FASHION: What’s Smart for Spring? : Flab to Steel : Home Versions of the Step Aerobics Game Promise a Low-Cost, Low-Humiliation Route to a Beautiful Body

T hat time of year is approaching--when thoughts run to flab and the perfect swimsuit body.

One of the best strategies for turning flab into muscle is the ‘90s aerobic technique--step training. Based on the simple movement of going up, down and over one stair, or bench, this low-impact exercise looks easy and fun to do. Fitness buffs swear by it for toning lower-body trouble spots.

But even these benefits can’t entice men and women who think a gym takes more time, money, effort or courage than they can muster. Now, these homebodies have no excuses. Severalsporting goods manufacturers offer step systems, complete with instructional videos, just for them.

To find out which one is best for a beginner, we went to the nearest sporting goods store, Sport Chalet, to sample at-home step systems for ourselves. (Prices may vary from store to store.)

At the top of the line is The Step, which carries the Reebok name in health clubs but is made by Sports Step. It costs $99.95 and comes with two sets of easy-fitting risers that allow steppers to increase the height from 4 to 6 to 8 inches as they increase their fitness level. Workout experts say there is no need to go higher, no matter how tall you are.

Step II, at $49.95, is roughly half the length of the original Step, with built-in risers that lift it to 8 inches. The size, perky shape and colors of this model got me stepping immediately.

The Jane Fonda Bench, $59.95, is about the same size as the Step II, but it can be raised to only 6 inches. In the video, Jane does the floor exercises, but she leaves the step training to others.

The video doesn’t use the step as much as we would have liked, and it’s not as easy for a beginner to follow as the videos included with The Step and Step II.

In May, Reebok will introduce its own step system, for $100. Increasing its height is more complicated than in other systems, and the rubberized surface of the one we tried was already coming loose. But the MTV-style video, which will be offered separately for $29.99, is terrific.

Knowing we would eventually need to add spice to our home routine, we tested some tapes available in selected video stores or through the Sports Step company (1-800-Say-Step). We responded best to those with an earnest approach, ruling out Cher’s “A New Attitude,” which is slick, entertaining and beyond beginner’s league.

We preferred Becky Tirabassi’s “Step Into Fitness,” Karen Voight’s “Lean Legs & Buns” and Voight’s “Firm, Arms & Abs,” in which she uses the step equipment on a slant for upper-body toning.

Other beginners swear by Karen Flores’ “Step into Fitness” and Marsha Macrow’s encouraging “Buns of Steel,” whose title tells it all.

Gin Miller, the fitness instructor who invented step training, says it’s a natural, cardiovascular, fat-burning exercise “that is almost military in action, so people feel relaxed. There’s no need for intricate dance movements and there are only 12 step patterns. After you’ve learned them, it’s like typing or riding a bike. You never forget them.”

Miller says step-training rules include good posture with soft knees and a tight abdomen. Clothing should be comfortable and allow perspiration (there will be plenty) to escape. You can wear special step-training shoes or any lightweight athletic shoe, such as cross trainers.

If you choose the medium-priced step system and already have the shoes and the VCR, your initial outlay won’t exceed $50, plus tax. You won’t have to leave home to turn that flab into steel. And when you do, you can head for the beach.