At what bg level do you feel safe to exercise without going low? For me it’s at lease 180-200 for a 30 minute walk on the treadmill. I dial down my pump but, sometimes I even have to suspend it.
It all depends on the circumstances. My cardio is high intensity interval work and I will drop over a 30 minute session, but I’m comfortable starting around 140 with no basal adjustments. When I was doing longer, slower stuff, I’d have to start closer to 180, but I wasn’t on the pump so I didn’t have the option to adjust basals accordingly. For weight lifting, I have no problem starting in the 60s and I expect my BG to rise a bit from there.
Interesting that you would say that about wieght lifting. When I was doing weight lifting my bg’s would go up even when starting at a low level. I read recently something about this. How cardio will make it drop but weight lifting will bring it up.
I have to be well above 200 mg/dl. I usually work out for 60 minutes. I can expect a drop of about 90 mg/dl per 30 minutes of biking or about 60 mg/dl per 30 minutes of walking on the treadmill. The effects also stay with me for the next 6-8 hours and I will continue to head downwards so I usually have to dial back on my basal rate.
Yeah, not always the case for everybody, but fairly common.
I use a cgm but not a pump (yet). Weight lifting also raises mine, though I can’t weight lift well when I’m already low. For cardio I don’t really drop a lot especially if it’s more intense (like sprint intervals) but for longer slower runs, I’ll start as lows as the 80s if I’m stable and will just eat carbs periodically. Though I also try to run when I don’t have any or very little active bolus.
In the beginning, my plan was very similar to yours. But now I aim to be about 100-150 immediately before my run. My typical plan is to run right after a meal, so that I don’t need to bolus or fuss much with basal. I’ll usually be headed up by the time I’m out the door, but will quickly stabilize and be heading slowly back down 20-30 minutes in. Without food, I wait at least 2-3 hours after my last (significant) bolus and will cut my basal for 30-60 min before I head out. On the low end of that range, I’ll pop a few glucose tablets but won’t necessarily wait for my bg to go up before I head out. I know that they’ll give me a little bit of breathing room so that my basal cuts can sink in completely.
But none of that is an exact science, so I really rely a lot on my CGM. Once I’ve started out, I won’t usually turn down my basal much more than what I planned because it’s usually too late. And I’ve learned that if I cut too aggressively that I’ll end up high (say, >1-1.25u total). As soon as things creep downward (~100, depending on how fast), I’ll use some glucose gel. Sometimes it kicks in before I feel it, sometimes it doesn’t. But I rarely have to stop completely.
I’d say that about 1/2 of the time I end up down a tad, like 50-75. About 1/3 of the time I end up in my target range. And whatever the rest is (not good at fractions) I end up a bit higher than I’d like. So I think it depends on how comfortable you are. My plan usually keeps off the really bad lows, and with hypo-unawareness 50s to me feels fine except that my legs feel like lead! If I were back in the days of being more sensitive to the symptoms, I’d probably edge quite a bit higher.
Tom, I also try to walk right after eating lunch! I have more energy at that time and I like being able to cut my bolus.