Blood Sugar Prior to Starting Session

Medical Q&A [Moderated]
1

Greetings,

First, thank you, Barbell Medicine, for the information you have provided for the public.

As a type 1 diabetic, the pursuit of “physical fitness” has been shoved down my throat since the age of 7. While my endocrinologists over the years have all agreed on the aforementioned point, I have heard varying recommendations on:

At what blood sugar is it “safe” to work out?

Now, this is a “nuanced” question in the sense that LISS cardio would affect my blood sugar differently than pursuing a squat 1 @ 8/8.5/9. High intensity tends to increase blood sugars, where low intensity can lower it. When I was doing BJJ/MMA or the sort, I had to start my training at a sugar ~100-160. If I started with a blood sugar ~200, I would soon soar to ~275-300. The intensity of those training sessions, coupled with adrenaline (placebo?) I’m assuming, would skyrocket my sugars.

Now, lately, I have not noticed crazy deviations in my sugar while working out. I am not asking if it’s okay to begin training with a sugar of 180 or 195. I will. I am fortunate enough to have a CGM now, so I can catch if I’m trending too high.

At what blood sugar, above 200, would you recommend waiting to drop prior to starting training?

This question arises because I was stuck 200+ for a few hours last night (starting to realize I might need to lower carb intake during certain times of the day) and it led me to miss my training. So now, I’m going to have a bitch of a week making that day up.

I have heard from endocrinologists:

Don’t work out if your sugar is above - 150, 190, 220, 250, 300.

Meaning I have been recommended in the past to work out at 300 because: “working out will lower your sugar, just jog for a bit.”

Do you have any experience with this particular topic? At what point is it a “no-go” vs. “you’re probably fine.”

This ended way wordier than expected, I appreciate you taking the time to view this, even if there is no recommendation made.

2

Here are some good guidelines on the matter: http://care.diabetesjournals.org/con…9/11/2065.long

Specifically the section titled “MINIMIZING EXERCISE-RELATED ADVERSE EVENTS IN PEOPLE WITH DIABETES”

Individuals with type 1 diabetes should test for blood ketones if they have unexplained hyperglycemia (≥250 mg/dL). Exercise should be postponed or suspended if blood ketone levels are elevated (≥1.5 mmol/L), as blood glucose levels and ketones may rise further with even mild activity.

So it has more to do with the presence/absence of blood ketones (risk of DKA, as I’m sure you’re aware) more than any magic glucose number.

3

Thank you, Dr. Baraki.

I’ll stop stressing if I’m 200 vs. 220. I’ve got ketone strips in the mail, haven’t used those since adolescence to be honest. Generally, most diabetics I know never even check for ketones as the cause (continued high sugars) would be treated the same way as ketones. Lower BG, pound water.

What’s interesting, all the ketone strips on the market are based around the keto diet, which I find pretty hilarious. When I was diagnosed the only ketones we had it seemed were from Bayer.

Thank you for your answer and reference to the material.