Don't let T1D ruin your gym session...
There's nothing more frustrating then lugging yourself all the way to the gym, only to have a hypo half way through your session. Any form exercise poses a risk of hypoglycaemia with diabetics, but that doesn't mean it has to happen. From personal experience, only cardiovascular exercise has ever made me go hypo, not weight training.
Over the years I have fine tuned my approach to exercising with T1D and have successfully managed to avoid gym hypo's for a long time now.
Here are a few ideas to get you started...
Avoiding cardio hypo's.
Always test your blood glucose before you begin a cardio workout. It will allow you to make any adjustments before you begin.
Being on a pump allows me to adjust my basal dose on the go. I always set a decreased temporary basal rate up to an hour before and two hours after exercising.
If you find your blood glucose is on the lower side of normal before you begin, eat something small to avoid a hypo.
Try not to eat foods too heavy in carbohydrate hours before you exercise. If it requires a large dose of insulin, I've found the chances of going low to be higher.