Why the Time of Day You Exercise Matters
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If you have type 2 diabetes, you already know how important it is to manage your blood sugar. You may also know that exercise is one of the best ways to do that. But did you know that the time of day you exercise can make a big difference?
A recent study found that people with type 2 diabetes had better blood sugar control when they did high-intensity exercise in the afternoon rather than in the morning.
What the Study Looked At
Researchers studied 48 people, including both men and women, with and without type 2 diabetes. Each person did a short session of high-intensity interval training (HIIT) on a stationary bike. Some did the session at 9 AM and others at 4 PM. The same people did both sessions, but at least a week apart.
To make sure food didn’t interfere with the results, participants followed a strict meal plan with fixed times and standard meals for three days before each session. They also wore continuous glucose monitors to track blood sugar throughout the day.
Morning Exercise Raised Blood Sugar
Surprisingly, the study found that when people with type 2 diabetes exercised in the morning, their blood sugar actually went up for two hours afterward. This happened in both men and women, but it was more noticeable in women.
In contrast, exercising in the afternoon did not cause a spike in blood sugar. This suggests that morning exercise may not be ideal for people trying to keep their glucose in check.
Why Afternoon Might Be Better
The researchers believe that higher levels of stress hormones and inflammation in the morning may explain why blood sugar rose after morning workouts. In particular, levels of cortisol—a stress hormone—were higher in the morning. Cortisol can raise blood sugar by telling your liver to release more glucose.
Markers of inflammation, such as C-reactive protein (CRP), were also higher in the morning for people with type 2 diabetes. These may make the body more resistant to insulin, making it harder to manage blood sugar after a workout.
Consistent Eating Patterns Help Too
Another key finding was that sticking to a regular eating schedule improved blood sugar control. During the three-day meal plan, people with type 2 diabetes had fewer ups and downs in their glucose levels. But when they went back to their usual eating habits, the benefits disappeared.
This shows that not just what you eat, but also when you eat, matters for blood sugar control.
What You Can Do
If you have type 2 diabetes, here are a few practical tips based on this study:
- Try to exercise in the afternoon, especially if you’re doing intense workouts. This may help you avoid post-exercise spikes in blood sugar.
- Stick to a regular meal schedule. Eating meals and snacks at the same time each day can help keep your blood sugar stable.
- Monitor how your body responds. Everyone is different. If you wear a glucose monitor, track how your levels react to different exercise times and foods.
- Talk to your doctor before making major changes to your routine, especially if you’re on medications.
Final Thoughts
Managing type 2 diabetes is not just about what you eat and how much you exercise—it’s also about timing. This study shows that doing the same workout in the afternoon instead of the morning can lead to better blood sugar control. And when you combine that with consistent meal timing, the benefits are even greater.
Small changes in your daily routine can make a big difference in your long-term health.