Running Regular: How to keep normal levels during intense exercise


Running Regular: How to keep normal levels during intense exercise

Summer is the season of increased exercise. From marathons to bike races, there is no shortage of intense, continuous exercise options available to the general population. However, for some there are certain restraints on participation in these types of activities like age, experience and injuries…but what about diabetes?

When you have diabetes, running long distances can be a fearsome obstacle. Intense continuous exercise can cause blood sugars to drop, even to hypoglycemic levels, or become too inconsistent to effectively manage.

However, if managed correctly, intense exercise like running a marathon doesn’t have to be such a daunting task for a person with diabetes. In fact, managing normal blood sugar during intense exercise may be easier than you think. For any diabetic, complete awareness of glucose levels before, during and after exercise is the key; knowing your levels at all times puts you in the position to prevent highs and lows before they happen.

While blood sugar can be irregular during intense exercise for any diabetic, type 1 diabetics need to prepare for it differently than type 2 diabetics. Consider using the following tips to manage your blood sugar while you’re pushing for first place in that marathon:

Just as many lifestyle changes need to be made when a person is diagnosed with type two diabetes, changes must also be made when they engage in intense physical activity. Unlike type ones, type two diabetics can still produce some insulin, which means they are less likely to experience bouts of hypoglycemia. Because of this, type two diabetics can use exercise as a way to lower their high blood sugar, lose weight and to become healthier overall. It is also important for type two diabetics to exercise for cardiovascular disease prevention and the improvement of insulin sensitivity and glucose control.

Though there are many benefits to exercise, there are still several things type two diabetics should keep in mind to stay healthy on the go:

  1. Before you begin any workout regimen, always make sure to check with your doctor for approval. Mention that you are a runner or intense athlete and ask for advice on diet and medication adjustments so as to prevent highs and lows during strenuous activities.
  2. Though it’s less likely, type twos are still at an increased risk for hypoglycemia during runs, and some diabetes medications can actually push blood sugar even lower during exercise. To prevent this, it is important to work with your doctor to make adjustments to your medications as needed.
  3. Be careful about taking supplements, power bars and energy drinks. While they can help prevent lows, their high caloric content can offset calorie-burn and the glucose lowering effects that occur during exercise, making weight loss more difficult. Consume these things only if you need them to maintain your energy during intense exercise.
  4. If you’re taking insulin to manage your type two diabetes, make sure to monitor your blood sugar levels as you exercise and adjust your insulin, meal times and the timing of your exercise appropriately to keep your levels regular.
  5. Time your workout strategically. Exercise positively affects your insulin sensitivity for as long as 72 hours depending on the intensity. For example, if you’re used to your blood sugar rising after you eat dinner, an evening run might be beneficial to keep your sugars from spiking. As a result, you’ll be less likely to have exercise-related low blood sugar.


Unlike type 2 diabetics who can make some insulin and therefore do not need to prepare as much for exercise, type one diabetics require a lot more planning because they are completely insulin deficient. This includes being extra careful about monitoring and logging blood glucose levels before, during and after exercise so you know what to expect in order to control it.

  1. Check with your doctor before you begin a workout regimen. They will be able to help you tweak your insulin and diet plan to fit with your performance goals.
  2. Always plan ahead; be one step ahead of your workout and your body by regularly monitoring your glucose levels. This way, you will know how your body will respond to intense exercise based on what you consume and how much insulin you take.
  3. When it comes to fueling your body, most intense runners require 30-60 grams of carbohydrates for every hour of exercise or 15-30 grams for every 30-60 minutes. However, some type one runners may need to plan their insulin and carbohydrate dosages differently depending on the length of the run, the intensity, the time of day, when the last meal was, and the body’s previous reaction to similar forms of exercise.
  4. Plan ahead for lows during exercise. Carbohydrate supplements are available for type one diabetics who need quick and easy ways to raise their blood sugar if it drops. Always carry a gel, sports drink, or fast-acting fuel like a honey packet to take if you feel low during a run.
  5. Make sure to drink water every 15 minutes or for every 25 grams of carbohydrates you consume during your workout. This will affirm your blood is flowing efficiently to distribute nutrients, and it keeps you hydrated.


During any form of exercise, it is important that diabetics keep their body fueled and ready to go. Highs and lows can be frustrating and turn good days into bad days. While all diabetics react differently to fuel, consider trying the following nutrition tips to maintain your levels.

  • Try to eat a carb-based meal or snack up to three hours before exercise.
  • Carry quick carbohydrate snacks with you for to eat whenever you are feeling low (such as hard candy, granola bars, dried/fresh fruit, crackers, trail mix, etc.). If your workout will be longer than an hour, be sure to plan a snack break in.
  • If your activity is going to last all day, try to eat at least six small meals with carbohydrates and protein throughout the day.
  • Drink lots of water
  • Eat after exercise to prevent hypoglycemia and to restore glycogen levels


  • Never start exercise if your blood sugar levels are above 300 mg/dl or below 70 mg/dl.
  • Always make sure to let your coach/teammates/workout buddies/trainer/etc. know that you have diabetes and how to recognize blood sugar lows so they can help you in case of hypoglycemia.

Diabetes does not have to limit you from accomplishing goals like competing in a triathlon or simply going on long runs after dinner. While everyone’s levels respond differently to exercise, there are many different things to try in order to keep your body regular and healthy. The key is to monitor your levels carefully, adjust your fuels and workouts accordingly, and don’t let your diabetes stand in your way of conquering your goals.
AMA Citations:

Nutrition for athletes with diabetes. Cleveland Clinic Web site. Accessed July 9, 2014.

Nisevich Bede P. Running withy type 2 diabetes. Runner’s World Web site. Published June 17, 2013. Updated 2013. Accessed July 9, 2014.

Nisevich Bede P. How to fuel a long run with type 1 diabetes. Runner’s World Web site. Published July 23, 2013. Updated 2013. Accessed July 9, 2014.