How to compensate for BG spike during HIIT workouts

Hello everyone, I just found the FUDiabetes forum and am reading daily- what a wealth of information.
I’m 43, diagnosed T1D 3 years ago.
My question is: Is there anything to help compensate for a significant BG spike during daily workouts?
Workouts are high cardio and weight training (similar to CrossFit) burning 650-900 calories in an hour.
I typically start with a BG below 110, but always spike to 180-220 during and immediately after my workout. Within an hour I fall drastically to below 120 or “back to normal” with no insulin adjustments.
My concern is if I bolus before my workout, or set a temp Basel rate prior (don’t wear pump during), I’ll bottom out afterwards.
Not wearing pump for 60 min isn’t an issue as my basel rate during the day is 0.1 units per hour (because of my fitness and activity).

Thanks in advance.


Hi Gadget. Welcome to FUD!

I always take insulin right when I am starting the harder segments of either intervals or threshold work. There are certain workouts where you know you will spike. I counter the drop afterwards by taking a lot of carbs (and some insulin) when I am finished.

The carb replenishment is important for being able to workout hard several times a week. And doing the replenishment immediately after you finish your workout helps restore your muscle glycogen much faster and more efficiently than if you wait.

So it really works out correctly doing it this way. It covers the spike, and then you get better replenishment.

There is a lot about this sort of stuff in the sports wiki’s if you are interested in it.


On the plus side, the spike you see means that your workout is being effective! Otherwise you wouldn’t see the spike.