I'm type 1 so slightly different experience controlling it. I love spin. Just take some quick acting sugar with you. I test every 15 minutes. If you test you may want to do at the start and half way through?
When I first started I couldn't do all the moves like the standing up. You just keep on pedalling sitting down. You are in control of the resistance if the bike so again if you are flagging reduce it. No one knows what it is set on so don't worry about looking 'new'. Standing up though needs some resistance.
Do tell the class teacher you are diabetic at the start. Maybe get there a few minutes earlier so you don't have to tell everyone. Get them to show you how to set the bike up for you.
You need a bottle of water, and a towel. If the music is good it's brilliant.
Enjoy!
(Quick acting sugar - lucozade, I take a swig when I need from the tests, or 4g of sugar glucotablets. They raise my sugar by about 1 point. If new to exercise you may find the sugars increase to begin with, if that's the case a walk / jog on the treadmill or moderate pace on the bike at the end of the class may bring it down. Again I'd test.)
