Lows and highs with exercise

I want to start working out again but I have a hard time regulating my blood sugar with so much activity. I either go low when working out or I’ll eat a snack before exercise and not give insulin for it and then my blood sugar is too high even with being active. I have the same problem when I decrease the amount of insulin I get before working out. I feel like there is no happy medium. It’s like why work out if you have to keep taking breaks. Why workout if you’re going to have to eat during and after? It’s so frustrating. What should I do?

There was a discussion on this topic a couple of weeks ago in the group “Athletes with Diabetes”. Here is a link to that discussion:


If you need some help understanding what is said, let me know. Some of the things said in the discussion could be confusing to a “newby”

The discussion Dennis mentioned is a good one to read on this topic. I have some tips based on my own experience too. My blood sugar drops like a rock when I exercise and I got frustrated the same way you did. I kept trying until I found what works for me and even on days when it gets frustrating give yourself credit for exercising at all, it is better than sitting on the couch :slight_smile: I noticed if I have any insulin on board aside from my basal my blood sugar tanks. I just saw some of your other posts so I know you’re not currently on a pump but for me this is what I’ve discovered. The only way around this is to exercise shortly after I wake up and if my BG is above 130 I exercise as normal. If it is lower than that I use a chart in the book “Pumping insulin” and eat the number of carbs that is suggested. Each person is different but it works really well for me. According to the chart for my normal work out I need 25 additional carbs so I found a protein bar that has exactly that amount of carbs and I eat that before I work out without taking insulin for it. I am not a morning person but I’ve found that this is the best way to exercise safely and effectively. I watch my dexcom and with this method on the majority of days I do not see any major swings in either direction. I have to tweak it occasionally as with all things T1D related but it was worth the effort of trial and error because I feel so much better when I get my heart rate up each day. I have had T1D for a long time and I can relate to a lot of things you’ve said in your posts whether it be from now or in the past so feel free to contact me!

@Nstroh, so glad to hear you found some relief and a plan that works for you!

@ktlarmore03, honestly, the insult to injury for us is that any attempt to work out can easily be met with the need to “down a coke” or pass out! if I can offer any advice it would be this - go slow, if you are good with adjusting your own insulin: try to understand the issues with blood sugar control you have now. once you can predict your blood sugar, then try to take a little less insulin and work out to get your blood sugar down to the normal range. this strategy keeps you from having to take calories for lows, reduces your total daily insulin, and you get exercise.

exercise within 3 hours of a meal shot can get you in trouble, because mad-made insulin hangs out for 3-4 hours. Sometimes I “bolus half” for a meal and then work out. works for me but be careful and have carbs with you just in case - good luck!

I am on a pump, so what I do is turn down my basal rate pretty substantially before I exercise. Then I take my CGM and glucose tabs with me, and if I get even a hint that my BG is going down (from the CGM or just from how I feel), I have some glucose. Usually I leave my basal lowered for an hour or so after exercise. It doesn’t always work, but it’s the best approach I’ve found.

Unfortunately, it requires a lot of trial and error. For my bike rides, I adjust my pump basal rate to 35% and usually eat a snack (2-3 fig bars) before I head out (unless my blood sugar is elevated). I always have something with me to eat every hour like an energy bar and carry 1-2 tubes of glucose gel in case I get low. I’ve given up carrying my CGM with me since the accuracy gets really bad while I ride. If I’m on a long ride (60-100 miles), I’ll carry a small blood glucose meter. The majority of my rides go pretty well but sometimes I will get low and it takes some time to rebound. Also, don’t forget some type of emergency id (I highly recommend RoadID).

I know it’s hard but incorporating exercise into your routine will be worth it. I’ve had T1D for 39 years and been cycling for almost as long. I’ve kept my diabetes under strict control and I’ve shown no signs of any complications. Best of luck.