Shouldn't be a problem, long as you "respect" the machinery of the gear mechanism by being as gentle as possible.
Just remember that the pedals have to be moving forward for the gears to work and they will work best with minimal pressure on the pedals. So it's always best to try and anticipate when you will need to change and do it in a relaxed manner.
Not always possible when you turn a corner and there's a bloody great hill ahead !!
