Low after exercise - how long does it last?

I was just dxd Type 2 three months ago and have lost 27 pounds through diet alone. Just this week I’ve added exercise, am walking on the treadmill 30 minutes every day. I test my bg right before and right after exercising. It usually goes down 10-15 points after exercise, which takes me all the way down to the upper 90’s. My question is, how long does it stay at that level? My average over the past three months has been around 112. Thanks!

First of all, that’s a good level! And congratulations on the weight loss. But in the end, the question is unanswerable.

It will stay there until some force changes it - eating, stress, activity. There’s no reliably predictable time.

If you were to simply sit down and wait, it will probably start to go up slightly in a few hours because glucose is building up. You’re a diabetic. On the other hand, exercise improves insulin reception, so you might go down slightly. You might keep going down until you eat something.

The only way to really gauge what will happen next is to test. Have another test after 1 hour, then again after 2 hours. Don’t eat or engage in strenuous activity in the meantime. That should give you a decent measure.

Repeat every six months. Things change, you know.


Congratulations on losing 27 lbs.! That’s fantastic.

As Terry said, it’s different for everyone. Keep testing & logging your numbers to see the pattern. How exercise effects people varies greatly. I’m Type 1. Strenuous, heart pumping exercise sends me high (liver dumping glucagon as a stress response to a real work-out), which is followed by a low that can last a while. Walking brings me down a little. Working in my garden lowers me, too, which doesn’t feel like exercise.

Hello Patricia. I agree with what they said…it really varies depending on the person, the food intake prior and the type of activities. To establish your BG trending, test and keep a log.

I am also type 2. Since I am not on insulin, I rely mostly on diet and strict routine physical activities. Personally, when I test during and after exercises (usually about 40 minutes cardio workout or 2 miles run) I would even go as much as plus 15 to 20. But after resting (stretching or breathing exercises for 10 minutes) it will lower down, in fact about less 5 from the original reading before exercising.

I also kept a log of BG level even with other physical activities such as when I clean the house, mow the lawn, do gardening, grocery shopping, do sports, or even when I run after my dogs (which I do a lot, lol). It is my guage of how much (carbs and protein) I will have to eat.

Im not sure if this will help. Good luck though.

Thanks everyone for your answers, very interesting. Terry, I’m going to try what you said, testing at intervals afterwards to see how long it stays that low. Usually I exercise right before I fix dinner, so when I eat I’m sure it probably goes up.

I’m curious about something else too. Will these lows have a positive affect on my next A1C numbers? I mean will it be slightly lower because these lows will be figuring in?

They may or may not help, how high your blood sugar goes after eating will be a bigger component though. Upper 90’s aren’t really low, maybe low for you, but are pretty much top end of where a non-diabetic would be most of the time.

The exercise will ‘stay’ with you for up to 48 hours or so depending on what you do. It basically makes your cells more sensitive to insulin so if you are insulin resistant then it will help bring all your numbers down lower for a while, not just immediately after. It’s a tricky area as has been pointed out by the poster who goes high with some forms of exercise.