Tips for Healthy and Safe Activity with Type 1 Diabetes

Physical activity is a cornerstone of healthy living and offers significant benefits for people with diabetes, including improved insulin sensitivity, cardiovascular health, and mental well‑being.

Exercise also presents unique challenges in managing blood sugar levels. For people with type 1 diabetes, balancing insulin, food, and physical activity is essential — even during light activity such as housework.

This video covers what you need to know.

During aerobic activities, like walking, running, or swimming, muscles use glucose for energy, which can lead to a drop in blood sugar both during and after activity.

Anaerobic or high-intensity activities, like sprinting or weightlifting, may raise blood sugar at first, due to the release of stress hormones, but then there’s a delayed drop.

The risk of hypoglycemia is highest during and after moderate to prolonged aerobic activity and may persist for several hours, even overnight. Hypoglycemia is when blood glucose dips below 70 mg/dL.

People at highest risk or hypoglycemia are those who:

• Use higher insulin doses without adjusting for activity
• Engage in prolonged or unfamiliar types of exercise
• Have a history of hypoglycemia unawareness
• Don’t monitor their glucose closely before or after physical activity

Follow these tips to keep your exercise routine safe and healthy for type 1 diabetes:

• Eat snacks that include protein if your exercise will last longer than 1 hour.
• Check blood sugar before and after exercise — and in the hours following exercise, too.
• Carry fast-acting carbs, like glucose tablets and juice, with you. If your pre-exercise glucose is low — less than 100 mg/dL — eat 15 grams of fast-acting carbs.
• If blood sugar is high — over 250 mg/dL — check for ketones. If ketones are high, follow medical advice from your healthcare provider. If only trace or no ketones are found, it’s usually safe to proceed with exercise.
• Finish workouts at least 2 hours before bedtime to reduce the risk of nighttime lows.

You may be able to reduce your chances of developing exercise-induced hypoglycemia if you:

• Use a continuous glucose monitor, called a CGM, or flash glucose monitors for trend detection and alerts
• Adjust your basal or bolus insulin according to timing and intensity of your exercise
• Take 15 to 30 grams of fast-acting carbs if your glucose is lower than normal or trending downward
• Keep glucose tablets or snacks available during longer or unexpected activities
• Maintain an activity and glucose log to identify patterns so you can create strategies that work for your lifestyle and your body.