Moderate to vigorous exercise has traditionally been recognized as an effective tool for improving blood sugar levels. However, more recent evidence points to an additional factor: the time of day when physical activity is performed.
It appears that exercising in the late afternoon or evening may offer significant benefits for glucose regulation, even surpassing the benefits of exercising at other times. This finding is crucial for adults at risk for insulin resistance, a condition that precedes prediabetes and type 2 diabetes.
Why might evening exercise be more effective? The main hypothesis centers on how the body processes food and glucose. After eating, carbohydrates are transformed into glucose, which is released into the bloodstream.
In individuals with insulin resistance—common in obesity and metabolic syndrome—glucose has difficulty entering cells for use as energy. This is where exercise plays a vital role, acting as an insulin sensitizer and facilitating glucose absorption.
Experts suggest that evening or nighttime exercise is particularly beneficial because it can optimize the body’s handling of glucose during sleep. During the night, the body releases glucose to keep blood sugar levels stable. If insulin resistance is reduced through nighttime exercise, this glucose can enter cells more efficiently, rather than accumulating in the bloodstream.
Furthermore, circadian rhythms—our internal biological clocks—and daily fluctuations in insulin sensitivity may play a role. Evening physical activity may counteract the lower insulin sensitivity often observed at the end of the day, contributing to better glycemic control.
Another possible explanation, although not directly linked to exercise physiology, could lie in associated habits. People who exercise in the evening may adopt healthier eating patterns, such as eating dinner earlier or consuming smaller portions. However, this study did not delve into dietary habits.
Despite these promising findings, the fundamental recommendation for health remains: the best time to exercise is whenever possible. The key lies in consistency and finding a schedule that works for your routine.
Many patients with type 2 diabetes, for example, face challenges incorporating physical activity into their daily routines. Therefore, the overriding message is clear: any exercise is the most beneficial, and regular adherence to physical activity should be the priority to maximize its positive effects on health.