Spin Class No No's

[Dogmama]

Hi.

New to the boards here. Interesting and great reading so far regarding spinning.

What's your opinion on doing crunches on the bike(standing run and bending forward with hands in position one)?

Personally, I cant stand doing push-ups or crunches and even though it's only once a week from one of the instructors i take im going to stop doing them.

Also, spinning at a high resistance/low cadence with your hands on your hips or behind your back?

Thanks.

Both moves are wrong & potentially dangerous.