How do you handle insulin while working out?

I get up every morning, eat b-fast, and head to the gym. I usually put my pump on “suspend” while I do cardio and then turn it back on when I lift weights (post-cardio). This seems to keep my sugars high enough to work out, but not too high. Two DNEs have told me this isn’t a good idea b/c my body needs insulin mostly all the time. I don’t see the big deal b/c isn’t my bolus from b-fast working in my system while I’m working out? And, if my numbers are ok, is it big deal that my pump is on suspend for an hour?

Look at it this way (a DNE said to me) the people exercising around you haven’t turned off their pancreas’s while they’re at the gym. Why does it make any sense for you to do it?


I thought the same as you, the exercise was a substitute for the insulin. Wrong. The exercise you do now has an affect now and a few hours from now. BUT the insulin you DON"T take now has an effect about two hours from now. Check your stats and see if there’s a rise in your BGs a few hours after you’ve turned your pump off.

Whatever works works, but going without insulin could have nasty side effects. For me, it resulted in a few bouts of ketoacidosis after a work out because I had, basically, blown all the insulin out of my system by a) turning off my pump and b) running for 45 minutes. Guess when it showed up - about an hour and a half after my run.

Now I keep it on if I’m exercising for less than an hour. For longer runs, I reduce my basal to 50% of normal starting 30 to 60 minutes before and go back to normal right after. My endo has recently suggested reducing it by only 20% since I’ve had some lows during long runs. Your Mileage May Vary.

I recommend doing some research by reading “pumping insulin” by John Walsh and/or “The Diabetic Athlete” by Sheri Colberg.


Thanks, Terry. :slight_smile:

Yeah, they used to have me take off my pump for swim practice, big mistake. That was two hours though, I think you might be allright for 45 min as long as you don’t do any anaerobic effort, and have working insulin at the time. If I suspended for 45 min, that would be .75 unit I would be short, which is how much I cut my insulin to be able to work out so the math is the same. Method different.

Hi there, I am a kiteboarder and got diagnosed with Type 1 two years ago. I am still trying to find out how to balance the workout, insulin and food.

Here are my issues:

The kiteboarding sessions are 45min to 3 hours long, during this I only take a small unit amount of fast acting insulin, and eat a little higher carbs - because based on my experience my sugar levels hit major lows if I take the regular long lasting insulin.

After that heavy workout, I actually have to take a lower dose of insulin because the workout makes the insulin lower my sugar drastically.

So could somebody explain to me what the risk is of not taking any insulin? I saw that in a prior post and I thought it wasn’t that big of a deal - could you explain the side effects ?

Also, do you guys take insulin during the night?


The risk of not taking insulin occurs about two hours after you SHOULD have taken it. That’s because it takes insulin about two hours to peak. You’ll probably see a major spike in your blood sugars about that time.

A more moderate apporach is to do what you’ve been doing, take a lower dose of insulin.

As for insulin at night- Yes, I take insulin at night, but I’m on a pump. When I was taking injections I would take one of my long-acting insulin doses at night. I never took a fast acting dose at night unless my BG were over 200.