Oh, I agree. I used to work at a gym and I'd work out there, trading every other day doing cardio & calisthenics, and then weight lifting. The trainers explained all this about the muscles and all. I had to use a lower temp basal rate on my pump when weight lifting, plus take in protein after the work out.
[quote user="Ginger Vieira"]
So this is VERY normal! I am a competitive powerlifter (personal site here) and I write for www.diabeteens.com.
This is what's happening:
When you do cardio, you burn glucose because your heart rate is rising and that's the form of fuel your body goes to first.
When you weightlift, you BREAK DOWN muscle (which is good, because it grows by repairing itself later), but there is glycogen (a form of glucose) in that muscle and it basically gets released into your blood stream, which makes your blood sugar higher. Also, some hormones, like cortisol and growth hormones, rise while you weightlift because of the stress of the exercise (but that's okay too.)
So, what I do is I WEIGHTLIFT FIRST and then do cardio after because the cardio will help bring you back down. Also, if you do cardio before weights, you burn up the glycogen and you don't want to weightlift without enough glycogen in your muscles. You need it.
Before lifting, I check my blood sugar, I want it to be between 100-160, and I don't take extra carbs and reduce my insulin because I know it'll go higher after lifting. After I lift, I'm often around 180, sometimes, after a really really hard workout, I might be up over 200, but not for long.
SO..HOURS AFTERWARDS your blood sugar DROPS because your muscles are repairing themselves but sucking all the nutrients you eat and the sugar in your blood to your muscles for fuel!
So I always eat a protein shake RIGHT after my workout and generally I take insulin for this, because 50% of the protein you eat if it's over 20 grams can be converted to glucose, and you want the insulin to carry that glucose to your muscles. But the meal I eat three hours after that, I will reduce my insulin dose for because of that delayed effect on my blood sugar.
If you're experiencing a low within an hour after your weightlifting, you need to EAT right after you workout (EVERYONE SHOULD ANYWAY so your metabolism doesn't drop and your muscles aren't starved, preventing them from growth), and reduce your insulin dose for that meal.
Does this make sense?