Learning to relax is an elusive goal in this era of fast-track living. Instead of enjoying the peace and quiet of commuting time, hotshots install mobile phones in their Volvos. Folks are giving up a precious hour of sleep to do aerobics routines at 5 a.m.

After a whole day of rushing around, it's not easy to shift into neutral. That's why many of us need instruction in the art of relaxation.

One of the best ways to harmonize mind and body is to exercise. But if you can't imagine leaping out of bed before dawn to do pushups, it's not always easy to find time for exercise.

So along comes Raquel Welch to the rescue.

"A Week With Raquel" (HBO Cannon Video, $29.95) features a seven-day workout program of 15-minute daily sessions. The theory behind this truncated program is that few people can fit an hour's workout into their schedules. As Welch says: "A little bit of exercise every day is better than killing yourself once in a while."

That may be so, but it's hard to see how one can get any aerobic benefit from moving around for only 15 minutes. This is barely a warmup time for the muscles. Anyway, most health experts don't recommend an hour every day. They usually suggest 20 minutes to an hour of vigorous exercise three times a week.

But Welch's tape does have a great gimmick. The viewer plays a segment on Monday, switches off the tape and leaves it in the VCR until Tuesday. At the end of the week, the exerciser merely rewinds the tape. (Never mind that most videophiles suggest rewinding tapes after every use to reduce stretching.)

Welch's exercise program is heavily yoga-oriented. It should help harried yuppies learn to stretch.

One note: The true audience for this tape may not be the exercise set. Welch wears some revealing leotards that will titillate the saloon crowd. And her deep-breathing exercises suggest much more than the satisfaction of getting a good lungful of oxygen.

"A Week With Raquel" is available at local video stores or from HBO Cannon Video, 1370 Avenue of the Americas, New York, N.Y. 10019. (212-977-8990.) Rating: (STAR) (STAR)

FACE THE FACE: Another celebrity touting a beauty tape is hardly news in the video world. "The Acupressure Face-lift" (Karl-Lorimar Home Video, $19.95) is a bit different because it bypasses the usual exercise and diet regimen to focus on the ancient Chinese art of acupuncture.

Lindsay Wagner, former star of "The Bionic Woman," demonstrates acupressure (a technique that substitutes finger pressure for needles) designed to increase circulation to the face. While the technique won't acheive the same effect as an actual face-lift, it is supposed to improve the health of facial skin.

Whether the technique works or not, it certainly is relaxing. Wagner, a calming hostess, leads the viewer in a massage session while Chinese-inspired, new-age music plays in the background. Although the tape is only 20 minutes long, it works as a marvelous wind-down for the end of the day.

"The Acupressure Face-lift" is available at local video stores and from Karl-Lorimar, 17942 Cowan, Irvine, Calif. 92714 (714-474-0355). Rating: (STAR) (STAR) (STAR) 1/2

MIND OVER MATTER: The best of the relaxation tapes reviewed this week comes from Potentials Unlimited, a manufacturer of self-help audio tapes. "Subliminal Persuasion Video: Relaxation" (Potentials Unlimited, $49.95) is an audio-video program that uses the power of the mind to undo stressful thoughts.

The audio tape has two sides: The self-hypnosis side is designed for nightly play, and the subliminal side can be used when driving a car, exercising, etc. The videotape can be used whenever a viewer has a spare 20 minutes to plop in front of a TV and gaze at lovely shots of Hawaiian landscapes. Hidden amid the new-age music on the soundtrack are subliminal suggestions for relaxation.

I'm a big believer in the power of hypnosis and subliminal persuasion. I have found other Potentials Unlimited tapes to be profoundly useful. After spending less than the recommended amount of time with the relaxation video, I may not be a more relaxed person yet. But I certainly enjoyed the time I spent being naturally sedated.

Other subliminal video programs include: concentration, creative thinking, enthusiasm, good study habits, memory improvement, money-prosperity, relieving stress and anxiety, self-confidence, stopping smoking, subconscious sales power and weight loss.