Marathon, anyone?

Hi there! I am 24, type 1 diabetic and considering training for a 1/2 marathon. I use the gym close to 5 days a week and everyday it is a struggle to keep my sugar from dropping super low. Most days I leave the gym with my sugar in the 30’s-50’s. It stinks! So, I have started suspending my pod, and trying to eat something before going, but I hate having to eat so I can workout, you know? Sort of seems to defeat the purpose…
So, I’m wondering if anyone has ideas or things that have worked for you, in regards to keeping your sugar from dropping while working out. The other thing I did was chew glucose tabs throughout the workout, gag me. Any thoughts or ideas are welcome!
PS: I’m so happy to find this site, diabetes can be lonely.

What works best for me is severely reducing the basal rate about 90 minutes prior to and during my workout. I don’t think it is a good idea to completely suspend the basal for that long, as it typically leads to more difficult glycemic control later on. Exercise is also more difficult and less effective if you do not have adequate glucose available for your muscles. You also may want to consider changing your diet such that you have more protein in you a few hours before your workouts. I use protein shakes for this (0 carb) and they help prevent hypoglycemia by providing a steady source of glucose that isn’t quickly used up by the demands of my routine.

I do not do this type of exercise you are doing however so I don’t know how long you work out or what kind of things you are doing in the gym. My workouts consist of about 15-20 minutes of high intensity interval training cardio work, followed by 40-50 minutes of weight lifting.

Good luck, and trust me, this is a problem you can solve but while exercise makes controlling diabetes a lot easier when you’re not in the gym, it is doubly hard while you are there!

  1. Buy Sheri Colberg’s book “The Diabetic Athlete
  2. Join the group “Athletic Diabetes
  3. DO NOT turn off your pump when exercising. Look at it this way - nondiabetics don’t turn off their pancreas when they exercise. The problem is that turning off your pump when you start exercising will have absolutely NO affect while you’re exercising because the insulin you pump now doesn’t have any affect for nearly two hours. What this means is that two hours after you’ve turned off your pump you will have NO INSULIN on board. If you’ve just finished exercising you may also have no glucose and you’re in danger of experiencing a post exercise spike in which your liver and muscles start releasing glucose from their glucogen stores because they think there’s a ‘no glucose emergency’. So UP goes the glucose, there’s not insulin to counteract it, here come the ketones, then ketoacidosis, yada yada yada. (Have you ever felt sore all over and nauseous an hour or so after exercising? That’s ketoacidosis.)

The better practice if you’re on the pump and want avoid lows during exercise is to cut your basal rate to 40 or 50% of normal starting 90 minutes to two hours before you start exercise. Not always easy to plan, but easier if you are using a training schedule for the half or full marathon.

  1. To keep bg from dropping during exercise carry a lot of carbs with you on your long runs. It doesn’t have to be tabs. Running gels are fine, if you find one tasty enough. Pretzels work. If you don’t like eating, bring some gatorade instead of water or use a 50-50 gatorade/water solution like I do. You should always have something to hydrate yourself with on a long run (i.e. runs over 30 minutes).

These are the things that work for me. Different strategies may work for you. You’ll have to experiment and try them out. While you’re doing that, remember to always keep your meter handy. I never run without one.

Also know that you are NOT alone, even though diabetes can be lonely. I was surprised to find the number of diabetic runners out there. There are lots of places to get good advice. Almost every running website has a forum for diabetic runners. (I’m a member at And there’s the Athletic Diabetics forum here, as well as the “Diabetics who run marathons” forum.

So, get the book, and don’t turn off your pump. EVER.

Good luck in the 1/2 marathon. Which one are you running? I"m doing Carlsbad on January 25.


Kelly, I feel your pain!! I experienced the EXACT same thing while running. It drops me like a rock and I hate having to eat beforehand, but had no other choice. I was going to recommend asking Terry about it because he always has great advice on running, but I see that he has already replied. :slight_smile: I second everything he recommends!!
I will also mention that I’ve noticed that the time of day makes a big difference in my workouts. When I run races, they are always in the morning and I don’t go nearly as low (if at all) during a race than I do when training at night. I think this is just the dawn phenonmenon, but part of that could also be from the adrenaline of the race. So you might want to run a 10k or something before your 1/2 marathon just to see what your bg does (plus it’s good for training!).
Good luck and way to go with the 1/2 marathon!!

Hi Kelly!

I’m new to the group here, but I have type 1 and just completed a half marathon this summer myself, so I thought I should add my two-cents worth :slight_smile: I am not on the pump, but can basically second oneless and Terry’s suggestions of reducing your basal amount. For me, without the pump, that just meant reducing my Lantus intake, especially on those days when I would be doing my long runs. Even the difference of just 5 units in my case made a significant difference for me. I usually also found that I had to eat some moderately complex carbs, such as a granola bar, prior to the workouts as well. At any rate, the half-marathon went off without any problems, so I can definitely encourage you to go for it!

Kelly : instead of using Dex 4 tabs, try Dex Liquid blast ( 15 grams per 2 oz bottle ) ?? I received a sample …new on the market here in Canada.I am a 1/2 marathon walker, will be in Disney World, Jan. 10.with Team Diabetes Canada.Do not forget electrolytes . Available without sugar.I also set my pump ( basal ) at 45 percent as recommended by others if I do more than 5 k .For me it is best to start out a bit higher ( around 180 , just after breakfast ) …the exercise will bring it down quickly .I eat Glucerna bar , cut up in about 16 pieces , during my 1/2 m. training …seems to work most of the time .( I do not want to loose any weight )
I did 18 k yesterday and had the temp. basal set for 11/2 AFTER my completion( 45 percent ) , however my sensor showed a rapid increase; I cancelled the temp.At about 5.30 pm a low ( maybe I should not have cancelled the temp. too soon ???)…not unusual for having done this type of excercise and duration to have a low up to 30 hours later …moral of my story …lots of finger pokes AFTERWARDS.
Go Runner Go !!

Terry, thanks so much for the ideas. You are extremely helpful! You know I hadn’t thought of the fact that “regular” people don’t turn off their pancreas when they go for a run. A good point.
The thing is though that the only times I don’t drop super low after working out is when I have suspended the pump for the hour before the run and the time during the run and I have my sugar in the mid 200’s before the run and then I’ll turn out around 80 after the run. I think the only thing I have experienced is a somewhat higher number the next morning. It’s such a puzzle, isn’t it? Put this piece in, take it out, try a different one. Do you think it’s wrong to get your level up (like I said, mid 200’s) in order to run?

I’m going to do the Lincoln 1/2 marathon in May.


It’s not wrong to get your level up. Some might say it’s essential. I try to start a long run with an elevated BG, but I don’t generally TRY to get it up. If it’s low (i.e. say below 120) I eat something first, like an apple or PB sandwich. If it’s under 90, I don’t run, but eat something and wait for it to go up. That’s the only case where I TRY to get it up, and then only when it’s a training run that I really shouldn’t miss. Otherwise, there’s always tomorrow.

Be careful though about starting too high (over 280 or 300). It’s led to ketoacidocis in my case. I’m not sure of the mechanics/biophysics behind it, but you can look it up on the web or in the book.

Good running!

It also hinders your performance to train with blood sugars that high, and makes staying hydrated quite difficult. I will not work out if my blood sugar is over 200, certainly not 280 or 300.