Insulin dose adjustment for physical exercise
insulin dose pages from DAFNE
Principles of exercise and activity
Exercise helps our general health. You can exercise as often as you like,
and participate in a wide variety of sports and activities. For some dangerous
activities, e.g. diving, you may need specialist advice.
A person without diabetic does not have hypos during exercise. Their body
naturally reduces the amount of insulin releaaed.Also, increased activity
of any sort will speed up the rate at which you use glucose, as it is burned
up for energy. Therefore, it is important to plan ahead to prevent unnecessary
hypos during or after your activity.
Exercise that is very much more than you are used to (either more vigorous
or more prolonged) may keep your blood glucose low for up to 18 hours afterwards.
This is due to the body replacing the glucose it had stored in its muscle,
which was used for the exercise. This does not just apply to sport. It also
applies at other times of increased physical activity e.g. spring cleaning,
moving house, shopping, sex, or gardening.
Things to consider when planning physical activity or exercise:
- Always carry rapid acting CPs .
- Monitor blood glucose before and after any physical exercise or activity
- Give hypo treatment if blood glucose drops below 3.5mmol/l before exercise.
- Consider the timing of when any insulin has been given.
- a really excellent site, read carefully
Hypos can be prevented either by reducing your insulin or increasing carbohydrate
intake during and/or after the exercise.
Options for activity and exercise
||aim to lose weight
||focus on reducing insulin
|weight not an issue
||focus on increasing carbohydrate or reducing insulin
Unplanned activity or exercise
||Only option is to increase carbohydrate
It is not possible to give exact dose reductions. You need to determine
the effect of exercise on your blood glucose by self-monitoring and adjusting
your insulin dose.
If your diabetes is poorly controlled or your blood glucose is raised (e.g.
over 13mmol/l) prior to exercise, the exercise probably will not lower your
blood glucose level significantly. It is likely that your blood glucose level
will rise....this is because you probably do not have enough insulin circulating
in your body. Consider injecting an extra dose of quick-acting insulin to
reduce the level before your exercise, and always check for ketones.
If ketones are present in your urine you need to avoid exercise until your
blood level is below 13mol/l. Follow the advice given for positive ketone
|If the activity is less than 45 minutes duration
|blood glucose level
|less than 7mmol/l
||take 2-3 CPs depending on how strenuous the activity
||take 1-2 CPs depending on how strenuous the activity
- no extra CPs needed.
- Consider when you last ate?
- Is your insulin running out?
- If the activity is more than 30minutes, retest (you may need extra
CPs as above)
|more than 13 mmol/l
||Test for ketones. If ketones positive, postpone
exercise and consider extra quick-acting insulin
Type of exercise
|type of exercise
||walk to shop - 20 minutes
||do nothing, carry rapid action carbohydrate
||bike ride -- 35-45 minutes
||additional 1-2 CPs
|Prolonged/intense--upto 4 hours
||aerobic class 1 hour cycling 4 hours
||30-50% reduction in insulin dose prior to exercise Extra CPs may be needed.
longer than 4 hours
|a day hiking
- reduce both long acting and quick acting insulin
before exercise by 50%
- Reduce any insulin during exercise by 50%
- Reduce dose immediately after by30-50%
- Increase carbohydrate snacks may be be necessary
There is an increase risk of hypos
for some time after exercise whilst the body is replacing its used
energy stores. The background dose in the evening and possibly the
following morning after prolonged exercise may also need to be reduced
For Lantus users you may need to focus on quick-acting insulin and/or
eating more CPs, rather than reducing the Lantus. A twice day background
insulin, such as Levemir, may be better. Lantus lasts nearly 24 hours
or even longer, whereas Levimir is shorter acting, and so Levemir
is easier to adjust for prolonged exercise.
Diabetic Athlete', Sheri Colberg gives expert advice, and is
worth buying or reading (you can usually ask your
local library to get a copy).
DK recommends insulin pumps if you take a lot of exercise, particularly if you take a lot more on some days than others. See for expert advice.
Advice from Good Hope
This is an extract from Dr Sharon Jones, Nov 2006, talk for professionals, here
5mb powerpoint : Exercise in diabetes. aerobic, anaerobic exercise.
Improve/maintain health. Exercise helps even if no weight lost. Hypos and
avoiding them, pregnancy, neuropathy. The athlete, pre-& post exercise.
Fluids, monitor glucose level. Slow and steady, weight loss programs, housebound
programs, case examples.
Here are some of the case examples.
- uses novarapid before meals and detemir twice daily
- runs after after breakfast
- sips a sugary drink during the run
- reduces breakfast novarapid 25%, with lighter breakfast
- Usual insulin with increase CHO for lunch
- If exercises before breakfast- Less sugary drink during the run
- just as needed - normal insulin with breakfast after run
- Football team, both midfield player and goalie have
type 1 and are treated with basal bolus insulin
- Pre match meal-- Midfielder reduces bolus insulin by 50-75% --
Goalie by 25%
- Pretraining meal-- Both midfielder and goalie reduce insulin
by 40% -- And basal by 10%
- Rower...training - reduce insulin, more so if cold,
hot or windy
- Racing - check glucose pre-race and give extra units
if raised anticipating further rise from anaerobic metabolism
- Tennis - greater reduction in dose if playing singles
- Golf - usual reduction of around 20% with snacks each
hour (half banana) but even less insulin or more snacks if caddie fails
to turn up