It can be a true challenge to keep your glucose levels stable during exercise, and many avoid regular exercise due to fear of getting hypo. Here are some solid tips on how to prevent those uncomfortable high’s and low’s during exercise.
Written by diabetes coach Hildegunn Fossheim
The benefits from regular exercise is well known to us all: better health, better sleep quality, better memory, better mood, more energy, and less stress – the list is endless. And for you with diabetes exercise results in some extra positive effects that is hard to turn down. It can lower your glucose sugar, improve insulin sensitivity, and give better blood sugar control – the dream results for every diabetic right?
During the exercise, on the other hand, it can be a true challenge to keep your glucose level under control. It isn’t particularly comfortable to work out with either too high or too low blood sugar, and many avoid exercising due to fear off getting hypoglycemic.
Yet, most things here in life are possible by adapting your own experience, good tips and planning. There is no reason for people with diabetes not to exercise, on the contrary. It’s about finding a balance that works for you, and it differs from person to person – just like diabetes. There is still some advice that can be adapted by most. Below are some solid tips on how to prevent those high’s and low’s during exercise.
Your blood sugar’s response to exercise will vary depending on:
- Blood sugar level before you start exercising
- the intensity of your workout
- how long you are active
- changes you made to the insulin dose
- Measure regularly
If you’re planning a workout later in afternoon it’s wise to check your blood sugar more often during the day. This way you know your starting point, and can make necessary adjustments troughout the day so you can avoid an unstable glucose level during the exercise. Strategic monitoring and insulin calculation is essential to get the optimal benefit from your exercise.
- Optimal glucose level
You will get the most out of your exercise if your blood sugar is between 5 mmol and 10 mmol of the last hours before exercise. These levels will also benefit your blood sugar after the activity.
- Avoid fast-acting insulin
Don’t exercise right after a meal where you have injected fast-acting insulin. The effect of the insulin is than on its way up, and it’s easier to get hypoglycemic without warning signs.
- Measure right before
Measure your blood sugar right before exercising, so you know if you have to take preventative measures.
- Low = half a banana
If your glucose level is too low (below 5 mmol) it can be wise to eat a small snack, such as half a banana before exercising.
- High = wait
Don’t exercise with a very high blood sugar level (above 15 mmol), it’s not comfortable and it can harm your physical performance. If your blood sugar is very high, you should correct the level before exercising. Wait for a little half hour or so, watch the blood sugar, and if it’s lowered you can continue as planned.
- Changes in insulin dosage
In my lectures I constantly give following advice to health professionals:
For people who exercise actively the insulin doses of fast-acting insulin, to the last meal before exercising should be reduced by 30% in moderate activity and 50% at high activity. If you know your exercising the day after many will benefit from reducing it’s long-acting insulin by 10-20%. Each time I say this some eyebrows are raised among the crowd. This is probably because most health professionals don’t live with diabetes themselves. Doctors will always actively try to push down your HbA1c value, and are schooled to think that the solution to reduce a high HbA1c is to take more insulin. Personally, I have repeatedly experienced with my patients that by reducing insulin doses, especially in relation to training, the HbA1c value has decreased. This is because most are compensating with insulin doses after hypos, and therefore get a high blood sugar afterwards.
- Carry carbs
Always keep a small carbohydrate snack, like a banana, glucose tablets or a fruit drink, on hand in case you blood sugar gets low.
- Check your blood sugar
If you’re going to work out for more than an hour, check your blood sugar levels regularly during your workout, so you’ll know if you need a snack.
- Frequent sips
If your going to work out for a long time where you’re dependent on getting your blood sugar fast back up, a tips is to bring strong juice. Take a sip every 10 minutes so your blood sugar stays relatively steady.
- Drink water
If you exercise for more than 30 min. you should drink water along the way to prevent dehydration. Drink also plenty of water before and after exercise.
- Insulin Pump
If you use insulin pump reduce the basal rate by 50-60% during exercise.
- Exercising alone and worried about hypos?
Your aren’t alone in this. I constantly hear from my patients that fear of hypoglycemia prevents them from exercising, especially alone. Personally, I would do as so many others with insulin-dependency: I would install the DiabetesGuard app on my phone and is diligently when exercising. The safety app is extremely useful and completely free to use.
You set an alarm for how long you plan to be active, and select the people you want to be contacted if you can’t turn off the alarm. If you get a hypo during, let’s say, during a run and you therefore can’t turn off the alarm it automatically alerts the people you added with the message that you need help. Once they confirm that they can help you they get the SMS with your current GPS position.
Many are afraid to bother others by using the alarm, but I can promise, as a type 3 (married to a man with diabetes) there is a big comfort to know that your loved is safe, and that I get alerted if he isn’t.
- For many, it will be helpful to reduce the insulin to the meal after training, by 20-30% because the need for insulin during and after physical activity is impaired.
Check your blood sugar after exercising so you know how your body is reacting to the measures you have done before and after exercise. Use this knowledge to the next training day, and it can help you keep your blood sugar from going too low or too high.
If you want to know more about how to regulate insulin to your meal, I recommend reading this article about “how to find the right meal dose?”. Use this method and subtract the procent prior training.
What do you do to keep your blood sugar stable during exercise?
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