Getting in shape can be an expensive proposition when you consider the cost of health club memberships and state-of-the-art home exercise equipment. And while these fitness options have their perks, the investment required keeps many individuals from pursuing a healthier lifestyle.

   "Cost doesn't have to be a roadblock to exercise," states Judi Sheppard Missett, founder of Jazzercise, an international dance exercise program. "I think the public gets caught up in the images they see portrayed in the media of full-service health clubs and fancy machinery. Actually, you can build a very effective home gym for under $200 with a few carefully selected, inexpensive pieces of equipment."

   One favorite piece of equipment is a resistance ball. Made of brightly colored synthetic vinyl, the 21- to 25-inch inflated balls are the latest fitness prop to roll through the exercise industry. Used correctly, resistance balls hone motor control and balance skills by challenging the muscles which stabilize the body. Physical therapists have used resistance balls for years to strengthen and stretch the muscles of the body to meet the demands of daily movement. The balls are extremely affordable, costing between $20 and $28.

   Aerobic steps are another great option for home workouts, they're lightweight, easy to stash out of the way when you're not using them, and there are plenty of exercise videos on the market today that feature step workouts. Steps cost between $20 and $70 and can be found at most sporting goods stores.

   While you're there, pick up a pair of lightweight dumbbells and a resistance tube. Both of these items do a great job at toning and strengthening muscles without making a huge dent in your wallet.

   Your home may already be equipped with additional exercise equipment as well. A chair can be used throughout a workout. You can sit in it while doing bicep curls with your dumbbells or resistance tube, or stand behind it and hold the back for support as you perform squats or calf stretches.

   Likewise, a rolled up towel can be strategically placed to support your lower back as you do sit-ups or hamstring stretches and 16-ounce canned goods can substitute for one-pound weights in a pinch.

   If your goal is to get in shape in 1998, you don't have to spend a fortune. You can shed pounds and tone up by selecting the right pieces of equipment and formulating a program of your own. Here are some guidelines for designing an effective workout:

• Always warm up for five to 10 minutes. It's best to perform movements that work the major muscle groups and are similar to those you'll be doing more vigorously later on.
• Perform at least 20 minutes of aerobic exercise. Dancing, stationary cycling, and vigorous walking are just a few examples. Aerobic exercise uses the major muscles of the body continuously over an extended period of time.
• Do resistance training at least twice a week. This can be done in combination with an aerobic workout or separately. Seek balance in your program, working the various muscles of your upper and lower body equally.
• Include flexibility exercises in your workouts. It is best to stretch near the end of your workout when your muscles are warm and most receptive.
• Finish with a five-minute cool-down that allows your heart rate to ease gently back to its resting pace.