We recently talked about how a healthy lifestyle is important for managing all types of diabetes, but what is it about exercise in particular that is so beneficial for people with, or at risk of developing, diabetes?
Improved blood glucose control
Sugar (in the form of glucose) is the body’s preferred fuel source. It seems intuitive that when you exercise, your body needs to “burn more fuel” to meet increased physical demands, however exercise actually helps to regulate your blood glucose in many more interesting ways. After eating and digestion, your body stores unused glucose in a compound called glycogen, ready for your muscles to use for energy the next time your activity levels increase. Insulin, a hormone produced by your pancreas, controls your blood glucose through allowing the cells in your muscles, fat, and liver to absorb glucose from the blood to use as energy or store as glycogen. If you have diabetes, your body either does not produce enough insulin, or it has become resistant to it, meaning you can have normal or high insulin levels that are ignored by the cells it is meant to communicate with.
When your muscles contract during physical activity, they send signals allowing your muscle cells to take up and use glucose without the need for insulin. This means that, regardless of your insulin levels or insulin sensitivity, exercise still reduces your blood glucose level. After exercise, your body will work to replace used-up glycogen, keeping your blood glucose regulated for at least 16 hours after exercise. Insulin resistance is also reduced after exercise, helping your cells to use glucose more effectively at rest.
Why should I care about my blood glucose control?
Your blood is not supposed to contain high amounts of glucose long term. Excess glucose (or hyperglycaemia) causes your blood vessels to constrict, increasing the amount of work your heart needs to do to keep the tissues in your body supplied with oxygen and nutrients. Long term hyperglycaemia promotes inflammation and triggers processes involved in the formulation of atherosclerosis, which are the plaques in arteries that are responsible for heart disease. These changes often impact the small blood vessels that supply nerves in your body, leading to nerve damage (neuropathy). Common sites of neuropathy include the feet and eyes, as well as autonomic nerves (the nerves responsible for things you do without thinking like digestion or controlling heart rate). Damaged nerves can lead to loss of sensation, vision, movement, or slowed healing in the limbs or tissues the nerve supplies. Your kidneys, which are responsible for filtering your blood, can also be damaged by hyperglycaemia, leading to a “leaky” filter allowing proteins to be excreted in your urine. This can lead to kidney failure requiring dialysis or transplant.
These complications are not guaranteed with a diabetes diagnosis – keeping blood glucose under control is highly effective for prevention. This is why exercise is so important!
You should also make sure your blood glucose level does not get too low (known as hypoglycaemia, or a “hypo”), particularly if you are taking insulin or other glucose-lowering medications. This can cause dizziness, a pale complexion, sweating, loss of consciousness, headaches, confusion, or seizures. Make sure you carry a source of sugar (such as jellybeans, soft drink, juice, or honey) which you can consume if you feel like you are becoming hypoglycaemic, and always pay attention to your doctors’ advice about your medication, diet, and activity levels. Check in with your GP or an Exercise Physiologist before starting a new exercise program to reduce your risk of experiencing a hypo.
Improved body composition
Exercise may not result in overall weight loss, which isn’t even necessary to improve blood glucose control, but it still has important effects on your body composition. Resistance training increases muscle mass and improves muscle function, increasing the ability of your muscles to support blood sugar control during exercise. A regular exercise routine can reduce the amount of fat your body stores around your organs (visceral fat), which has been implicated for causing inflammation and insulin resistance. Exercises involving impact or heavy resistance can also help to promote bone growth and prevent loss of bone leading to osteoporosis or fractures, which commonly occur alongside diabetes due to inactivity, medication side effects, nutritional deficiencies and/or chronic, systemic inflammation.
Diabetes doesn’t prevent you from seeing all the usual benefits of exercise either, such as cardiovascular fitness, muscular strength, and the ability to get around in the world a bit easier.
Mental and emotional health
The week of the 11th of July is National Diabetes Week for 2021, with a focus on addressing the stigma against diabetes and the mental and emotional toll this can take on people living with diabetes. While exercise alone can’t change societal stigma, it can help to build resilience, improve your mood, and manage stress, improving your overall well-being.
How should I exercise?
Before even thinking about guidelines, you should make sure to exercise in a way that you enjoy, and at a level that will allow you to stay consistent over the long term. Exercise doesn’t have to involve running marathons or spending hours in the weight room (unless you enjoy that!). Any exercise is better than none, however Exercise and Sport Science Australia (ESSA), recommend that you aim to accumulate 210 minutes of moderate activity, or 125 minutes of vigorous activity per week, with 60 of those minutes including resistance exercises. Moderate intensity means that you could talk while completing it, but wouldn’t be able to sing, while vigorous intensity activity would make it difficult to get more than a few words out.
Do you need further support?
If you need help starting an exercise program to manage your diabetes, an Exercise Physiologist can help. They will give you the tools to manage your health and become a lifelong lover of exercise (okay maybe not “love” – but certainly appreciate!).