According to the Harvard Medical School, for people who live
with diabetes, exercise is one of the foundations of good
For everyone, exercise helps control weight, lowers blood
pressure, lowers harmful LDL cholesterol and triglycerides, raises
healthy HDL cholesterol, strengthens muscles and bones, reduces
anxiety, and improves your general well-being.
There are added benefits for people with diabetes: exercise
lowers blood glucose levels and boosts your body's sensitivity to
insulin, countering insulin resistance.
Highlights of research
Many studies underscore these and other benefits from exercise.
Following are some highlights of that research:
- Exercise lowered HbA1c values by 0.7 percentage point in people
of different ethnic groups with diabetes who were taking different
medications and following a variety of diet. This improvement
occurred even if they didn't lose weight.
- All forms of exercise - aerobic, resistance, or doing both -
were equally good at lowering HbA1c values in people with
- Resistance training and aerobic exercise both helped to lower
insulin resistance in previously sedentary older adults with
abdominal obesity at risk for diabetes. Combining the two types of
exercise proved more beneficial than doing either one alone.
- People with diabetes who walked at least two hours a week were
less likely to die of heart disease than their sedentary
counterparts, and those who exercised three to four hours a week
cut their risk even more.
- Women with diabetes who spent at least four hours a week doing
moderate exercise (including walking) or vigorous exercise had a 40
per cent lower risk of developing heart disease than those who
didn't exercise. These benefits persisted even after researchers
adjusted for confounding factors, including BMI, smoking, and other
heart disease risk factors.
The best time to exercise
You will hear many different suggestions about what is the best
time to exercise.
From us here at Diabetes Queensland our advice is: The best time
to exercise is when it works for you. When you can fit it into your
day, you're more likely to do it. We suggest you find 30 minutes
each day to get active because the benefits for your body are
Resistance exercise (such as weights, yoga and Pilates) causes
the liver to release glucose so blood glucose levels (BGLs)
initially increase. They decrease many hours later as the body
"pays the liver back".
Aerobic exercise (including walking, running and cycling)
reduces BGLs. Mixed exercise (eg High Intensity Interval Training
or HIIT classes) has varying effects on BGLs, and Queensland
scientists are at the forefront of furthering research into HIIT as
an effective tool to manage type 2.
All of these exercises will help your health in the long
If using insulin, check glucose levels pre, during and post
exercise. Keep a record of the following information and review
your individual responses:
- Glucose levels - pre, during and post exercise
- Carb intake - pre, during and post exercise
- Insulin adjustments and active insulin at the start of
- Duration, type and intensity of your exercise session
- How you felt during the session
Anyone who is on sulfonylureas should also note glucose levels
and take note of how different activities affect them so they can
plan for future activity.
BGL before exercising
If you use insulin, it's important to check your blood glucose
before exercising. If the level before exercise is between
5-6.9mmol/L then have 10-15g of carb such as a piece of fruit or
200g yoghurt. If you're doing resistance exercise then you can
start straight away but if you wish to do aerobic exercise wait
until you're BGLs are more than 7mmol/L before starting.
Carrying some high glycaemic index carbohydrate as a hypo
treatment, such as jelly beans or glucose tablets, is advised for
those who use insulin or sulfonylurea family of medications.
It's also a good idea to check your blood glucose after any
particularly gruelling workout or activity. If you're taking
insulin, your risk of developing hypoglycaemia may be highest six
to 12 hours after exercising.
Experts also caution against exercising if your blood glucose is
too high (over 15mmol/L), because exercise can sometimes raise
blood glucose even higher.
Consider wearing a medical alert bracelet indicating that you
live with diabetes. People on insulin or sulfonylurea medications
are most at risk of a hypo.