People with type 1 or type 2 diabetes can benefit from exercise. The risk of heart disease and death is reduced by exercising.
However, exercise can cause hypoglycemia, or low blood sugar, especially in people with type 1 diabetes and, less commonly, in people with type 2 diabetes who use insulin.
Low blood sugar and the fear of going low can be barriers to exercise participation. Reducing the amount ofinsulin used before and after exercise can help reduce the occurrence of low blood sugar.
Your body can use the energy from the glucose in your body. Your body takes blood sugar from you to rebuild the stores. You will need lessinsulin during and after activity because you are more sensitive to it.
The impact on blood sugar and insulin sensitivity is influenced by the type, intensity, and duration of activity.
- Aerobic exercises decrease blood sugar levels.
- Longer duration of exercise can result in increased blood sugar use and increased risk of hypoglycemic events.
- Resistance or high intensity exercises can cause your blood sugar to go up.
- A session of moderate aerobic exercise with short bursts of high intensity can lead to less risk of hypoglycemia and better stability of the blood sugar.
“During and after exercise, low blood sugar can occur. If you use multiple daily injections, you can reduce your daily dose in the morning before you exercise. If you use an injection pump, you can stop it at the start of exercise. It is important that you don’t suspend it for more than 90 minutes.”
Another option is to reduce your basal rate 30 to 60 minutes before exercising and continue until after you complete your exercise.
You may also need to reduce your bolus, or mealtime, insulin. If you plan to do mild to moderate aerobic exercise within 2 to 3 hours after your mealtime insulin, you may need to decrease that insulin by 25 to 75 percent based on how long you plan to exercise.
“If you plan to do long-term high intensity or aerobic exercise, healthcare professionals don’t recommend an adjustment.”
You can talk to your doctor about how to adjust your dose ofinsulin.
It can help if your pre-workout blood sugar is between 90 to 250 milligrams/deciliter (mg/dl). If your blood sugar is less than 90 mg/dl, ingest 15 to 30 grams (g) of a carbohydrate about 15 to 30 minutes before exercise. Choose a type of carbohydrate that your body can absorb quickly, such as:
- The tablets haveglucose.
- Hard candy.
- There is fruit.
- There is fruit. juice
You can repeat it every 30 minutes if you have a repeat blood sugar test. Exercising for less than 30 minutes may not require an additional intake of calories.
If your blood sugar is high, you should check your urine for ketones. If ketones are present, do not perform any exercise. Wait to exercise until you have no ketones in your urine.
You can do mild to moderate intensity exercises if there are no ketones. High intensity can make hyperglycemia worse.
High intensity workouts can raise your blood sugar levels. The release of stress hormones such as cortisol and adrenaline, as well as other counter regulatory hormones such as glucagon, which raise blood sugar by stimulating your liver to release glucose, is what is causing this. Your blood sugar may be high after you work out.
“It is important to not give a correction dose during your workout. You can drink water or do a light aerobic activity after you finish. If this doesn’t work, you can give correction, but half of what you would give for the same blood sugar level.”
If you work out more than you planned, you could be at risk for hypoglycemic symptoms. Try to check your blood sugar during exercise. If your blood sugar is less than 90, you should have a snack with 15 to 30 grams of carbs.
If your blood sugar is less than 70, you may have symptoms of hypoglycemics. If you have low blood sugar, stop exercising and treat it. Do not restart your exercise until you have a normal blood sugar.
Hypoglycemia occurs when your blood sugar is less than 70. The only way to know if you have symptoms is to check your blood sugar. Some early symptoms include:
- I felt shaky.
- Increasing heart rate.
You may experience a drop in blood sugar.
- Is it anxiety or is it irritability?
- It is too sleepy.
- slurred speech
- blurred vision
There can be, with severely low sugar, less than 40 percent.
- There is confusion.
- Loss of consciousness.
If you have low blood sugar, you should treat it. The rule is used to treat mild to moderate hypoglycemics. 15 g of Carbohydrates and 15 minutes to test blood sugar. If the blood sugar is less than 70, you should repeat the process.
Low blood sugars are life threatening. If you are unconscious or need to raise your blood sugar, you can call the emergency number.
After you complete exercise, your blood sugar can go down for several hours. During intense activity, muscles need to replenish their glycogen stores. You can help prevent low blood sugar by eating a snack that absorbs slowly, such as a trail mix.
You may need to reduce your dose of the drug.
A small 2013 study found that decreasing the bolus dose of insulin by 50 percent at the meal following exercise helped to prevent early-onset hypoglycemia up to 8 hours after exercise.
If you use multiple daily injections, reducing basal insulin by 20 percent that day can help prevent low blood sugar. If you use an insulin pump, decreasing your basal rate by 20 percent for 5 to 6 hours after exercise can reduce your risk of going low during the night.
There are many factors that can affect your dose adjustments. You can talk to your doctor about how to adjust your blood sugar levels after exercising.
If you exercise at night, especially after you eat dinner with the usual dose ofinsulin, you can be at an increased risk of low blood sugars overnight.
If you have a lifestyle that involves exercise and eating, you can reduce your risk by decreasing your eveninginsulin doses and having a snack after exercising.
Dr. Kelly Wood is an ABMS board certified endocrinologist and internal medicine physician who treats adults with diabetes, thyroid disease, osteoporosis, and other hormonal conditions. She achieved her fellowship in endocrinology from University of Wisconsin Hospital and Clinic