Versaclimber
The versaclimber is without doubt one of the toughest pieces of gym equipment you can ever go on - there is no rest bite, every muscle and your heart and lungs will be burning after using the versaclimber machine.
Its best to work in small intervals when starting out on the versaclimber, do what you can until your find it tough, then have a break, let your heart rate come back down and your muscles recover, then have another go.
The versaclimber is not the ideal piece of gym equipment to burn calories or assist in weight loss, its simply one of the best pieces of gym equipment to help you gain rapid improvements in aerobic conditioning.