Sometimes I feel as if I’m an expert sitter.

Nothing so interesting as watching babies or dogs or homes — no, I just happen to have a sedentary job that’s predominantly meetings, reading, thinking, and writing. I stand when I can (for general health, not fat loss), but end up sitting when I really need to concentrate.

While I’m sitting, blood sugars are generally stable. So when I do significant movement, I really see it in my blood sugars.

Why should you care? As with food, this impacts you no matter whether you’re diabetic! I see my body burning fuel when my blood sugars drop, and I see a stress response when they rise — diabetic or not, your body is reacting similarly.

So, here’s a look at some of the most significant and interesting impacts to my blood sugars based on movement. I’m skipping the things with predictable impacts. Normal, 45-minutes-slogging-away-on-the-treadmill type of cardio, for instance — predictably, it drops blood sugars steadily because of steady exertion.

That is, if you can stand 45 minutes on the treadmill.

1. THE BIGGIE: Very low-intensity steady-state activity — drops blood sugars

We’re talking strolling, unhurried cooking, (un)packing, household chores — things that no one would call “exercise.” I even use slow (i.e., 2.8 mph or slower) walking in tandem with or in lieu of extra insulin when I can to lower my blood sugars. Just 20 minutes of walking can drop my sugars significantly (too much, if I’m not careful).

When you perform low-intensity activity, your body’s glucose utilization rises — in other words, your body uses more fuel. No kidding, right? 😉

Non-diabetics, your body adjusts automatically for this. Diabetics, you have to lower your insulin levels well ahead of time to account for the drop (or only do this sort of activity when your sugars are somewhat elevated). No matter who you are, it’s GREAT to engage in this sort of activity. It’s physically easy for most — you might even be able to stream movies/TV while doing it . . . not that I do that . . . — and that makes it even better.

2. High-intensity intervals — raise blood sugars

High-intensity interval training (HIIT) is cardio, to be sure. We’re talking repeated cycles of 15-45 seconds of balls-to-the-wall, you-may-topple-over-and-pass-out exertion, followed by 30-90 seconds of active recovery.

So shouldn’t it lower my blood sugars? After all, by the 10-minute mark, with sweat running down my face and heart beating out of my chest, I’m usually appealing to the Triforce for the power and courage to continue and the wisdom to know how far to push without tossing in the towel prematurely.

But no — blood sugars usually rise. Intervals cause the body to increase the production or secretion of glucose, catecholamines (adrenaline being the major player here, I’d think — more on that in part 3 of this series), growth hormone, and cortisol. All of that contributes to a rise in blood sugars, and that rise can be hard to tame.

It’s a completely different story six hours later, though, when my body decides I’ve worked out and my blood sugars drop.

I am not amused, body.

3. Heavy weightlifting — raises blood sugars

HIIT by another name. Same effects.

BUT WAIT!

It couldn’t be that simple, right?

4. HIIT or heavy lifting within an hour of eating — lowers blood sugars

Heavy as my stomach may feel, I often push myself to the gym within an hour of eating on lifting and interval days. By doing so, I don’t get the blood-sugar spike I’d otherwise get — it seems to pretty much negate the stress response my body otherwise has to high-intensity activity.

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We’ve now covered the major, maybe unintuitive impacts of certain foods and exercise on blood sugars. Part 3 — all the other weird things that impact blood sugars — is up next!