a woman running during sunset
Earlier this fall, we learned that walking after meals for just two minutes (yes, really!) can have a substantial impact on blood sugar. But beyond sprinkling in little activity “nuggets” as dessert, researchers are still on a quest to learn more about the best methods, times of day and intensity levels of exercise that might affect—and potentially help us better manage—our blood sugar levels.
While you might think this only matters for people who have diabetes or are at a higher risk for it, blood sugar is actually important for all humans to keep even-keeled. It’s normal for all people to have our blood sugars rise and fall throughout the course of the day. Under normal conditions, our bodies are able to allow sugar from the blood into our cells, returning blood levels into a normal range. When blood sugar levels are high, our pancreas secretes insulin, which alerts our bodies to soak up the glucose in the blood to use as energy now or store in the liver as glycogen for fuel later. This process lowers the amount of sugar in the blood. Not to mention, a fairly steady blood sugar level is beneficial in maintaining balanced, sustained energy levels from morning to night.
For individuals with prediabetes or type 2 diabetes, insulin resistance can alter the body’s response to blood sugar; cells stop responding to the insulin, and glucose will stay outside of cells. As a result, blood sugar remains high. With about 1 in 10 Americans now diagnosed with type 2 and another 38% fitting the criteria for prediabetes, according to the Centers for Disease Control and Prevention estimates, scientists are eager to discover more about the best ways to make the blood sugar roller coaster an easier and smoother ride.
A new study published November 1, 2022, in the journal Diabetologia adds a fascinating piece of evidence to that exercise aspect we mentioned earlier. Apparently, the “what” (exercise) makes a difference, as does the “when.” Getting physically active in the afternoon or evening, ideally between noon and midnight, may significantly decrease insulin resistance and may be better at helping to control blood sugar than A.M. exercise.
Read on for more about this new health study, and to discover other ways to balance your blood sugar.
Related: What You Need to Know About Physical Activity and Diabetes
What This Blood Sugar Study Found
The Netherlands Epidemiology of Obesity study is a database of adults aged between 45 and 65 with a body mass index of 27 or greater. (Before we go any further, take note that BMI’s validity and relevance as an indicator of health is being called into question, but since they used to determine eligibility for this study, we wanted to mention it.)
For this research, scientists invited all participants with a body size that was representative of their area in the Netherlands to be part of a control group; this ended up resulting in 6,700 participants. All of these individuals had a physical exam, which involved blood sugar samples that tabulated blood glucose and insulin levels while fasting and after eating. They also completed questionnaires about lifestyle factors, and some had their liver fat content measured via an MRI.
From this group, the researchers randomly selected 955 people to wear an accelerometer and heart rate monitor for four days and nights to track activity levels and overall movement patterns. To categorize exercise timing, the scientists separated the day into six-hour blocks:
6 a.m. to noon
Noon to 6 p.m.
6 p.m to midnight
Based on the activity trackers, the scientists sorted each participant into one of those blocks based on when they racked up the most moderate-to-vigorous physical activity. At the end of the data-gathering, 755 participants were included in the analysis.
Related: These Are the 5 Best Exercises for Your Health, According to a Harvard Doctor
Those who exercised in the afternoon experienced an 18% decrease in insulin resistance, and activity in the evening was correlated with a 25% reduction in insulin resistance. Activity spread throughout the day or activity only performed in the morning appeared to have no impact on liver fat content and insulin resistance, while afternoon and evening physical activity did.
In addition to the impact of insulin on blood sugar control, the other way glucose can enter cells is through exercise. Muscles require energy when we move and challenge them. To power us enough to complete the tasks we’re asking them to do, our bodies allow glucose to slip into muscle cells.
The scientists admit that it’s too early in the information-gathering process to explain exactly why afternoon and evening exercise showed better results than exercise in the morning. They also have yet to prove if shifting exercise timing from morning to afternoon or evening will improve activity, or if there is something else about those who have that P.M. habit that might be moving the needle.
The Bottom Line
This new study found that afternoon and evening exercise might provide the biggest benefits to blood sugar control. While this is interesting to keep in mind, it’s vital to note that this is just one study, and a fairly small one, at that. Larger, more diverse research is required to validate these findings. Plus, the most important moral of the story is that activity ANY time of day is beneficial. In fact, morning exercise might actually be your best option if you find it challenging to make exercise a part of your daily routine. (Translation: Early birds, keep up the great work if you’re loving that 6 a.m. yoga class or walk!)
Keep in mind that exercise is just one of many healthy ways to lower your blood sugar. Sleep, hormones, medicine and other sneaky factors can impact blood sugar as well. What’s on our plate makes the biggest impact, of course, so we recommend sprinkling these 29 recipes to help keep blood sugar in check into your meal plan, too.
Up Next: These Are the Fastest Ways to Stabilize Your Blood Sugar If You Have Diabetes