Overview

Many people exercise with fitness machines such as treadmills, stair-climbers, stationary bikes, and cross-country skiing machines. These all offer aerobic exercise. They may also strengthen muscles.

Fitness machines can be great for exercising when the weather is bad or days are short. You may also like the fact that these machines let you control the intensity of your activity. They may tell you your heart rate, calories burned, or miles covered. Fitness machines are safe and handy, but they can be boring. Listening to music, watching TV, or exercising with a friend may make it more fun.

Treadmills.

Treadmills let you walk or jog while seeing your time, distance, and speed. Many have adjustable inclines to provide a greater challenge when you want one. The treadmill should have handrails (located in front) to help you keep your balance or to steady yourself now and then. But you should not hold onto them during exercise. It's better to swing your arms as you walk or jog and to use the handrails only when you need them.

Stationary bicycles.

These work much like regular bikes. Many have computers that track your workout. Some have programs to simulate real bicycle courses. These extras aren't needed, and they aren't as important as having a bike with a good overall design. The bike should pedal smoothly and have a comfortable seat. You should be able to adjust the seat to your height. If your seat is too high or low, you may have knee or hip pain. Try to have a slight bend in the knee at the bottom of your pedal stroke.

Cross-country ski machines.

These machines are very good for burning calories. They can help you build both upper- and lower-body muscles. They also put little stress on your joints (low impact). But they require coordination. They may tire you sooner than other machines, because they use muscles in both the upper and lower body. If you are new to these machines, start slowly (5 to 10 minutes a session). Bit by bit, do more as you are able. Look for models with pulley systems for the arms (rather than poles that you pull) and adjustable parts.

Stair-climbers (stepping machines).

Stair-climbers are similar to ski machines, but they work only the lower-body muscles. They are simpler to use than ski machines, requiring no special coordination. Beginners should start slowly. Bit by bit, you can increase intensity and length of time on these machines. Keep good posture, and avoid leaning on the handrails.

Elliptical cross-trainers.

These machines combine elements of treadmills, stair-climbers, cycles, and cross-country ski machines. Some machines have arm resistance to work both the upper and lower body. Like ski machines, they require some coordination and may tire you faster than other machines. But they give a very thorough aerobic workout along with some resistance training.

Buying a fitness machine

Advertising for fitness products often promises large gains with little effort. This is a promise that sounds good but is rarely true. Before you buy, think about these tips.

• Be sure you already like the activity.

  A machine or device probably won't make you like an activity that you dislike in the first place.

• Avoid products that are available only through a television offer.

  You won't be able to "try before you buy."

• Test a machine in the store before you decide to buy it.

  Make sure it feels right to you. Sometimes the more expensive machines work more smoothly and make exercise more comfortable and fun.

• Talk to an expert.

  Get the opinion of a trainer or experienced person at a health club, YMCA, or other fitness setting about the equipment you are interested in.

• Think about whether you really need a fitness machine.

  Many products promise to help tone and develop muscles in the belly, thighs, or buttocks. But you can strengthen and tone these muscles without special devices. And most devices don't make it easier or safer than doing exercises on your own.