What should my target BS be while I'm weight lifting vs. cardio?

By Cattaztrophie Latest Reply 2014-12-01 12:10:53 -0600
Started 2014-11-29 18:36:03 -0600

I sincerely hope I can get some answers while I'm still motivated to exercise. My endo told me a while back that my sugars need to be within a certain range while I work out, otherwise I won't gain any muscle, and I'll just burn through energy. I understand that sugars tend to drop while doing cardio and raise while lifting, but I can't seem to find anything online that tells me EXACTLY where I need to be for optimal performance. Yes, of course I'll speak to my doctor about this, but my next appointment isn't until January and I want to get fit now. Actually I want to get fit a while ago buuuut the intimidation factor stopped me.

6 replies

Nick1962 2014-12-01 12:10:53 -0600 Report

After 7 years of doing this now (well, 6 successfully) I can give you the one rule of thumb and that is to be “mid-range” before exercise no matter what type. I think you may have misunderstood or misinterpreted your endo’s advice regarding energy. There is no way to micromanage your body’s systems like that unless you’re on a very regimented and consistent diet, as well as exercise program (and we’re talking a gym rat here). And of course this rate of metabolism will change as you get a little more fit, so it’s a moving target. How and what energy gets burned is determined by what source it’s being taken from. Higher carb/sugar sourced energy will burn away quickly, then you’ll be burning reserves (body fat). You won’t gain any muscle without protein and fiber to build off of.
My numbers go up during any exercise, no matter what type. It’s the “fight or flight” response – or “liver dump” my pancreas does to make sure I have the energy needed. They go down about 15 minutes after I’m done. A pre exercise snack for me is a higher protein one to feed muscles, since Mr. Pancreas takes care of the rest. I’ve had to use a higher carb “after snack” to prevent crash.
All that said, I did have to really understand my calorie in/calorie out ratio as well as my energy forms to balance weight loss and prevent muscle loss. As I got in better shape, and in a pretty strict daily diet and exercise routine, this changed constantly because my levels improved. I can now eat “normally” and exercise reasonably without repercussions. All the info you’ve been offered so far is what I had to learn. You do need to know the “why” to some degree, because it’s not just as simple as picking a target.

GabbyPA 2014-12-01 06:59:54 -0600 Report

I don't know about how the optimal performance works. I had never heard that there was a place like that in our levels.

The only guide I have found for exercise is that if you are under 100 you need to eat something before starting. And if you are over 300 you need to get your levels down before starting any kind of exercise because that high of a number may increase instead of decrease.

Doing anything, even if it's not that optimal performance, is better than doing nothing. If you wait until January to get your answer, you loose the opportunity to get things started now. Think of this as your build up time to the optimal training you desire. You have to start somewhere.

vensa 2014-11-30 14:02:56 -0600 Report


"My endo told me a while back that my sugars need to be within a certain range while I work out, otherwise I won't gain any muscle, and I'll just burn through energy."

With a bit of searching the net, I found the following input in this article (refer link below) "…to maximally lose body fat: maintain your blood sugar level between 70 mg/dl and 110 mg/dl".

I don't know if the above answers your question, but it helped me look around and to start thinking. I was only aware until now that optimal heart rate range has direct correlation with fat burn. By increasing heart rate, you'd only burn food and not body fat. All the best!

Type1Lou 2014-11-29 18:58:39 -0600 Report

You might want to take a look at Gary Scheiner's book "Think Like a Pancreas." He is an exercise physiologis and CDE (Certified Diabetes Educator). He also has a Facebook presence and I believe offers athletic training. In reading his book, which has become my go-to manual, he explains that it is not unusual for BG's to rise when working out anaerobically or during competition…it explained why my BG's went up after sessions of weight-resistance training.

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