Diabetes exercise and workout
Diabetes and exercise is a topic of its own, and sometimes managing blood sugars around exercise and activity turns out to be more challenging than the workout itself.
On the one hand, it’s hard because your body reacts completely different depending on the time of day and how fit you are. And on the other side, it’s hard because your blood sugar behavior varies depending on what kind of exercise or activity you’re doing. But exercise is so good for you that it’s worth the trouble. It’s a surprisingly powerful tool in your diabetes toolbox.
What effects does exercise have on the body
Exercise has significant impacts on the body, the types of which often vary based on activity.
Power sports (anaerobic)
In anaerobic sports (for example, lifting weights, climbing, volleyball, tennis, sprinting (i.e., mostly stop-and-go sports)), blood sugars may stay stable or even go up, and then fall again afterward while you’re recovering. Anaerobic exercises are usually brief, intense bursts of physical activity where the oxygen demand surpasses the oxygen supply. The cells can’t go through their usual ways of getting the energy to perform whatever the action is (lifting weights, sprinting, etc.). In situations like these, adrenaline rushes in to help which causes sugar stores in the muscles to dump their load. You can already guess what happens next – your blood sugar rises quickly. This is especially common in competitive situations. Some athletes with diabetes take a little bit of fast-acting insulin to stay on track here.
Endurance sports (aerobic)
In aerobic exercise (for example, jogging, walking, swimming, cycling), blood sugar usually drops, both during and for a long time after. You can often do aerobic exercises for more extended periods of time (10-minutes or more). They are usually rhythmic and repetitive and will increase your heart rate and breathing. Here, your body is burning oxygen along with glucose stores or fat to supply the energy you need.
For exercise newbies and those getting back in shape, low-intensity steady workouts are ideal, since your body will use fats as the primary energy source, and burn sugar reserves at a slower pace. This lets you last longer and also reduces the hypo risk. With increased intensity and duration, more glucose is used, and your risk for low blood sugars also increases.
The more often you exercise, the more efficient your muscles will get at using energy, and the better it will get at using fats for energy. Additionally, the glycogen store in your muscles (200-300 g) gets bigger the more you use it. So you can expect that at the beginning of a new activity, you’ll have to be more aggressive with planning and precautions than you will once your body gets used to it.
After exercising, while you’re recovering and basking in the glow of doing something great for yourself, the work for your body is just getting started. Especially after any endurance exercise, your glucose stores will be empty and hungrily snatch up any sugar floating through your bloodstream for the next 7-11 hours. It might feel like your insulin is supercharged, and you need to stay mindful of lows.
For extreme events, like a marathon or a weekend sports tournament, it may take several days until things are back to normal. This is partly due to small insulin-independent transporters that help shovel sugar into the cells to replenish the sugar stores in your muscles and liver. Did you catch that? Those special transporters work even without insulin! That’s part of what makes exercise so cool!
What staying active does for people with diabetes:
- Quality of sleep
- Heart health
- Insulin sensitivity
- Weight loss
- Glucose production from the liver
- Circulating insulin
- Joint pain
- Blood pressure
How to overcome exercise resistance
“I’m too old.” “I’m too overweight.” “It’s just not worth the effort.” Have you ever used these excuses not to exercise? You’re not alone. But the benefits of getting active include more energy, reduced blood sugar levels, weight loss and more—so it’s time to stop talking yourself out of it and start moving!
In his book, Diabetes Burnout: What to Do When You Can’t Take It Anymore, Dr. William Polonsky explains seven ways to overcome exercise resistance:
- Make it fun. “Search for activities that are fun, enjoyable or rewarding for you—especially if exercise seems boring or you haven’t been able to stick with an exercise program,” says Dr. Polonsky. Think about what you like to do—walking the dog, swimming laps—and then try a different activity each week to avoid boredom.
- Make it convenient. If the health club is a 20-minute train ride away, it will be easier to talk yourself out of going. Make your activities as convenient as possible (like finding a gym closer to home) or try other activities on those days when you don’t feel like making the trek (like walking around your block).
- Make it reasonable. If you’re just getting started with an exercise program, don’t set your goal too high. Create small goals for yourself so you enjoy early successes and stay motivated.
- Make sure you test. Dr. Polonsky explains, “If there is one single thing that can encourage people to keep exercising, it is seeing concrete, positive results from their own efforts.” Test your blood sugar before and after exercise to see the positive results for yourself.
- Make it an activity for two (or more). Everything is more fun with a friend! Not only will the time fly, but you can encourage each other to keep going.
- Make it safe. “Seek out professional advice—especially if you think exercise will cause your blood glucose to go too low or give you too much pain and discomfort,” advises Dr. Polonsky. Before you begin, talk with your doctor or even an exercise physiologist to devise a plan that works for you.
- Make it positive. Don’t allow yourself negative thoughts, like you’re too old, too overweight, or it doesn’t work anyway! “No matter how disappointing your past experiences may have been, the truth is that there is no one on this planet who is too old or too overweight to exercise,” says Dr. Polonsky.
Remember, becoming more active is something everyone can do. One step at a time is all it takes.
How to work out with diabetes
If you're new to exercise, or if you have additional health issues, check in with your healthcare provider before you begin.4 Think twice if you've had low blood sugar in the past day or ketones are elevated.5 We want you to be healthy, but even more important, we want you to be safe.
Know your numbers before you work out
You need to know your numbers before beginning your workout. Blood sugar levels could vary, so make sure you take your doctor’s recommendation on what fitness plan might be best for you and what your ideal blood sugar levels should be. Generally, if your glucose level is between 100 mg/dl and 250 mg/dl (5.5 mmol/L and 13.9 mmol/L) you are in the blood sugar workout happy place, so feel free to go ahead and get moving. But, if it is below 100 (5.5) you should eat a snack, like a granola bar or a cup of yogurt, to get your blood sugar level up to where it should be before you begin your activity.2 This will allow you to have fun without worrying about the effect it is having on your blood sugar.
Conversely if it is higher than 250 (13.9) you need to first check for ketones. There are a few different ways to do this, but in this case, testing your urine with ketone strips you can purchase from your pharmacy is probably the cheapest and easiest.3 If you find that ketones are present in your urine, you should contact your doctor to ask their advice before engaging in any additional activities like exercise.
In the past, recommendations for managing your numbers while exercising didn't differentiate between different types of physical activity.4 However, recent research has shown that different types of activity can have distinct effects on your blood sugar.5,6
- Aerobic or cardio exercise, such as walking, cycling or swimming, tends to lower blood sugar. You may need to have a snack, cut back on insulin or both before you begin. If necessary, opt for a snack that's high in fiber or protein so it doesn't spike your blood sugar levels. Of course, you may need additional carbohydrates if you're endurance training, but right now, we're just talking about keeping your blood sugar in line during regular workouts.
- Strength training, such as lifting weights, can increase blood sugar or provide greater stability in your numbers. Eating a snack beforehand may actually send your numbers too high.
- Interval training, in which you switch between brief periods of intense cardio and moderate recovery exercises, may lead to less variation in blood glucose numbers. As a result, reducing insulin too much could lead to high blood sugar.
These are generalizations—there are many variables, including the order in which you go from one type of exercise to the next, how fit you are, your starting glucose level, the duration and intensity of exercise, and more. The answer? Monitor your blood sugar closely before, during and after exercise.5 By tracking your numbers, snacks, insulin and your body's response to activity, you'll learn know how different exercises affect you. That way, you can adjust as needed.
How to manage blood glucose while working out
If your blood sugar is stable and in range and you are planning to be active for two hours or less, you should not need to check your blood sugar during your workout. Just remember, because exercise causes rapid fluctuations in blood sugar, that every hour after the second hour of exercise you need to check your glucose levels.4
If you happen to experience low blood sugar (below 70 (3.9)) during a workout you should treat it by following the 15-15 rule.1 Basically, what you want to do is eat 15 grams of carbohydrates, wait 15 minutes, then check your sugar again. If your blood sugar level is not back up to 100 (5.5) or more, eat 15 more grams and repeat. Some things that contain about 15 grams of carbohydrates are5
- 1/2 cup of fruit juice or regular (non-diet) soda
- 1 tablespoon of sugar or honey
- Jellybeans or hard candies—see the package to determine how many
- Premeasured glucose tabs or gel
If you are doing an extended exercise like running a 5k, make sure to bring some glucose tablets in case your blood sugar drops. It is also a smart idea to wear a medical alert tag if you are running a race so staff will know how to help you if problems do arise.
Diabetes and exercise tips and tricks
- It can be hard to feel lows during exercise because the symptoms are hard to feel when you’re exercising. Check your blood sugar often and stay mindful about it until you get the routine figured out – especially if it’s a new exercise for you.
- 120-180 mg/dL (6.6-10 mmol/L) is a great blood sugar target to start your exercise session.
- Keep fast-acting glucose nearby and readily available to treat low blood sugars. For more extended duration activities, you may need to consume carbohydrates during your exercise to prevent lows.
- If you use an insulin pump, consider reducing your basal rate or even disconnecting your pump for a while. Generally, you can program basal rate reductions for 4-5 hours or longer.
- Start your basal rate reductions on a pump 60-90 minutes ahead of time. You need at least that long before you’ll see any change in your blood sugar.
- Rapid drops in blood sugar during exercise often come from too much active insulin on board. Be extra careful of this if you’re starting a workout with lots of insulin on board, and plan if you know you’ll be working out soon after taking any insulin.
- For pre-breakfast exercise, average basal rate reductions are 20-50%, depending on insulin type, exercise intensity, and current fitness level.
- For endurance sports lasting more than 1-2 hours, you may only need 20-75% of the usual amount of insulin for the meal before exercise.
- Full-time (all day) activities often require lowering meal and basal insulin for the next 24 hours after the exercise. For medium intensity activities, the basal requirement is reduced by 30-50% and for very high and long intensity activities by 50-75%.
- For type 1 diabetes, eating at least 90 minutes after your workout may reduce the risk of overnight lows. Especially in the afternoons or evenings, you can reduce your insulin intake by up to 50% or eat small extra fat and protein snacks before you go to sleep without insulin. Everyone, however, is unique and you’ll need to experiment a little bit to find the right balance for you.
- After the strength training, which can initially lead to higher blood sugars, insulin requirements may fall over the following 6 hours as the liver replenishes its reserves. You can compensate for this with less insulin at the next meal or additional snacks. For pump users, a basal rate reduction of about 30% might also be an excellent place to start.
- Take special care with alcohol after exercise – this will prevent your liver from releasing sugar. In this case, increased insulin sensitivity and reduced sugar release overlap! Watch out for low blood sugars! Keep your wits about you and your glucose tabs ready!
What to do after a workout
It's important to keep in mind that, while it's more common in people who use insulin, you can be at risk of going low for 24 hours after exercising.5,6 If you work out during the afternoon, this could lead to an overnight low. If your blood sugar is elevated after exercise, a correction dose of insulin may be appropriate, but be careful not to overcorrect.5
Research also suggests that a meal or bedtime snack that's low on the glycemic index, meaning it includes protein, fat or fiber to slow the carbohydrates' absorption into your bloodstream, may reduce the risk of an overnight low.5
Diabetic fitness plans
Whether you work out at the gym or at home, you can boost activity in your diabetes management. Check out the sample exercises below and be sure to discuss any changes with your healthcare team before you begin.
15-minute diabetes exercise routine
- Stretching gets your body ready for exercise. Try toe-touches or lunges for 1 minute.
- Arm circles build strength. Hold your arms straight out to your sides, then make 25 small and 25 large circles. Try to keep your shoulders down.
- Calf raises are an easy strength-building and toning exercise for everything from the waist down. Start with 20 for each workout.
- Run in place to get your heart pumping for 10 minutes. Add jumping jacks for a fun alternative.
BY CHRISTEL OERUM (DIABETES STRONG)
I absolutely love resistance training! I love how empowered it makes me feel and how it helps me manage my diabetes.
Resistance training simply means that you put your muscles to work, building strength by using your bodyweight, resistance bands or weights. The beauty of all of these options is that resistance training doesn’t have to happen in a gym and you don’t need a lot of expensive equipment.
I find it so empowering because I love seeing myself get physically stronger week by week, and it is immensely satisfying to be able to do one more squat than last week or lift a heavier dumbbell. Progress is always motivating!
If you need more convincing that resistance training is a great thing, it can also improve your metabolism, burn stored fat and glucose, and improve your insulin sensitivity (how well your body uses insulin) regardless of if you inject insulin or produce it yourself10.
What to know about resistance training if you live with diabetes
If you are used to walking or other types of aerobic exercise (activities where your heart rate stays elevated), you are probably used to exercise making your blood sugar drop. Resistance training is a little different, and you might find that your blood sugar stays the same or even increases temporarily. So, what gives?!?
When you do resistance training, you put your muscles under tension for a short amount of time before taking a break and then repeating (e.g. do 10 squats, rest for 30 seconds, and then 10 more squats). That means that your heart rate will fluctuate throughout your workout.
This type of exercise and heart rate response (called anaerobic exercise) typically has little impact on blood sugar or can even make it go up while you exercise11. The good thing is that blood sugar usually comes down after exercise and you might see a significantly improved insulin sensitivity for up to 24 hours after you have worked out.
To manage my blood sugars during resistance training, I often have to adjust my insulin before and after the workout to reduce the risk of my blood sugars going high or low.
Of course, we are all different, so you might find that you don’t need to make any changes or that you need to make significant changes to your medication. A good place to start is to discuss strategies with your medical team and take it from there.
If you do not inject insulin, you obviously cannot adjust it. However, please know that because resistance training will improve your insulin sensitivity, it is tremendously useful for people living with any type of diabetes, even if you see a small blood sugar increase during your workout.10
Fueling my workouts and using the right levers to limit high or low blood sugars
I hope that you find resistance training to be as enjoyable as I do. Some people see improved strength in as little as two weeks so it is definitely an activity that gives quick returns.
But success at resistance training comes down to more than just using your muscles, you also need your nutrition to support your goals.
This doesn’t have to be a boring meal. It is a great opportunity to make yummy snacks like protein pancakes, heat up a chicken casserole, enjoy leftovers from last night’s dinner or grab your favorite yogurt and an apple.
I include protein before and after a resistance training workout because muscle fibers are broken down during the workout, and muscles need protein to heal and grow back stronger12. The carbohydrates give you the energy to complete your workout, and I’ve found that it can help manage the potential blood sugar increase you may see from resistance training.
It is generally recommended that you measure your blood sugar before and sometime during exercise, especially if you treat your diabetes with insulin. That is the only way you will truly understand how your body reacts to different types of exercise and how you will learn to adjust your diabetes management.
My favorite resistance training exercises
You might be reading this post thinking, “This is all great, Christel, but what exercises should I be doing?”
This is an excellent question, and although the exact exercises will depend on what equipment (if any) you have available, there are some exercises that I highly recommend in any resistance training workout.
I always recommend what I call the “large” exercises, where you use many different muscles groups to do the exercise. By working several muscle groups at once, you maximize your time spent.
My top 3 “large” exercises are:
- Squat variations – Squat down until your knees are at a 90-degree angle (or less if you are very flexible) and stand up again. You can also simply sit down on a low chair and stand up again if freestanding squats are too difficult.
- Push variations – Push-ups on the floor or against a wall (easier)
- Pull variations – Any exercise where you work your back muscles by pulling something towards you.
Don’t worry if you don’t know how to perform these exercises. I have a whole library of resistance training workouts for both at home and in the gym on Diabetes Strong where I demonstrate multiple variations of each exercise.
Anytime you start something new, you should always go slowly. You need to push yourself a little to get stronger, but going from 0% to 100% overnight will only end in injuries. Do your research and learn how to perform the exercises, or have a trainer at your gym walk you through them. Most gyms will give you an intro workout with a trainer for free or at a large discount.
Resistance training is no longer only for big grunting bodybuilders. People of all ages are falling in love with resistance training and the benefits it brings - especially for us living with diabetes.
How to lose weight with diabetes
People always seem to be talking about losing weight. Yet, as a country, we just keep getting bigger. So how can we align what we want to do with what we actually do? Here are a few tips that might help.
- Create a fair timeline. You didn't put weight on all at once, so don't expect it to come off in an instant. Doctors suggest that a safe rate of weight loss is about 1/2 to 2 pounds a week.13 Any more than that isn't healthy—or sustainable.
- Don't go it alone.
If you use insulin to maintain safe blood sugar levels, you'll want to talk to your doctor about how to alter your diet and activity to lose weight safely. Manipulating your insulin won't give you the long-term results you're looking for.14
- Set achievable goals.
Health experts consider a 5- or 7-percent weight reduction goal over 6 months to be a realistic starting point.13 If you need to lose more than that, break your ultimate goal into several short-term goals and tackle them one at a time. Think about how you'll get there—by keeping foods that encourage you to binge out of the house? Weighing portions? Walking to work? Put your plan in writing and keep it where you can see it.
- Stay in charge.
If you find yourself in a restaurant or situation you didn't expect, remember—even the most notoriously unhealthy fast-food outlets have something reasonably healthful on the menu. And even if they hand you something super-sized, you don't have to finish it all.
- Be forgiving.
Why is it so easy to forgive other people, but not ourselves? If you slip a little, skip the guilt trip. Let yourself off the hook and get right back on track toward reaching your goals.
- Keep your chin up.
Come at weight management with a positive frame of mind—thinking about how good you'll feel and how your efforts are paying off. Start believing you can do it, and you're more likely to be right.
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Colberg, Sheri. “What Is the Best Time to Exercise with Diabetes?” Diabetes In Control. A Free Weekly Diabetes Newsletter for Medical Professionals..., DiabetesInControl.com, 6 Feb. 2015, www.diabetesincontrol.com/what-is-the-best-time-to-exercise-with-diabetes/. Accessed June 5, 2019.
Colberg, Sheri R. “Key Points from the Updated Guidelines on Exercise and Diabetes.” Frontiers in Endocrinology, NCBI, 20 Feb. 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5317029/. Accessed June 5, 2019.
“DKA (Ketoacidosis) & Ketones.” American Diabetes Association, American Diabetes Association, 18 Mar. 2015, www.diabetes.org/living-with-diabetes/complications/ketoacidosis-dka.html. Accessed June 5, 2019.
Riddell, Michael, and Bruce A. Perkins. “Exercise and Glucose Metabolism in Persons with Diabetes Mellitus: Perspectives on the Role for Continuous Glucose Monitoring.” NCBI, US National Library of Medicine National Institutes of Health, July 2009, www.ncbi.nlm.nih.gov/pmc/articles/PMC2769951/. Accessed June 5, 2019.
Polonsky, WH. Diabetes Burnout: What to Do When You Can’t Take It Anymore. Alexandria, VA: American Diabetes Association; 1999.
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3Maguire, Emily. “When and How Should You Measure Ketosis?” Emily Maguire: Low Carb Genesis, 5 Sept. 2017, lowcarbgenesis.com/blog/when-and-how-should-you-measure-ketosis/. Accessed October 23, 2018
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5Riddell MC, Gallen IW, Smart CE, Taplin CE, Adolfsson P, et al. Exercise management in type 1 diabetes: a consensus statement. Lancet Diabetes Endocrinol. 2017;5:377-90. Available at: https://www.thelancet.com/pdfs/journals/landia/PIIS2213-8587(17)30014-1.pdf. Accessed June 7, 2018.
6Colbert SR, Sigal RJ, Yardley JE, Riddell MC, Dunstan DW, et al. Physical activity/exercise and diabetes: a position statement of the American Diabetes Association. Diabetes Care. 2016;39:2065–2079. Available at: http://care.diabetesjournals.org/content/diacare/39/11/2065.full.pdf. Accessed June 7, 2018.
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10Eves, Neil D., and Ronald C. Plotnikoff. “RESISTANCE TRAINING FOR THE MANAGEMENT OF TYPE 2 DIABETES.” American Diabetes Association, American Diabetes Association, 27 Apr. 2006, care.diabetesjournals.org/content/29/8/1933. Accessed April 4, 2019.
11Lukács, Andrea, and László Barkai. “Effect of Aerobic and Anaerobic Exercises on Glycemic Control in Type 1 Diabetic Youths.” US National Library of Medicine National Institutes of Health, NCBI, 15 Apr. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4398909/. Accessed April 4, 2019.
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