Managing Blood Sugar

on the Run

Managing Blood Sugar on the Run

Exercise affects blood sugar—here’s how to keep it in check if you have diabetes.

Physical activity lowers blood sugarBlood sugarOr blood glucose. The main sugar (glucose) found in the blood, and the body’s main source of energy., right? Actually, it’s not quite that simple, especially for people with type 1 diabetes.

In reality, blood sugar can go down or up during and even after physical activity. Everyone’s body responds a little differently, but in general:

low blood sugar high blood sugar
  • Low blood sugar (hypoglycemia) from physical activity most often happens to people with type 1 diabetes who exercise for long periods or who work out hard without adjusting their insulin dose or meal plan
  • High blood sugar (hyperglycemia) can happen to people who perform very high-intensity (anaerobic) exercise like biking hard

It’s not always possible to know how your blood sugar is going to react to different activities. Some change is unavoidable, but the key is to keep your blood sugar levels from going too high or too low. Be sure to speak with your doctor about how to handle low and high blood sugar situations.

Avoiding LOWS during and after physical activity

watch the clock during activity eat before and after activity - apples and nuts
  • Watch the clock. Blood sugar levels can go too low if you’re active for long periods
  • Eat something first. Being active on an empty stomach can cause low blood sugar
  • Plan for your insulin and food needs. This may take some trial and error as well as the help of your diabetes care teamDiabetes care teamYour diabetes care team may include: a primary care doctor, a diabetes and hormone doctor (endocrinologist), a registered nurse, a diabetes educator, a dietician, a heart doctor (cardiologist), a foot doctor (podiatrist), an eye doctor (ophthalmologist/optometrist), a kidney doctor (nephrologist), a dentist, a pharmacist, and a mental health professional. . But adjusting the insulin dose and food intake to the level of activity you plan can help keep your blood sugar in a safe range
  • Stop if you feel any warning signs of low blood sugar. Just going “5 minutes more” can be dangerous. Take a moment to eat or drink some kind of high-carbohydrateCarbohydrateCarbohydrates are the main kinds of food that raise blood sugar levels. Your digestive system changes carbohydrates into glucose (sugar), and then uses this sugar as a source of energy for your cells.

    There are 3 main types of carbohydrates in food: starches (complex carbohydrates), sugars (simple carbohydrates), and fiber. Fiber is the part of plant foods, including fruits, vegetables, and nuts, that you can’t digest.
    food if you feel like your blood sugar is low
  • Keep “emergency carbs” close at hand. Always keep some form of high-sugar food handy. This can be a soft drink (non-diet), fruit juice, glucose tablets, raisins, or hard candy
  • Monitor later, too. Blood sugar levels can drop even 16 to 24 hours after physical activity because the body uses blood sugar to replace sugar that has been used by the muscles

Avoiding HIGHS during and after physical activity

  • Make sure not to start out too high! A high blood sugar level can go even higher because of exercise
  • Match insulin dose to activity intensity. Blood sugar levels can also go too high if physical activity is too intense and/or insulin levels are too low
  • Check for ketones. If blood sugar is too high, the body might produce ketonesKetonesOrganic compounds produced when the body breaks down fats and fatty acids to use as fuel. This is most likely to occur when the body does not have enough sugar or carbohydrates or the body cannot use sugar effectively. Because high levels of ketones are dangerous, a urine test is one way to check the level of ketones in your body. and a dangerous condition called ketoacidosisDiabetic ketoacidosis (DKA)DKA is a condition that occurs when there is a lack of glucose in the body and a buildup of ketones in the blood. Ketones are made when the body uses fat for energy instead of sugar. This can happen when the ratio of glucose to insulin in the body is improper, so your cells don’t get the sugar they need to use for energy. can result. So, if your blood sugar is unusually high for you, check for ketones, too!
  • Going for the long haul? You may need to eat during or after physical activity if the workout is very intense or continues for a long time. A low‑fat snack that has 15 to 30 grams of carbs may help
  • Know which way blood sugar is going. Start checking 90 minutes before starting an activity. If the blood sugar level is going down (even if it is still in a safe range), a snack may keep it from going any lower. This is really important when starting an activity where it will be hard to pause for a blood sugar check
  • Planning for longer activities. When longer periods of physical activity are planned, it's a good idea to have a pre-exercise snack that includes fast-acting carbohydrates. This can include juice or glucose tabs. However, it may be better in some cases to decrease insulin doses for planned activities, rather than increase calories. Always check with your diabetes care team before adjusting insulin doses

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Sometimes it’s okay to have candy or a little sugary soda?


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Emergency carbs like these are good to have on hand in case you experience low blood sugar.

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