a meal but has unknown effects on amino acids. In this case, researchers studied 12 people (seven men, five women) across three trials for seven and a half hours each. Participants were subjected to prolonged sitting interrupted every 30 minutes by short bouts of walking or body-weight squats. The activity helped improve the efficiency of dietary amino acids used for muscle protein synthesis, the process to repair or replace old or damaged proteins. This is critical to ensure the body has an adequate quantity and quality of muscle.

A sedentary lifestyle is associated with loss of muscle mass. Therefore, “we believe our results highlight the importance of breaking up prolonged sedentary periods with brief activity snacks,” said Daniel Moore, PhD, co-author of the study. “We believe our results also highlight that moving after we eat can also make our nutrition better and could allow more dietary amino acids from smaller meals or lower quality types of protein to be used more efficiently.” 

Read the full article, “Walking or body weight squat ‘activity snacks’ increase dietary amino acid utilization for myofibrillar protein synthesis during prolonged sitting.” It is highlighted as one of this month’s “best of the best” as part of the American Physiological Society’s APSselect program. Read all of this month’s selected research articles. 

NOTE TO JOURNALISTS: To schedule an interview with a member of the research team, please contact APS Media Relations or call 301.634.7314. Find more research highlights in our Newsroom. 

Physiology is a broad area of scientific inquiry that focuses on how molecules, cells, tissues and organs function in health and disease. The American Physiological Society connects a global, multidisciplinary community of more than 10,000 biomedical scientists and educators as part of its mission to advance scientific discovery, understand life and improve health. The Society drives collaboration and spotlights scientific discoveries through its 16 scholarly journals and programming that support researchers and educators in their work.