Part stair climber, part treadmill, part stationary cycle, elliptical motion trainers are a hot aerobic machine.

Your legs travel both forward and backward in an elongated circular movement. On some models you also pump poles back and forth for an upper-body workout.

Also known as cross trainers, these machines exercise your bones as well as your heart. They provide a weight-bearing activity that still goes easy on the joints.

Various models have options that add variety. In addition to adjusting duration and speed, you can change resistance, direction and often the stride and the incline of the ramp. Some models have programs that focus on certain goals, such as losing weight or toning gluteal muscles. It’s also possible to improve balance and posture by not relying on the hand grips.

• Elliptical trainers provide a good break from the pounding of other aerobic activities.
  
  
• They’re easy to use.
  
  
• This exercise is an excellent cardio workout and a decent way to lose and keep off weight.
  
  
• While exercising you can watch TV, catch up on your reading or spend some time with your daydreams and thoughts.
  
  
• People with joint or bone problems may benefit from this low-impact exercise, though they should get a doctor’s OK first.

• The calorie counters on most machines exaggerate your effort.
  
  
• Poorly designed models will make you feel as if you're stumbling downhill on your tiptoes.
  
  
• Some people consider this exercise tedious.
  
  
• The upper body aspect doesn’t add much in the way of calorie burn or strength development.
  
  
• Some people experience numbness in their toes when they elliptical train for longer periods of time.