Diabetes and exercise


Let’s face it - exercising regularly makes you look and feel better. This energetic image you project is due to the extensive benefits provided by regular physical activity. These include improved stamina, lung capacity, heart function, joint flexibility and bone strength, blood circulation, mental alertness, psychological well being and of course more effective weight control.

Therefore, it should come as no surprise that inactivity can be a major health risk and can significantly increase your risk of suffering from chronic diseases of lifestyle, which are diseases directly influenced by choices we make i.e. what we eat, whether we smoke, how we handle stress and whether we are active or not.

Type 2 diabetes (a chronic disease of lifestyle), is highly affected by factors such as your weight and activity levels, two lifestyle choices over which we have control. 

1. Does exercise really help Diabetes?

The answer is a very definite YES. 

Exercise can help to reduce your insulin requirements in two principle ways:

  • Exercise increases the body’s sensitivity to insulin.
  • Exercise enhances the more efficient use of blood glucose, thereby lowering it. It also possibly reduces the amount of medication needed to treat diabetes. With type 2 diabetes, it may even eliminate the need for medication, when accompanied by a healthy eating plan. 
  • Exercise has the ability to reduce your cholesterol levels and high blood pressure, and in the long term can reduce the development of heart disease or stroke. This is important because diabetic individuals have a higher risk of developing heart and circulatory problems. 
  • Exercise, when accompanied with a well balanced diet, can help reduce your body fat (especially abdominal fat), since it burns extra calories. This is of particular importance to the overweight diabetic.
  • Exercise can improve your circulation, especially in the arms and legs, where people with diabetes can have problems.
  • Exercise helps to reduce stress levels, which can raise your glucose level.
  • Exercise can improve the quality of life of diabetics.

What are the best kinds of exercise?

As a guideline the most effective exercise for people with or without diabetes is aerobic or cardiovascular exercise, which increases the heart rate, may cause a sweat and works the heart and circulatory system. It includes:

  • Walking
  • Jogging or running
  • Cycling
  • Aerobics
  • Swimming, any racquet sports and others 

Calling exercise "an underutilised therapy", the American College of Sports Medicine (ACSM) explains in a position statement that very few diabetic patients use exercise as a way to help control their symptoms and lower their risk of developing serious complications, despite the fact that it has proven benefits.

"Physical activity, including appropriate endurance and resistance training, is a major therapeutic modality for type 2 diabetes," the committee concludes. They recommend that diabetics exercise three to five times a week and burn a total of about 1 000 calories (4184 kilojoules). Patients can begin with 10-15 minutes of exercise and work up to 30 minutes per session (Medicine and Science in Sports and Medicine 2000).

3. Exercise/sports to avoid?

Type 1 diabetics, particularly, should avoid sports where a hypoglycaemic event (low blood sugar) could be extremely dangerous, and these include:

  • Diving (high board diving or bungee jumping)
  • Climbing
  • Single-handed sailing
  • Motor racing
  • Special points: For those diabetics who have:
    • Proliferative retinopathy (a non-inflammatory disease of the retina), strenuous exercise or excessive straining is NOT RECOMMENDED due to the increased risk of possible haemorrhage (bleeding) in the vitreous space in the eye.
    • Peripheral neuropathy increases the danger of injury to the feet. If the condition is mild, suitable footwear can provide sufficient protection, but if it is more severe, weight-bearing exercise should rather be avoided. Rather select swimming, cycling or rowing if you have a loss of protective sensation. 

Getting started – some general advice and recommendations

Medical Check and Exercise Prescription (do before starting to exercise)

  • Have a complete physical evaluation.
  • Have an exercise stress test because of the increased risk of heart disease.
  • Consider diabetic complications (hypoglycemia, dehydration etc), before selecting your type of exercise.
  • Estimate energy expenditure so as to help balance energy intake, energy output and insulin requirements.
  • Your doctor or an exercise physiologist or biokineticist can help you create an individualised programme to suit your particular needs.

Exercise, eating and your glucose levels

  • Do not exercise if your blood glucose exceeds 250mg/100ml and if urinary ketones test positively.
  • Eat within two hours of exercising.
  • Eat or drink some extra carbohydrates if glucose levels are below 100mg/100ml.
  • Always have quick-acting high carbohydrate on hand such as hard glucose sweets. 
  • Drink enough fluids before, during and after exercise.

Monitoring your blood glucose before and after exercise

  • Learn to control blood glucose systematically by keeping track of each exercise session’s duration and intensity as well as your blood glucose levels.
  • Learn to identify physical responses to hypoglycaemia immediately.
  • Insulin injections
  • Avoid insulin injections one hour before exercising.
  • Reduce the dose of insulin when exercising.
  • Use non-exercising body sites for injection. 

General precautions

  • Exercise regularly, ideally at the same time each day.
  • Be consistent with exercise and also with meal times and insulin injections. 
  • Have a high carbohydrate snack about 15 minutes before exercising. 
  • Avoid heavy exercise during peak insulin action. 
  • Protect your feet by wearing good-fitting shoes and cotton socks. 
  • Avoid activities that cause blisters.
  • Carry medical identification and try to exercise with someone else who is informed that you are diabetic
  • If you feel an insulin reaction coming on while exercising, STOP IMMEDIATELY and have some glucose. 

5. Type 2 diabetes – a few extra points

Almost 9 of 10 people with type 2 diabetes are overweight! Therefore weight loss is often the first line of treatment recommended by doctors. This again brings home the importance of a low fat (especially saturated fat), balanced diet and regular exercise as part of the solution to the disease.

Most often, type 2 diabetics are past 40, so as you get older, you need to be especially careful.

6. Some important tips to help you stick with your exercise programme

  • Set a schedule, diarise it and STICK to it! Make the commitment to exercise just as you would any other important appointment. Remember, habits are developed through practice. 
  • Get a training partner. On days when motivation levels are flagging, we are easily tempted to skip our workout. You and your partner’s collective resolve can also help to keep you on track! Why not set joint goals to keep you even more motivated. A training partner who is aware of your diabetes can mean safer exercise sessions. 
  • Cross-train to avoid boredom. Don’t do the same exercise every session; rather have some variety (i.e. cross-train). For example, you might ride a bicycle one day, walk the next, and swim another day. It not only gives you variety in your routine but also reduces the risk of injury by avoiding straining the same muscles due to overuse. 
  • Set goals. Setting specific goals for yourself and then evaluating how you are doing with your goals is a great way to keep on track. Remember to write them down so that they are more tangible. But be realistic, unrealistic goals can work against you. 
  • Reward yourself. One good way to keep your motivation high, is to reward yourself when you accomplish a goal; for example with a new item of training gear, a book, a massage – anything healthy that will keep you motivated.
  • Find a pleasant setting for exercise since this will also help to keep you motivated. Try a park near work where you can walk, or find a clean, attractive fitness centre. 
  • If your schedule is tight, make exercise time productive i.e. prop your newspaper up on your stationary bike, or park your treadmill in front of the TV so you can watch the news or be with your family. 

7. Suggestions for an exercise programme for beginners

Before beginning any sort of physical activity at all, please carefully read and work through all of the advice in point 4.


Before even thinking of more formal exercise, try to activate your day as much as possible by walking the dog, taking the stairs, walking to fetch the newspaper rather than driving, mowing the lawn rather than getting in a gardening service etc.


Exercise for people with Type 1 diabetes
SPECIAL NOTE: If you are not needing to lose weight, increase your energy intake to match your increased energy expenditure. This is particularly important during strenuous activity when you need to replace the energy you have burned. Always have some fast-acting carbohydrate on hand too.

Exercise for people with Type 2 diabetes
If you are overweight, you might need to start off with a gentle walking programme to get you accustomed to regular activities. Remember that you are wanting to lose weight, so as to improve your condition. Consult with a registered dietician to ensure that your eating plan allows you to exercise safely, but also promotes weight loss. 

An exercise session

A typical session will be comprised of:
a) A warm-up (5 minutes), prepares the body for more strenuous activity and helps to prevent injuries (walking, swinging arms etc.)
b) The aerobic phase is the period of more intense exercise (walking, jogging, cycling etc). Heart rate and breathing rate increase.
c) Stretching after your session keeps you flexible and decreases your chances of injury. 
d) The cool down (5 minutes) gradually returns your body to its normal state. This prevents pooling of blood in the arms and legs, which could otherwise cause fainting.

Aim to build up the “aerobic session” from 15 minutes to about 30 or 40 minutes to maximize the health benefits. 

Lifting weights?

Nearly all people who have diabetes can incorporate upper-body strength training with light weights and high repetitions. More strenuous strength training may be acceptable for young people who have diabetes, but it is not recommended for older patients or those who have long-standing diabetes. 

Written by Kathleen Mc Quaide-Little of the Sport Science Institute of South Africa

Check out Health24's fitness programmes (from beginners to advanced) to get started.

- (Health24, updated November 2012)

(Pic of exercise woman stretching from Shutterstock)

Read more:

20 proven exercise benefits
Basic diabetic menu for one week
10 exercise motivators

Any questions? Ask our Diabetes Expert

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