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Exercising in the Heat: Tips to Keep you Safe

Warmer weather may have you feeling motivated to get outside and be more physically active. For those of you who have “fallen off the ‘exercise’ wagon” during the winter months, spring and summer are a great time to get back on track. This often involves being outdoors more, if that’s the case, then please keep the following safety tips in mind:

Stay well hydrated

  • Staying hydrated is imperative, especially went it is hot outside. Fluid losses (from sweating), during exercise, increase with rising temperatures and humidity.
  • If your diabetes is poorly controlled, you will be at greater risk of becoming dehydrated, as chronically elevated blood sugar levels will increase urination thus increasing fluid loss.
  • Dehydration negatively impacts exercise performance.
  • Some of the symptoms of dehydration can be mistaken for hypoglycemia, such as fatigue and feeling light-headed.
  • Inadequate fluid intake that leads to dehydration can result in temperature dysregulation, cardiovascular dysfunction, and heat stroke.
  • Dehydration can also result in hyperglycemia (this is a vicious cycle as hyperglycemia will further increase fluid loss from increased urination)
  • To help you stay well hydrated when exercising outside in the heat and humidity, keep the following tips in mind:
        1. Don’t count on thirst alone
        2. Weigh yourself before and after exercise. If you are adequately hydrated, pre-exercise weight and post exercise weight should remain the same.
        3. Look at your urine, “pale and plentiful urine generally indicates the athlete is hydrated; dark and sparse urine is an indication that more fluid is required. “
        4. Start increasing fluid intake a few hours before exercise
        5. Aim to drink 1.5 to 2.5 cups of carb free fluids 2 hours before the start of exercise.
        6. Sip on small amounts of fluid throughout the duration of exercise. Drinking large amounts of fluid at once may cause stomach upset. Carb free fluids, such as water, is usually best.
        7. If exercise lasts more than 1 to 2 hours a sports drink that contains both carbohydrates and electrolytes may be necessary. Make sure to discuss this with your physician or diabetes educator. *See information on hypoglycemia (below) for more information.
        8. Continue to replace fluid losses following exercise.

    Keep medication safe

    • Keep all oral and injectable medication out of direct sunlight and in a cool and dry place.
    • Medication that has been exposed to temperature extremes may lose its potency.

    Keep skin safe

    • Don’t forget to apply sunscreen regularly. Sunburn can contribute to hyperglycemia as it is a stressor on the body.

      Reduce risk of hypoglycemia

      • “Exercise induced hypoglycemia is common in people with type 1 diabetes and to a lesser extent, people with type 2 diabetes using insulin or insulin secretagogues”
      • Hypoglycemia can occur during, after, and up to 48 hours after exercise as insulin sensitivity is increased and muscle glycogen stores are replenished.
      • Those who treat their diabetes with insulin or an insulin secretagogue may reduce hypoglycemia risk by monitoring blood glucose during exercise and more frequently following a bout of exercise.
      • Insulin adjustments and/or extra carbohydrate may be required to prevent a low blood sugar. This should be discussed with your physician.

    This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

    1. Hibbert-Jones E, Regan G. (2012). Exercise and Sports in Diabetes. Retrieved from
    2. American Diabetes Association Professional Practice Committee. Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care. 2016, 39: (S 2065- S 2075).