QUESTION: Do "toning tables" really work to get rid of fat and help you get fit? I have been told that all you need to do is lie there and the movement of the table will take off inches and help you lose weight. It seems to be too good to be true. Please answer soon so that I can decide whether to buy one of these tables or not. Thank you.

ANSWER: Sometimes things that seem to be too good to be true are too good to be true. This is certainly the case with toning tables (motorized exercise beds that vibrate certain areas of the body).In a study reported in the March/April 1991 issue of In Health magazine, researchers from the University of Florida studied the effect of these motorized tables. These researchers recruited 43 sedentary postmenopausal women of similar size and weight for a supervised exercise program. Twice a week, 15 of the volunteers used toning tables for an hour, and 14 pedaled stationary bicycles for up to 30 minutes. The remaining women did no exercise at all.

After three months, during which all of the participants stuck to their usual diets, the women using the toning tables had trimmed neither fat nor inches, and actually lost some of their aerobic fitness. The cyclists, on the other hand, dropped an average of 21/2 pounds and improved their aerobic fitness. The non-exercisers, as might be expected, made no change in either fitness or fatness.

The reason that the women actually lost fitness on the toning table probably relates to a feeling that they were getting a good workout, so they became more sedentary - and therefore less fit - outside of the gym. The reason they didn't lose weight is related to the reason they didn't get fit; passive exercise is not effective for burning fat in the metabolic pathways of the body. They didn't lose fat in specific areas of the body because spot reduction techniques just don't work. Fat is released from the fat cells during exercise only when the body does the work, not from some outside manipulation over an area of body fat. Further, fat is released from different fat areas based on a genetic pattern that you cannot control. Thus, some women lose fat from the face first, the bust second, and then the hips, and others have another fat loss pattern.THIS WEEK'S HEALTHFUL LIFESTYLE GOALS

- Exercise. This week, I'd like to have you begin doing the "pelvic roll," an exercise suggested by my colleague, Dr. Rulon Francis, as the best prophylactic exercise known for preventing back pain. To feel the movement properly, stand against a wall with your hand at the small of your back to feel the movement of your pelvis. Now, contract your buttocks and abdomen so that the pelvis tilts back and flattens your lower back against your hand. Hold this position for 10 seconds, relax, and repeat about 10 times a day. Once you feel the proper movement, you can remove your hand from the small of your back.

- Diet. Barbara Higa suggests that you now decrease the amount of salt in your diet by one-half.