I've injured my knee a bit and it has taken me off my bike for a little while. Someone suggested using a hand cycle at the gym to keep up cardio and calorie burning. How good is a hand cycle for that? Is there something that is better?
According to AskTheTrainer.com, on their review of cardio machines, they say... "Hand ergometers can actually get your heart rate up faster than leg cardio machines because your arms are closer to your heart than your legs." They also say it's not common because it is boring. That is the only downfall they mention.
Source - http://www.askthetrainer.com/best-cardio-machines.html - Almost at bottom of the page.