Exercise plays an influential role in managing blood sugar levels. That’s especially true of people with diabetes, which affects at least 38 million people in the United States.
Exercise improves your body’s insulin sensitivity so it uses glucose more effectively, helping you manage your condition. Exercise also helps with weight loss, a significant factor in reducing the risk of diabetes or, if you have diabetes, how much damage it can do.
At Keven Tagdiri, M.D. in Encinitas, California, we recommend exercise as part of a comprehensive approach to managing diabetes. Here’s how exercise can make a difference, along with tips to keep your blood sugar levels safe during workouts.
Physical activity helps lower blood sugar in a couple of key ways:
Regular activity increases your body’s ability to use insulin efficiently. This effect can last up to 24 hours after a workout, helping maintain steady blood sugar levels.
When you exercise, your muscles contract, allowing your cells to absorb glucose for energy even without insulin. Over time, consistent exercise can also lower your A1C levels (your average blood sugar over three months).
Not all exercise impacts blood sugar in the same way. How your levels change depends on the type, intensity, and duration of the activity, as well as your fitness level and heart rate.
Comfortably paced activities like walking, cycling, swimming, and yoga are excellent for lowering blood sugar.
Activities like sprinting, high-intensity interval training (HIIT), or competitive sports can cause blood sugar levels to rise. Stress during intense exercise, like a competition, can also raise blood sugar levels.
Stretching or gentle exercises may have little to no immediate effect on your blood sugar.
Understanding how your body reacts to different activities is essential so you can stay safe while benefiting from exercise.
To get the maximum benefit from exercise while avoiding any problems with your blood sugar, follow our advice:
Test your blood sugar before exercising. Levels between 100 mg/dL and 250 mg/dL are generally safe. If your blood sugar is below 100 mg/dL, have a small snack to avoid a drop during exercise, and don’t do a lengthy workout until your blood sugar reaches 100 mg/dL.
Check for ketones in your urine if levels are above 250 mg/dL. Ketones indicate your body is burning fat for fuel rather than sugar, which can lead to a dangerous condition called ketoacidosis in people with diabetes. Skip the workout if ketones are present.
You may not need to check your blood sugar levels during exercise for shorter workouts. For sessions lasting two hours or more, test every hour.
If your blood sugar drops below 70 mg/dL, stop and have a snack of 15–20 grams of fast-acting carbs, like a small piece of fruit or a granola bar. Retest in 15 minutes, and if it isn’t back to 100 mg/dL or higher, repeat the process.
Check your blood sugar when you finish. That helps you understand how your diabetes responds to exercise and if you need to eat. Have a snack if your blood sugar is below 100 mg/dL, and monitor your levels for up to 24 hours after a workout, as dips can happen later.
It’s easy to miss signs of low blood sugar during exercise since they can feel like a normal part of working out, such as sweating or fatigue. Pay attention to unusual symptoms, like blurred vision, confusion, lip or tongue tingling/numbness, and lack of coordination.
Because drops in blood sugar are a risk for people with diabetes, you should always have a fast-acting sugar source nearby when exercising. Options include:
Read the labels to ensure you’re getting about 15 grams of carbs.
To prevent lows, avoid working out during your insulin’s peak action time, skip alcohol before or after exercising, and stick to shorter, frequent sessions rather than one long workout.
Finish at least two hours before bed to reduce the risk of nighttime lows, and avoid hot tubs or saunas immediately after exercise, as heat can affect blood sugar.
Consider adjusting your routine if you frequently experience low blood sugar during exercise. Talk to us about modifying your insulin or medications, eating more before working out, and changing the type or duration of your activities.
Call Keven Tagdiri, M.D. today for expert advice on exercising with diabetes, or request an appointment online.
