By Therese Iknoian

Cold weather, hot weather, icy roads, humid days, late nights at work. These and any number of other things can bust the best of exercise intentions, let alone the desire to get outside for some exercise. Your savior can be a treadmill snug in the warmth and security of your home. Advantages are abundant: No waiting lines or crowds like at health clubs, no ice to scrap off the car window, no dogs to dodge, or fancy exercise steps to learn. Just pop on and walk or run. What could be simpler?

Unfortunately, drawbacks to home equipment are just as plentiful: Squeaky, wobbly, cheap treadmills don't motivate and may even break. Equipment that's too expensive keeps you waffling, never buying AND never exercising.

Buy the wrong treadmill ("wrong" depends on budget and taste), and you'll end up with a dust-gathering space hog that will nag you about your mistake like a lifelong headache. Choose the right piece, however, and you'll end up smugly enjoying every bead of sweat.

Treadmills are popular because they're easy to master, but you also have to be ready to drop at least $1,200 (and up to $6,000) to get a decent one. Don't bother first buying a cheap one to see if you'll like it because the cheap ones shake, wobble, rattle and squeak. They have unsafely narrow and short rubber treads, inaccurate and incomplete controls, and weak power. An energetic hamster could probably give you steadier power. Unmotorized ones are a strain on joints and motivation to use, plus they tend to alter how you move because you're foced to push and pull the belt along.

If you're ready to invest the cash, look for the following:

• safety lock so kids can't accidentally start the machine.
• panic shutoff, which are usually magnets or buttons you yank on or push to cut power instantly if you get into trouble.
• at least one hand rail for balance.
• minimum two-ply rubber belt for durability.
• flexible walking beds for less impact and more comfort. computerized controls for easier use and motivation.
• DC motors (they eat less power) and a minimum 1.5 horsepower continuous duty motor. Some treadmill manufacturers play games with HP ratings, labeling lower-grade motors as "peak power" or "treadmill duty." Demand the real rating.
• Try this to test power strength before you buy: Try to stop the belt rotation as it's in motion with a firmly planted foot. The machine shouldn't shudder or hesitate.
• Walkers need machines that go up to 5 mph. Runners will need a top speed of 8-10 mph.
• Inclines of up to 15 percent add variety and intensity. Make sure incline can be changed while you're exercising and doesn't mean climbing down to move a pin on a support leg.

Treadmills can be the great motivator when it's too cold, too hot, or too dark to venture outside.

© 1998 Therese Iknoian