Are Eliptical Machines Bad?

An elliptical machine is a stationary exercise equipment that combines the upright posture of walking with the circular movement of cycling. Some machines are also equipped with upper body handles or poles that allow you to exercise your arms as well as your legs. They are not necessarily bad--in fact, they confer quite a few physical benefits--but they should be approached with caution.

Benefits

Elliptical machines can be classified as a non-impact exercise. This is defined as an exercise in which the legs do not strike the ground. Instead, elliptical machines utilize a smooth, continuous rotation of the legs. They are therefore less stressful on your knees, hips and back than full-impact exercises. In this capacity, elliptical machines are actually a good alternative to other activities such as running that may wear down tissue over time.

Bone Health

Elliptical machines are also quite good at building bones. Like muscles, bones become stronger in response to exercise. Young men and women who exercise regularly achieve greater peak bone mass and density than those who do not. Exercise also prevents bone loss later in life, which could otherwise lead to falls and fractures. The best exercises for your bones are the weight-bearing kind, in which your legs bear against gravity the weight of your body. Elliptical machines classify as weight-bearing.

Expert Insight

Elliptical machines can work well when utilized properly, but the danger is that people may expect too much out of them and fail to get a proper workout. In a 2002 issue of the magazine "American Fitness," Thomas Altena, a professor of nutritional and exercise physiology at the University of Missouri-Columbia, found that the physiological responses associated with elliptical machines were actually no better than treadmill exercises, in spite of the fact that they're supposed to exercise more muscle groups simultaneously.

False Readings

Another way in which elliptical machines may over-estimate their own worth is by giving a false reading. A study by researchers at the University of Pittsburgh found that, on average, the calorie counters on elliptical machines gave a reading that was 31 percent higher than the number of calories actually burned by participants.

Calories Burned

Many elliptical machines use a simple algorithm that only takes into account age and weight to calculate calories burned. However, gender, height and body composition also influence metabolic rate in different ways. There are obvious limitations to calculating metabolism using only a few variables and a mathematical formula, but elliptical machines, in their simplicity, may render a false impression that is far different from reality.