Exercise is very important in managing type 2 diabetes. But how much exercise do you need and what is the best way to get it?
Exercise helps control you blood glucose level by:
- improving your body’s use of insulin,
- reducing your weight (which in turn further improves your insulin sensitivity),
- reducing stress (which is one cause of insulin insensitivity), and
- lowering your blood pressure and cholesterol levels (both of which are linked with diabetes in the metabolic syndrome).
In a healthy person, insulin is released from the pancreas when the amount of glucose in the blood increases, such as after eating. Insulin opens the receptors in your muscle cells so the excess glucose can get into the cells. Thus, after it peaks, your blood glucose level falls.
The effects of exercise
When exercising, however, your muscle cells need extra energy or fuel (in the form of glucose). For short bursts of exercise, such as a quick sprint for a bus, your liver releases stores of glucose which your bloodstream transports to your muscles.
With continuous moderate exercising, your muscles take in glucose at up to 20 times their normal rate. This helps lower blood sugar levels as the glucose disappears into the cells.
At the same time, as the glucose in your bloodstream diminishes, your insulin levels drop (provided you are not taking insulin), reducing the flow of sugar into your muscle cells. Thus the risk of hypoglycaemia (a fall in blood glucose to dangerously low levels) is minimized.
On the other hand, intense exercise (exercise that causes you to break out in a sweat and raises your heartbeat) can have the opposite effect. You may find that your blood glucose levels are temporarily increased immediately after you stop exercising.
This is because your body recognizes intense exercise as a stress and releases stress hormones that tell your body to increase the blood sugar available to fuel your muscles. This in turn causes your blood sugar to shoot up to a peak and then drop.
After intense or endurance type exercise, your glucose level can remain low for 24 to 48 hours.
This is fine, as long as it does not drop much below 3.9mmol/L (70mg/dl), which is the danger point for hypoglycaemia.
Eating a snack before you begin exercising may help counteract this. And, of course, you should check your blood sugar before, during, and after you exercise.
Types of exercise
There are plenty of exercises that are especially useful for diabetics and which you can do at home provided you have some elastic exercise bands and cross-trainer. There’s no need to go to a gym.
Resistance training is a type of exercise that uses resistance to induce your muscles to contract. This builds the strength, endurance and size of your muscles.
You can do this sort of exercise at home using elastic exercise bands wrapped around a stair-post or something similar. This form of strength training builds your muscle mass so you use glucose more efficiently.
It also increases your metabolism, improves your cardiovascular health, lowers your blood pressure and reduces your abdominal fat.
Interval training involves alternating bouts of high-intensity activity with less intense work. You can, for example, pedal quickly on a cross-trainer for 30 seconds and then go at a slower speed for 90 seconds.
Alternating the speed and intensity of the workout challenges you muscles. This helps burn more calories, boosts your fitness and improves your insulin sensitivity.
Exercise for diabetics
A sedentary existence with little or no exercise implies that your muscles are not burning glucose or calories. If you start exercising, your muscles will begin to use up your glucose and calories.
For diabetics, in my view, plenty of moderate exercise is best.Undertaking some form of exercise is easy.
Many of the chores you do around the house, such as cleaning or mowing the lawn, involve moderate exercise and are very beneficial.
Walking is an excellent form of moderate exercise, provided you do it for at least 30 minutes a day. Here are a few simple tricks to get your walking time in.
If you live in an apartment, forgo the lift for the stairs once a day, for at least two flights of stairs. Walk to the grocery store instead of driving, or park your car as far away as possible from the entrance to your local supermarket.
Obviously more intensive exercise will improve your blood glucose levels even more than moderate exercising. However you need to keep in mind that your blood glucose levels can keep dropping for up to 48 hours after exercising.
Starting an exercise programme
If you have not had any exercise for years, you should talk to your doctor before you start.
If you have heart problems, you may need a stress test as a precaution. If you have hypertension, you need to make sure that your blood pressure is stable.
If you have problems with your retina, your doctor should be able to tell you what exercises to avoid in order not to impose pressure on your retina.
If you have problems with your bones, such as back problems or knee pain, an exercise physiologist can show you appropriate exercises such as how to use a recumbent stationary bike.
You should check your blood glucose before and after your exercise. Not only will you be keeping tabs on your blood sugar, doing so can be a great motivator. When you see that your blood glucose is going in the right direction, you’ll probably do more exercise.
You should also keep fast-acting snacks on hand in case your blood sugar drops too low while you are exercising.
If you go out walking or jogging, or go to a gym, you should wear a diabetes ID bracelet so that if you need emergency help you are identified as a diabetic. The ID should show whether you take insulin and have an emergency contact number.
You should, of course, wear shoes that are appropriate for the type of exercise you are undertaking. It’s all too easy to forget that diabetes can have a devastating effect on your feet.
