Originally Posted by Sincitycycler
No sport in the world burns more calories/hour - it's been documented and is why alot of the exercise machines at the gym are patterned after the activity.
Elite cyclists and XC skiers burn the same amount of calories per hour, so I've read. Makes sense, the limit to performance is the cardio system, not the number of major muscles used.
Exercise machines at the gym are good for people who haven't developed enough endurance in their legs to prevent early fatigue.