Step Machines
Step machines provide a fairly demanding workout, because you must lift your bodyweight against gravity throughout the training session. If you have difficulty climbing stairs this is not the best choice of indoor equipment, but if you desire a more challenging form of exercise it may be ideal.

When performed properly, meaning with an erect body posture and without leaning on your hands or arms, stepping provides excellent exercise for your legs, thighs, and hips. Leaning forward reduces the exercise effectiveness and can cause damage to the nerves in the hands and wrists.

Motorized step machines are typically durable enough to withstand the bodyweight forces encountered with every leg movement. Unfortunately, non-motorized steppers generally lack the sturdy construction and functional capacity to hold up satisfactorily under regular use.

If you are pretty well-conditioned and can afford a well-constructed motorized step machine, then you should attain much physical benefit from this indoor activity. Otherwise, you would probably be better off with a different equipment selection.

Rowing Machines
As an overall exercise, it is hard to beat rowing. In addition to the aerobic benefits of this vigorous physical activity, the rowing action involves the muscles of the legs, thighs, hips, lower back, upper back and arms. Although rowing requires quite a bit of lower body and upper body coordination, most people can master the action with proper instruction.

If you are not reasonably fit, rowing may be a little too physically demanding for a beginning exercise activity. Also, if you suffer from low back problems, it may be best to choose a less stressful exercise.

From a practical perspective, rowers that use wind resistance are much more realistic than those that incorporate hydraulic resistance. Although rowing machines are relatively affordable, most models require more floor space than cycles and steppers.

Ski Machines
Like rowing, cross-country ski machines involve both upper body and lower body movements. They also require a learning curve to master the coordinated arm and leg actions. The overall effect is an excellent aerobic workout, with very low impact forces. Nonetheless, experience indicates that this is one exercise you should feel comfortable performing before you purchase the equipment. Cross-country ski machines can be reasonably priced but they do require a fair amount of floor space.

Riders
The so-called riders that have been highly-advertised and extremely popular over the past few years generally require too little effort from a cardiorespiratory perspective and cause too much stress from a musculoskeletal perspective. More specifically, the repetitive flexion and extension of the hip and back presents unnecessary injury risk, and is certainly not a recommended activity for persons predisposed to low back or hip problems.

Summary
In the final analysis, the best exercise equipment is that which you are most likely to use on a regular basis. Just be certain that the activity you select emphasizes rhythmic action in the major muscle groups and has a low injury potential. If you are just beginning, consider that simpler may be better in terms of the exercise movements and performance requirements.

Wayne L. Westcott, Ph.D., is Fitness Research Director at the South Shore YMCA in Quincy, MA., and author of several books on fitness including Building Strength and Stamina, and his most recent publication, Strength Training Past 50.