FINALLY! After 6 week plateau, 6/10 of a pound loss!

There's a big difference between a 'warmup' and actual cardio. A warmup would be 5 minutes of aerobic work and another 5-10 minutes of dynamic stretching. It's very different from 20-60 minutes of moderate intensity cardio, much less taxing.

Being a diabetic can effect what you use for energy, but only in certain circumstances. If you had uncontrolled insulin-dependent diabetes, you'd be using primarily fatty acids in the form of ketones, but only because the insulin wouldn't be able to send glucose into the cells. In that case, you wouldn't want to exercise anyway, because you'd be very sick! A person with controlled diabetes would function pretty much the same as anyone else.