“You don’t have to be a psychologist to figure out you feel better when you look your best,” says Dr. Cathy Flanagan, a cognitive therapist and closet jock. As part of a team at NewYork City’s Cornell Medical Center studying depression and distress in people with HIV, Flanagan has observed there’s “no characteristic so fundamental to survival as a sense of personal control. People who exude control in their lives by their appearance and attitude are also likely to have the rest of their lives in order, and others find that extremely attractive.”

Much of what we conventionally think of as beauty is simply visual clues about biological health: Size, symmetry and proportion of our bodies and features; clear eyes, pink gums and strong teeth; pliable skin and shiny hair and nails. On the most primal level, physical appearance is how we prescreen mates from the gene pool. The only real difference between us and lower species is our unrivaled propensity for embellishing on nature.

“Genetics is like a picture frame--what you put in it is up to you,” says Bill Vayo, a program director at Plus One, New York City’s premier medically based fitness clinic. He recommends 20 minutes a day of such cardiovascular work as brisk walking and strength conditioning (weight-lifting or resistance exercises). “There are several good reasons to exercise regularly if you’re HIV positive. You’ve got the potential to maintain or increase muscle mass and boost immune responses; you can reduce stress, improve self-image and increase quantity and quality of life.” Vayo, a former Marine and major hardbody who’s trained both athletes with HIV and the frailest folks recovering from the ravages of AIDS, says the advantages are both physical and psychological: “Improved fitness equals increased independence.”

More to the point, fitness screams health. Everything from the spring in your step to the drape of your jacket speaks volumes about strength and endurance. Even if you weren’t blessed with an ideal hip-to-waist ratio or strapping shoulders, “an added inch around your chest will make your waist look two inches smaller,” Vayo reminds us. Only humans can do that deliberately. But Vayo cautions that the practice by some HIV positive gay men of using steroids simply to pump up (rather than to stop wasting) can cause dangerous immune suppression.

For “the lean individual,” Vayo recommends eliminating that “slum-shouldered, hunched-over” look by training to improve posture and body mechanics. “Standing tall, keeping the rib-cage high and the shoulders back, gives the appearance of radiant health and vitality.”

Serious athletes and people with HIV have something else in common: Complicated diets and disrupted metabolisms. “You have to understand how the quality of what you eat will affect health and appearance,” says Heidi Skolnik, an exercise physiologist and nutritional consultant. “Lack of micronutrients affects the resiliency of cells, their ability to fight the biological stresses of each day. For example, vitamin C is fundamental to collagen formation, essential to repairing skin and gums.”

Besides adequate amounts and proportions of complex carbohydrates, high-quality protein, the right kind of fats, vitamins and minerals, our bodies require all sorts of trace nutrients only found in actual food. “Unless you can’t eat, nutritional supplements are not meal replacements,” Skolnik says. “Also remember that your body is 65% water; even a 1 percent change in body weight from dehydration can alter the way you feel and look. You see it when your lips start chapping.” Cells need plenty of water, and when we’re not getting enough, it shows on the outside by cracked cuticles, brittle hair, flaky skin and sunken eyes.

Biology intersects anthropology when it comes to plumage and behavioral displays. Whether we’re trying to attract a sex partner or just to get some rude clerk to treat us with respect, we’re all fashion victims. How we decorate ourselves transmits all sorts of messages about rank, age and mental acuity. Impressions matter.

Michael Shernoff, a New York psychotherapist and long-term HIV nonprogressor, swears by the magical healing powers of the mirror. “There’s nothing quite like doing a double take becuase you’re surprised by what you see.” Antiviral research could stop cold if we bottled that glow when you glance at your reflection and think, “Damn, I look good!”