[Brian23]

What is the reason people say not to exercise if your above 270 mg/dl. I usually jog when my sugar is high to get it to come down. Just wondering what exercising does to you when your sugar is high?

[princesslinda]

I've read that if your blood sugar is over 250 and you exercise, you run the risk of spilling ketones into your urine.

[lilituc]

Another problem is that you're not getting enough glucose (due to it being stuck in the blood) so your liver dumps more, causing your bg to go up more.

[Funnygrl]

It's mostly for people who make no insulin. If you have some endogenous insulin production the exercise will usually bring you down.