Diabetes and Exercise: Control Your Blood Glucose Levels with Physical Activity
Experts from Singapore General Hospital (SGH), explains how people with diabetes can benefit from regular exercise.
Maintaining regular weekly exercise and physical activity is a key part of living well with diabetes.
Our expert from Singapore General Hospital (SGH), a member of the SingHealth group, Associate Professor Cindy Ng Li Whye from the Department of Physiotherapy weighs in - Exercise has been documented in many studies to improve the body’s ability to use the glucose in the blood and decrease insulin resistance. If you have diabetes, aerobic training such as walking, jogging and cycling, will help to control your condition to an extent similar to that of some oral diabetic medications. Weight training may be beneficial as it preserves muscle tissue that is otherwise slowly lost with age.
Along with a proper meal planning approach and taking your diabetes medications as prescribed, a diabetic can still LIVE WELL!
How exercise benefits people for diabetes
“Physical activity increases your body cells’ sensitivity to insulin, making insulin work better for you in moving glucose from your bloodstream into the cells to be used as energy,” says Ms Kala Adaikan, Senior Principal Dietitian from the
Department of Dietetics at SGH.
Your body cells can also remove glucose from your blood using a mechanism totally separate from insulin during exercise.
Exercise has the potential to consistently lower your blood glucose levels and eventually lower HbA1c. This may result in you requiring fewer diabetes medications or less insulin.
Exercise and risk of hypoglycaemia (low blood glucose)
If you have type 1 diabetes or type 2 diabetes and are on insulin therapy, you are at risk of early (during exercise) and late onset (hours after or overnight)
hypoglycaemia after exercise.
How your blood glucose levels behave will also depend on the following factors:
Type of exercise (aerobic or anaerobic)
Duration of exercise
Intensity of exercise
Depending on these factors and your pre-exercise blood glucose levels, you may be required to take additional carbohydrates or reduce insulin, or do both.
Recommended Amount of exercise
If you have type 2 diabetes, at least 150 minutes of accumulated moderate intensity aerobic physical activity per week as well as resistance strength training is recommended.
To achieve 150 minutes of physical activity in a week, try to do 30 minutes of exercise 5 times a week.
In addition, physical activity paired with a well thought-out meal planning approach and nutrition intervention for weight loss has been shown to help people achieve:
- Weight control
- Improved glycaemia
- Improved blood pressure
- Improved lipid profile
Before embarking on an exercise regimen, it is essential that you receive prior education on exercise management strategies.
If you want to be active, or you are experiencing hypoglycaemia with activity, you should seek advice from your diabetes care team.
Useful pointers on exercise for people with diabetes
1. You should measure your glucose level before exercising.
|MMOL/L||Advice / What To Do|
|5.6 - 13.9(100 - 250 mg/L)||It is safe to embark on exercise|
|< 5.6 (<100 mg/L)||If less than 5.6 mmol/L, take a snack such as an apple or 1 small cup of hot chocolate|
If you are on insulin, you should avoid exercising during the peak insulin action. If exercise cannot be avoided, you should consider reducing your insulin dose by 2 to 4 units.
2. Always have a snack on hand in case of hypoglycaemia or low blood sugar.
A good snack could be one slice of bread or a small cup of plain Milo, or glucose tablets.
3. Always have sufficient fluids before, after and during exercise to prevent dehydration.
4. Choose an injection site less likely to be affected by the working muscles.
For example, if you run, do not inject the insulin into the legs as that may result in greater absorption of the insulin and increase the risk of hypoglycaemia during exercise.
Stop exercising if you experience the following symptoms and quickly check your blood sugar level, heart rate and blood pressure:
- Light headedness or dizziness
- Chest tightness / discomfort / pain (seek immediate medical attention)
- Severe shortness of breath
What is the best exercise regime for diabetes?
Walking is often an effective form of exercise. It has been shown to prevent or delay the onset of diabetes in those with impaired glucose tolerance. As such, an exercise as simple as walking is important to reduce the risk of developing diabetes.
How much should you walk and how fast should you walk? First, let’s introduce the scale called “Rate of Perceived Exertion” or RPE.
|Rate of Perceived Exertion (RPE) Scale|
|0.5||Very, very light (just noticeable)|
|9||Very, very hard|
On this scale, a slow walk would be perceived as 0 to 2. Brisk walking would reach 4 to 6. At this level, you may still be able to talk in full sentences but feel a little short of breath.
A very intense activity such as advanced step aerobics may be considered an 8. At this level, it becomes difficult to speak in full sentences.
For a person with diabetes, a level of 4 to 6 is considered ideal. For example, this could mean walking a distance of 2.4 km in 20 minutes, or any other form of moderately intense activity.
Investing in a good pair of proper footwear is important, especially as those with diabetes may have altered sensation of the feet. Wearing socks made of polyester or a blend of cotton and polyester may be useful to prevent blisters.
Is weight training ok for people with diabetes?
If you have diabetes and are new to weight training, it is important to get proper guidance and supervision. Whether you are using resistance machines or free weights, learning the correct posture and position will go a long way towards preventing injuries.
Even with simple bicep curls, it is important to choose the right amount of weights, as well as number and speed of repetitions, in order to avoid overloading the joints, the soft tissues and muscles.
What if your diabetes is affecting your eyes?
If you have an active proliferative retinopathy, you must avoid strenuous exercise and any activity that dramatically increases blood pressure. Exercises such as walking, swimming, stationary cycling and low impact aerobics are suitable.
What if your diabetes is affecting your kidneys?
If you have diabetic nephropathy, you should avoid activities which cause the systolic blood pressure to rise to 180-200 mmHg, unless your blood pressure is carefully monitored during exercise.
What if your diabetes is affecting your nerves?
If you experience “pins and needles”, you must take extra care due to the loss of protective sensation in the feet. You may need to limit the duration of weight-bearing exercises. Otherwise you may get foot ulcers and fractures without realising it.
In addition, peripheral neuropathy can increase your risk of falls. You should avoid prolonged walking, stepping exercises and jogging. Exercises of short duration, swimming, and stationary cycling are safe. However avoid swimming if you have foot ulcers.
Monitor your feet closely for blisters both before and after exercise.
If you have been diagnosed with autonomic neuropathy, you may be insensitive to low blood glucose levels. Thus it is important that you obtain your doctor’s approval before embarking on an exercise programme. Your blood glucose level should be measured before and after exercise and your heart rate should be monitored during. You may only be able to tolerate short durations of low intensity activity with frequent rests.
As a general rule, you should always check with your doctor if you haven’t been exercising regularly. You may also want to see a physiotherapist to receive specific exercise recommendations, especially if you have other medical conditions or complications.
See previous page to
learn how alcohol affects those with diabetes.