Upper limits?

Wednesday morning, I woke up at 5:15am with a blood sugar of 219, thanks to a serious steak dinner the night before. I didn’t bolus, but suited up for the gym, made a cappuccino, and went to a kickboxing class for an hour. I came home to a friendlier blood sugar of 150mg/dL

We all know that working out can send you low sometimes, and that you’d never want to workout when you’re already low. But highs? I have quite the upper threshold for working out with a high blood sugar. I’d have to be over 350mg/dL and spilling ketones before I took my gym shoes off and canceled a workout. In fact, I’mmuch more likely to take a half unit to bring down my BG over the course of the workout more quickly rather than sit one out.

If you read through a general guide to diabetes though, know working out with a high isn’t recommended. For one, a workout + high BG is a good recipe for dehydration – your body is already working overtime trying to keep water in while getting sugar out. And two, if you do have ketones, you can really push yourself over the edge by working out when you don’t have cells with ready energy to get you through it. Your body will burn proteins and fat and kick up your ketones more.

The thing is, most of my highs are food induced, which for me doesn’t usually produce ketones. And I tend to look at workouts as an opportunity to bring down a high blood sugar instead of a risk for further damage. But could this outlook get me into trouble? I’ve not had a problem with it ever that I can recall, but I also know it goes against HCP recommendations.

Do all of you have a high number that you won’t workout at? Or do you always push through?

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With a few caveats, I just go and workout when I have high BGs unless it’s due to lack of insulin (not just under-bolusing for food). After all, exercising is a great way to bring down the highs and to make the world a more pleasant place for me and others. (I get wicked crabby/moody when my BGs get over 250, and exercise always makes me feel better in general. Win-win!)

But I won’t do it if I’m sick (and therefore insulin resistant) or already dehydrated or having insulin delivery problems. That’s where I draw the line.

I have a very difficult time figuring out WHY I’m 300 or higher. I have rarely been able to say, “that’s because of the cheesecake I ate at midnight.” So, I’m a little more cautious, because I know my FIRST response when exercising is that my BG goes UP. It usually starts to go down after 15 or 20 minutes, but until I can explain why I’m so high, I don’t exercise at over 300.

What I’d like to know is what is a good BG to exercise at for a good 45-minute brisk walk? (I know, YDMV, but is there a number that high-octane athletes aim for BEFORE they work out?) I’ve heard that some aim to be at a certain range over optimal BG before a challenging workout.

Contrary to the guidelines you mentioned, I’ve never skipped exercising for a high blood sugar. I’ve always had good results from a little insulin + exercise. Often feel much better afterwards too!

Tim I think some of the super athletes prefer to start around 150-200mg/dL. As you said theres lots of variability, but I’d it were me going for a brisk walk that long I’d want a bg around 150.

For me it depends on the activity. If i’m going for a long run I’ll set out high (up to 200) and be borderline low by the time I get back. But if i’m playing soccer I’ll take some insulin first because soccer games, unlike a normal run, increase my BG in the short term. I guess it’s the adrenaline.

I agree with most of what’s been said here. When I’m high, it’s usually from food, like you and Jeff said. If that’s the case, exercise usually helps me get back down (even though I often feel yucky while exercising).

If I’m high for some other reason, like a possible pump/infusion site problem, then I’ll back off. But that doesn’t happen very often.

Great question!

I exercise when I have a high bg. Yesterday I was 191 and I went for a fast-paced walk, which brought my bg down into the normal range. You are right, it’s important for each person to know how our blood sugar responds since each one of us is so different.

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