Why are physical activity breaks more effective than a single session of isoenergetic exercise in reducing postprandial glucose? A systemic review and meta-analysis

The Effects of Accumulated Versus Continuous Exercise on Postprandial Glycemia, Insulin, and Triglycerides in Adults with or Without Diabetes: A Systematic Review and Meta-Analysis

“…Several studies [ 14 – 16 ] and reviews [ 17 – 19 ] have shown that multiple postprandial bouts of exercise elicit greater improvements to PPG levels compared to a single exercise bout, with some studies indicating that continuous exercise has a comparable [ 13 ] or superior [ 20 ] effect than accumulated exercise. It should be noted that the two commonly used accumulating exercise patterns in these previous studies were frequent brief bouts (e.g., 1–6 min) throughout the day at 20–60-min intervals (known as physical activity [PA] breaks, ≥ 5 bouts), and three short bouts (e.g., 10–15 min) timed around the main meals at 3–5-h intervals [ 18 ].…”

“…Previous systematic review and meta-analyses [ 17 , 19 ] have compared the acute effects of PA breaks and continuous exercise on glucose regulation, finding that when energy expenditure was matched, the former had a greater effect on glucose regulation than the latter. This result may be explained by one-bout exercise likely inducing glucose counterregulation, as evidenced by the elevated glucose levels during exercise compared to uninterrupted sitting [ 19 ]. Glucose counterregulation implies the physiological processes of increasing hepatic glucose output via counterregulatory hormones (e.g., glucagon and epinephrine) to prevent or correct hypoglycemia [ 22 ].…”

“…Glucose counterregulation implies the physiological processes of increasing hepatic glucose output via counterregulatory hormones (e.g., glucagon and epinephrine) to prevent or correct hypoglycemia [ 22 ]. However, studies with three short bouts (e.g., 10–15 min) of exercise timed around daily main meals were not included in these reviews [ 17 , 19 ].…”

Learning From Human Responses to Deconditioning Environments: Improved Understanding of the “Use It or Lose It” Principle

“…Risks associated with sedentary behavior can likely be mitigated by exercise (Tersa-Miralles et al, 2020 ; Farrahi et al, 2021 ; Gillen et al, 2021 ; Hatamoto et al, 2021 ; Peddie et al, 2021 ; Taylor et al, 2021 ), changing the behavior to breakup periods of sedentary behavior (Gouldrup and Ma, 2021 ), but certainly, as such behavior becomes more chronic and sustained, there is a risk for epigenetic alterations to the adaptations to inactivity that may pose risks for the reversibility and impact on conditions associated with aging and the impact of exercise (discussed in Barrons-Cabrera et al, 2019 ; Bagley et al, 2020 ; Rezus et al, 2020 ; Sellami et al, 2021 ). For many individuals, physical activity across the lifespan can likely impact the consequences of sedentary behavior and/or aging, possibly via the epigenetic influences of exercise or physical activity (Ling and Ronn, 2014 ).…”

“…However, improvements could be made by personalizing exercise for the individual as some people respond better to resistance vs. aerobic exercises (discussed in Sparks, 2017 ; Hart and Zernicke, 2020 ), and it is known that different types of exercise can elicit differing responses (Baptista et al, 2008 ) including myokine patterns (Gonzalez-Gils and Elizonda-Montemayor, 2020 ; discussed in Hart and Zernicke, 2020 ). Certainly, in the case of sedentary behavior, frequent bouts of activity have been found to be better than a single bout of intense activity (Gouldrup and Ma, 2021 ). In contrast, regular bouts of intense exercise may be advantageous as a general approach to modify development of adverse molecular changes (Sellami et al, 2021 ).…”