Exercising like crazy can have a significant impact on lowering your blood glucose levels. When you engage in physical activity, your muscles use glucose for energy which helps to reduce the amount of sugar in your bloodstream. However, the exact amount that exercising like crazy can lower your blood glucose levels may vary depending on several factors.
Become familiar with how your blood glucose responds to exercise. Checking your blood glucose level more often before and after exercise can help you see the benefits of activity. You also can use the results of your blood glucose checks to see how your body reacts to different activities.
Factors that influence how much exercise lowers blood glucose
It’s not uncommon to wake up to a high blood sugar reading, even if your number was in the green zone when you went to bed. You may be experiencing the “dawn phenomenon,” which occurs when the body preps for waking up by releasing cortisol and other hormones, between 2 and 8 a.m., according to the Mayo Clinic. Learning more about what happens before, during and after you get active can also help to ease some of this worry. To support you with this, we’ve put together information about the steps you can take to try and manage the effects of exercise on your blood sugar level.
If you do have low blood sugar after exercise, eat a small snack that has carbohydrates. For example, you could have fruit, crackers or glucose tablets. Or you could drink a half-cup (4 ounces/118 milliliters) of fruit juice. Any time is better than never, but new research suggests you can score even more blood sugar benefits by carving out time to sweat during this time of day. My wife, having the same nutrition, has prediabetes (normal insulin levels), at least a month ago she had.
For some people, blood sugar can rise in the morning — even before breakfast — due to changes in hormones or a drop in insulin. One option is a continuous blood glucose monitor, which can alert you to highs and lows. Another way that exercise can increase blood sugar for a time is more complex, and it has to do with the availability of insulin in your system. If you’re short on insulin, your body can’t move sugar from your blood into the cells where it’s needed.
Glycolysis can only provide enough energy to muscle cells for about one minute of contraction. BG spikes caused by bursts of adrenaline can be hard to anticipate, as they happen most often smack in the middle of a an exercise session. This means that rather than treat the spike immediately, you most likely will need to wait and take additional insulin after the fact.
- The intensity and duration of the exercise
- Your current fitness level
- Your body’s response to exercise
- Whether you have eaten before exercising
- Your overall health and any underlying medical conditions
Exercise lowers blood glucose for 24 hours or more by increasing insulin sensitivity. High-intensity or prolonged exercise can cause a short-term increase in blood glucose. At rest and during low-intensity exercise, skeletal muscle preferentially burns fatty acids using aerobic metabolism. As exercise intensity increases, skeletal muscle switches to using glucose for energy, as glycolysis is a faster process that doesn’t require oxygen. Regular exercise is a cornerstone of healthy living and managing diabetes. Yet the conversation around exercise with diabetes is often filled with angst.
Unfortunately, there are no hard and fast rules for making these insulin dosing adjustments. Each situation for each person will require an individualized response. It’s best to work with your medical team to determine the best response for you.
FAQs about how exercise affects blood glucose levels
- How long does it take to see a decrease in blood glucose levels after exercising?
- Can exercising too much cause low blood sugar levels?
- What is the recommended amount of exercise to lower blood glucose levels?
The effects of exercise on blood glucose levels can be seen immediately after finishing a workout. However, the most significant drop in blood sugar typically occurs within 1-2 hours post-exercise.
Yes, excessive exercise can lead to hypoglycemia (low blood sugar) especially if you are taking insulin or other medications that lower blood sugar levels.
Aim for at least 150 minutes of moderate-intensity aerobic exercise per week, spread out over at least three days, to help improve blood glucose control.
