PHYSICAL EXERCISES WITH THE INSULIN PUMP
“Will an insulin pump limit my ability to exercise?” is one of the
most common questions I get asked as a clinical diabetes manager. The MiniMed
insulin pump allows you to adjust your insulin dose for short training times
and for longer periods of time. Enlite- or Sof -sensors, which are used for
continuous glucose monitoring (CGM), show sensor glucose (SG) data so you can
see your glucose trends before, during, and after your workout. To find out how
different types of physical activity affect your body, use the LMWH to monitor
your sensor glucose levels and check your blood glucose (BG) levels with a
glucometer before, during, and after exercise.
PREVENTION OF HYPOGLYCEMIA
The risk of developing hypoglycemia associated with physical activity depends
on the type, duration and intensity of exercise, and measures to manage this
risk should be taken during and after exercise. Some people may need to prepare
an hour or two before class to ensure that their glucose levels are at a safe
level. It all depends on the characteristics of the organism. Talk to your
healthcare provider about the type of exercise you will be doing and how best
to manage your insulin regimen before making any adjustments yourself.
If you are using a MiniMed pump paradigm Veo , the Threshold Stop feature will
automatically stop insulin delivery when sensory glucose values reach a pre-set
low threshold.
If you are planning to exercise, it is best to always have 15 grams of fast
carbohydrates (eg 120 ml of orange juice or 3-4 glucose tablets) with you and
keep them in an easily accessible place. If you are exercising between meals,
check your blood glucose before you start exercising. If your BG is below your
desired level, you can adjust your basal insulin with a temp basal setting (but
follow your healthcare provider’s instructions) or have a small snack
containing 15 grams of carbs, such as crackers, an apple, or whole wheat toast.
If your glucocorticoid level is below 50 mg/ dL (2.8 mmol/L) try to get 20
grams of carbs.
TIME AND DURATION ACCOUNT FOR INSULIN ADJUSTMENT
Consider time and duration when adjusting insulin and always follow your
healthcare professional’s advice. Your need for insulin can be affected by the
time of day you exercise. For example, in the morning, glucocorticoid levels
tend to drop less during exercise due to the presence of hormones that help
maintain glucocorticoid levels at this time, so you can exercise at your
doctor’s recommended insulin settings. In the afternoon, hormone levels drop,
so you may need to temporarily lower your basal insulin supply to prevent
hypoglycemia.
Prolonged physical activity (90 minutes or more), such as moderate jogging or
swimming, can lower your blood glucose. In this case, a temporary basal insulin
adjustment may be necessary. According to the Management of Insulin Therapy
During Exercise in Patients with Type 1 Diabetes study , the recommended
starting point is to set a temporary basal rate at 50% of normal or standard
basal rate for one to two hours prior to physical activity (1). At the same
time, short-term exercise (such as sprinting or lifting heavy weights) can
increase blood glucose by causing the release of hormones, particularly
adrenaline, which releases the glucose reserve from the liver. Thus, short-term
exercise may not require basal insulin adjustments. It is important to check
with your healthcare provider before making any changes to determine which
option is best for you.
ADJUSTING BOLUS INSULIN WITH A MEAL
According to the ADA and Robert Walsh, author of Pumping Insulin , if
you eat up to 90 minutes before you start physical activity, you may need to
reduce your mealtime bolus insulin to maintain optimal blood glucose levels.
Below are a few examples of adjustments based on exercise intensity and duration
that have been effective in some patients (2,3). Remember that you need to
constantly consult with your doctor. As with insulin to carb ratios, there is
no one size fits all solution when it comes to insulin and exercise. Balance
can only be found by trial and error.
- Low intensity, less than 60 minutes: Reduce bolus by 10% – 20%
- Moderate intensity, over 60 minutes: Reduce bolus by 50%
- High intensity, less than 60 minutes: 50% bolus reduction
- High intensity exercise, over 60 minutes: Bolus reduction of 70% or more
DISCONNECTING THE PUMP
The need to disconnect your insulin pump depends on your body’s response to
physical activity and the type of activity. In some cases, the pump must be
disconnected, for example, when swimming, surfing or other types of water
exercises. There are times when close physical contact is expected and turning
off the pump can help prevent damage to the pump. If you are considering
disconnecting your pump, consider time, duration of disconnection, and exercise
intensity. This will help determine the parameters and the need to adjust
insulin. If you disconnect your pump for less than 60 minutes, you usually
don’t need to change your basal insulin, disconnect your pump for more than 60
minutes, consider reconnecting after 60 minutes and delivering 50% of your
normal basal insulin rate as a bolus. As always, you should discuss with your
healthcare provider the plan to replace insulin that you did not receive when
your pump was turned off.
CORRECTION OF HIGH BLOOD GLUCOSE
What to do if you go to a workout but your BG is high? If BG is significantly
outside the target range of 14 mmol/L) and above, a ketone body test should be
performed. Activity in hyperglycemia can be somewhat impaired, but if ketone
bodies are absent, it is generally safe to exercise. Be sure to talk to your
healthcare provider before you start exercising to determine a course of
action. Remember to drink plenty of fluids, and Robert Walsh, author of Pumping
Insulin, recommends considering administering 50% of the Bolus Wizard’s
recommended pre-workout correction(3).
USE OF BINDING TECHNIQUES DURING TRAINING
There is a wide variety of infusion sets and attachment methods available on
the market today for pump users. If you have difficulty turning off the
infusion set during exercise, place it in a place where the skin will not sweat
or stretch excessively (for example, on the arms or buttocks). Additional
dressings (such as Tegaderm or IV 3000) may be used, and tight-fitting clothing
may be worn over the infusion set to prevent it from shifting.
We look forward to your advice and comments, and do not forget to discuss any
problems with your doctor! Whatever your plans – increase physical activity, go
hiking or train for a marathon – take care of your health!