What Is the Optimal Timing and Frequency of Workload-Matched Postprandial Physical Activity Breaks? A Randomized Controlled Crossover Study of Cardiometabolic and Cognitive Responses During Sedentary Behavior

The study investigated how the timing of physical activity after eating affects glucose levels, brain and muscle oxygenation, cognitive performance, and well-being during sedentary behavior. Twenty healthy adults (mean age 27.1 years, 12 females) consumed four standardized meals followed by four different regimens: sitting only, 15 minutes of cycling immediately after eating, 15 minutes of cycling 20 minutes after eating, or three five-minute cycling breaks during sitting. Results showed that cycling immediately after eating reduced glucose levels and improved brain oxygenation. All active conditions improved muscle oxygenation. Delayed activity and short breaks increased heart rate without cognitive or perceptual benefits. Physical activity immediately after eating proved most effective for reducing postprandial glucose elevation.