Fitness. It is never easy and often can be boring. Running, pumping iron, push-ups, sit-ups...sore knees, monotony, time consuming and not always done properly.

Free-weight equipment was introduced many decades back. Still, workouts were routine and time consuming..three repetitions of each exercise. Wait. Next exercise and three more.Computers, now, have put some interest back in getting fit. Getting in shape and better health have become automated and, consensus is, more fun.

There are now machines on the market with such simple names as cycles, stairs, treadmills and climbers.

They are, however, anything but simple. Then can, at the touch of a button, take users over hill and dale, and everywhere in between and never move.

Users can ascend, descend, warm-up and cool-down. They can, in a matter of minutes, climb the steps to the top of the Empire State Building, or pedal over a rugged, mountain course.

And, points out Brent Cook, general manager of the Sport Mall, without all the boredom.

The most popular of the newest computerized fitness pieces is the aerobic stair machines. The machines, quite simply, simulate climbing stairs.

But, says Cook, "with some variety -- fast or slow, short steps or long ones...and while you're doing it you can watch television, read a newspaper, or talk with your neighbor."

When completed, the machine tells how far (miles), how high (floors), how many calories were burned and how fast the user climbed. It also, in the recommended 15 minutes, offers a good aerobic workout.

Another popular piece is the treadmill. It can, depending on the model, offer everything from a simple stationary walk to a complete hike. Programmable units can vary speed and incline, thus offering a variety in the pace and terrain.

They, too, can monitor everything from heart rate, to distance, to pace, and even offer a visual account of the route.

Another popular mechanical exerciser is called the "Gravatron." It is designed to exercise the upper body and properly programmed can assist the user with pull-ups and dips.

"It can," notes Cook, "Do almost all of the work or very little. It allows people to do these exercises that could, normally, never do them."

One of the first mechanical fitness devices was the stationary cycles. Newer models, however, have taken riding into new areas.

The programmable cycles offer slight resistance on small hills, more on steeper climbs and almost none when going down hills. They, too, monitor distance, speed, heart rate, rotation of the pedals and indicate terrain.

Climbers are different in that they exercise both upper and lower body. They simulate climbing using hands, arms, feet and legs. They, too, can monitor heart rate, resistance, pace and duration.

And there are other pieces of equipment on the market to exercise the body and add more interest to fitness.

Some of the equipment is simple and inexpensive. The more features, though, the more expensive it is.

And, as Cook noted, the more features the more attractive it is to the users.

A programmable treadmill, with moveable tread, costs about $5,000; a good climber about $2,500; a programmable cycle about $2,100; a "Gravatron" about $4,000; and a three-pace climber around $11,000.

"Besides the variety," adds Cook, "there, of course, are the benefits of the exercise. It has been found that such machines offer a good cardiovascular workout, which burns fat, increases body strength and works and strengthens the heart."

The bottom line being that the new fitness equipment adds to the interest of getting fit.