Go ahead — enjoy the season. relish the feel of those parabolics on the rare occasions when you do manage to lift yourself from the sofa. Make a few tracks with the snowshoes after stuffing yourself into catatonia. Just don’t get so swept away by holiday decadence that you forget the sports you’ll resume come spring. To ignore some crucial maintenance now could be to court injury later — injury, more
often than not, to one of your joints.

Marvelous as they are, these functional junctions of muscle, bone, ligament, tendon, and such are biomechanical accidents waiting to happen, accounting for 60 to 70 percent of athletic injuries, according to trainers. Tending to them, for an athlete, is something like tipping for a smart traveler: A show of consideration along the way keeps things running smoothly. Your joints undergo incredible forces — a 160-pound runner places up to 1,776 pounds of force on his knee with each stride — and they tempt other indignities as well. Poorly balanced muscle groups throw joints out of alignment, leading to inflammation and torn ligaments. Shoddy athletic technique and overuse beget tendinitis. And the inevitable klutzy move can harvest a sprain. What’s worse, a fluke injury can leave a joint permanently loose and interrupt nerve signals to the brain. Once your fitness starts unraveling at the joints, patching it back together becomes an all-encompassing task.

But not all is grim, despite a dusty nugget of sports-club wisdom that says you can’t strengthen joints. It’s true of ligaments, which tie bone to bone, but you can strengthen the muscles surrounding your hinges and bolster the tendons that connect those muscles to bone. To that end, we’ve provided a guide to shoring up your weak links. The joint-specific workouts that follow can easily be tacked onto an existing routine; mix and match to suit your sport. And in case your range of athletic interests leaves you wondering where to start, we’ve ordered the joints according to vulnerability. We’ve made sure to include exercises that work opposing muscle groups — quadriceps and hamstrings, for instance — which are especially important for joints. That way you’ll avoid muscle imbalances that can make all your efforts backfire.

Ankles

The ankle’s lot is not an easy one, what with all that teetering weight above and shifty ground below. Like an empty beer can supporting a great weight, it’ll hold up fine until it’s tweaked ever so slightly. Small wonder that ankle injuries — 85 percent of which are sprains, with most of the rest resulting from overuse — are the most common in sports. It’s a shame, too, says Dr. John C. Cianca, assistant professor of physical medicine and rehabilitation at Baylor College of Medicine: “Protecting the ankle is very simple.”

Begin by working the various muscles of your shin to guard against sprains and overuse injuries. “Many people are strong in the calves and weak in the front, an imbalance that often leads to a tight Achilles tendon,” Cianca explains. “That forces the anterior tibialis [at the front of the shin bone] to work harder, which can cause shinsplints.” Four simple exercises cover the bases: ankle inversion and eversion (twist your foot to either side against the tension of an exercise band), the toe raise (lie on the floor and cock your toes toward your shin, using the band as resistance), and the basic calf raise (with light weights).

Knees

The knee almost equals the ankle in first- to-crumple honors. Knee problems often stem from overuse, and consequently, any muscle imbalances in the knee will haunt you. Burly quads may be the grail of most any self-respecting outdoor athlete, but if you neglect your glutes and hamstrings, the stronger muscles will tug unevenly at the kneecap. The result? The biomechanical efficacy of the joint breaks down, creating pain that might lead you to favor your other leg, which overburdens its muscles and joints and breeds even thornier problems.

Classic leg extensions and leg curls balance each other well, but as concentric exercises they’re only half the story. They shorten muscles to build strength, but to brace your joints under pressure you’ll need muscle-lengthening eccentric work too, says Dr. Richard Simon, orthopedic surgeon and consultant to everything from U.S. Diving to the Red Clay Tennis Championships. “Eccentric strength is meant to slow down the joint and prevent too much motion,” he says. So the ideal leg workout requires you to do exercises in which you propel yourself in a controlled motion, such as the squat, lunge, vertical leap (jump onto a 12-inch-high box and then hop down), and jumping rope.

Shoulders

As the most mobile joint of the body, the shoulder is alarmingly vulnerable. Despite what you may have heard, the much-ballyhooed rotator cuff deserves little of the blame. “The rotator cuff is sort of a victim,” Cianca says. “It’s composed of small muscles in the shoulder joint, and it gets dumped on by muscles that aren’t doing their job.” A stronger cuff wards off dislocated shoulders, but building up the tangle of muscles surrounding your shoulder blade — the rhomboid, trapezius, subscapularis, and serratus anterior, if you’re taking notes — delivers better results. To strengthen those muscles around the shoulder blade, start with the classic push-up. The seated row, lateral arm raise, and military press help, too. But the most streamlined program includes the wall push-up (precisely what it sounds like), internal and external rotation (fold your forearm across or away from your torso while holding a taut band for resistance), and baby rattle (see photo, opposite bottom).

Elbows and Wrists

Elbow and wrist injuries slow down many a climber. Unlike the shoulder, no amount of strength training will protect your forearms in a fall. Nor will working out stop the wrist numbness that cyclists suffer, a result of gripping the handlebars, which compresses both the median (aka carpal tunnel) and ulnar nerves. But you can reduce the chance of an overuse injury here.

With some 26 intertwining elbow and wrist muscles, when one falters, others have to compensate, leading to muscle strain and inflammation of the joints. Tennis elbow, for instance, which can strike climbers as readily as Sampras wannabes, results from overloading muscles in your wrists. “Conveniently,” says athletic trainer Kevin Brown, a consultant to the American Sport Climbing Federation, “the forearm muscles support the wrists and the elbows.” So strengthening those muscles does double good. For your lower arms, combine the hand grip (squeeze a wad of sports putty), wrist curl, dumbbell rotation (twist the weight counterclockwise as you curl it), and triceps press-down (see photos, opposite top).

Hips

“The hip is a great joint because of its deep socket,” says osteopath Dave Jenkinson, team doctor for the U.S. Canoe and Kayak Team. “It’s very muscular and well protected.” Still, as the central link in the kinetic chain between the torso and legs, the hip warrants some attention. Underdeveloped or overtight hip muscles often lead to hamstring injuries, because if they tire, your body calls for backup from above and below. To target hip flexors, extensors, adductors, and abductors, try a regimen of bounding (leaping across a field in 50-yard stretches), hip flexion (see photo, left), and combinations of the adductor and abductor (stand and sweep your straight leg to either side, like a pendulum, against a taut band).

L O G I S T I C S

Adding a joint tune-up to your existing workout should barely cost you ten minutes apiece, two or three times a week. (We’re assuming you’ve already stretched). Focus on your weakest link. Just as when you pony up an extra few bucks for insurance on a rental car, if all goes well you’ll never fully appreciate the value of your forethought.

Ankle. Start with the ankle inversion and eversion: Hold each contraction for ten seconds, and for each set, complete 20 repetitions per leg. Then do 20 reps each of toe raises and calf raises. Two sets of each exercise should suffice.

Knee. Jumping rope for two minutes can serve as a warm-up; add two-minute spurts after each set of other exercises. Do three sets of squats and lunges, 15 reps each. Then do a continuous set of vertical leaps until fatigue sets in.

Shoulder. Do 20 reps each of the push-up, wall push-up, and baby rattle. For internal and external rotations, 15 reps is good. Do two sets of each exercise.

Wrist/elbow. For the hand grip, wrist curl, dumbbell rotation, and triceps press-down, choose weights that will allow you to do two sets of 30 reps apiece.

Hip. To complete a good bounding session, alternate 50 yards of leaping strides with 50 yards of walking, and repeat the sequence four times. Then do two sets of 20 reps of the hip flexion, hip abduction, hip adduction, and diagonal hip abduction.

Matthew Segal, a Los Angeles-based writer, is rehabilitating a knee he sprained snowboarding.

The Knee Farm

Get your fresh-grown cartilage

“Picture a hard-boiled egg with the top scraped off: The exposed yolk is bone, the white is the remaining cartilage,” says cell biologist Ross Tubo. He’s describing the damage done to articular cartilage — that precious layer of rubbery tissue that serves as your knee’s shock absorber — in the event of a bad ski accident or other ugly impact. Painful, yes, but no longer career-ending for athletes, thanks to Carticel, a new procedure in which your own cartilage is reproduced and surgically replanted into your knee.

Given the dubious alternatives of risking disease by freeloading off a cadaver’s cartilage or doing without the cushion altogether and relying on scar tissue, Carticel offers hope to hobbled athletes. Pioneered by two Swedish scientists who sold their research to Genzyme Tissue Repair in 1992, and awarded FDA approval last August, the procedure entails using a crumb-size biopsy of undamaged tissue to spawn healthy cells. “We mix it with a Kool-Aid-like cocktail of amino acids and sugar, and let it reproduce like mad in a plastic flask for three weeks,” cackles Tubo, Genzyme’s cell biology director. Then it’s a matter of open-knee surgery to inject the fledgling cells, followed by a year of rehabilitation. “It’s like plugging a hole with putty,” Tubo says, citing Carticel’s 70 percent success rate. “Only we’re using the real thing.”

The kicker is that to date only a handful of insurance companies will cover the procedure’s $26,000 tab, thanks in part to medical establishment folks such as Dr. Bill Grana, sports-medicine committee chairman for the American Academy of Orthopedic Surgeons. “I don’t object to patients subjecting themselves to it, but it’s going to take a good five to ten years to gauge its success,” he says. “Show me some science that says you’re really healing the joint.”

Taking Up That Slopeside Slack Time

Routines

Fifteen years as a human shock absorber haven’t hindered the health of moguls guru Liz McIntyre, a silver medalist at the 1994 Winter Olympics. She attributes her relatively injury-free career to diligently maintaining warm and limber muscles in her idle time, when cold clamps down on unwitting hamstrings. “A lot of skiers think they can do a few toe touches before their first run and they’re set for the day,” McIntyre says. “What they don’t realize is that between runs the muscles tighten again. Staying flexible is something you work at constantly while on the slopes.” Or wherever your winter pursuits may take you.

McIntyre’s secret is to take the leg muscles through their full range of motion by employing a series of fluid, controlled stretches. After a brief warm-up — skiers can take a few mellow runs — find a level area, take off your skis, snowboard, snowshoes, or whatever, and do ten repetitions of each of the following exercises over ten minutes. They’re deceptively simple, but quite effective. Repeat every so often, depending on how far the mercury has fallen, and odds are you’ll have the same good fortune as McIntyre.

Pendulum swing (hamstrings): Simply stand with your hips and shoulders square and your weight on your left leg. Keeping your foot flexed at a 90-degree angle and your leg straight, slowly raise your leg in front of you to a 45-degree angle, then lower it back to standing position. Raise your leg higher on each successive lift, being careful not to pull the hamstring or lock your knee. Switch legs after a set.

Bent leg swing (quadriceps): Begin in the same position as above, but bend your leg at a 90-degree angle and swing it behind you. Go until you feel tension in your quadriceps; push a little farther with each swing. Do a full set with one leg; then repeat with the other.

The scythe (abductors, adductors): Keeping your knees slightly bent and your pelvis tilted forward to prevent your back from arching, stand with your feet hip-width apart. Now extend your right leg about a foot in front of your body and, keeping the motion slow and steady, move the leg across to the left until you feel resistance. Then swing it to the right to the same point of tension. After a set, switch legs and repeat.

Calf stretch (calves): Standing at arm’s length from a tree and with your feet hip-width apart, place your palms against the tree and lean into it. Bending your left knee slightly, slide your right leg away from the tree, making sure to maintain heel contact with the ground (skiers will want to loosen their boots). When you feel a tug in your calf, hold the position for about 25 seconds; then switch legs and repeat.

The Tuck Jump

Standards

Long gone are the days of cramming for that spur-of-the-moment ski trip by knocking off a few wall sits, where you brace yourself against a wall until your quads catch fire. Credit the tuck jump, a move of extraordinary efficiency. Besides strengthening the hip flexors and honing balance, this number develops explosive power. “It’s an especially good exercise for skiers because it mimics exactly what they do on the slopes,” says Ron Kipp, director of athletic preparation for the U.S. Ski Team.

The tuck jump, which you can slip into your normal strengthening program, is as simple as it sounds. Stand straight, with your feet just a few inches apart and your arms at your sides. Jump up, bringing your knees toward your chest in the spirit of your splashiest cannonball, touch them for a brief instant, and replant your feet on the floor. Start by doing two sets of five, build up to 15 per set, and eventually work up to five sets of 15.

A Positive Impact

Prescriptions

So you’ve swapped your running shoes for swim goggles and a life membership at the pool, thinking that no-impact sports mean no physical wear and tear. Not so fast. Contrary to popular fitness wisdom, such a move might undermine your health down the road. A recent study clinched what a few researchers already guessed: Since bone tissue breaks down and rebuilds itself not unlike muscle tissue, stress from high-impact sports involving running, and load-bearing activities like backpacking and weight-lifting, can actually strengthen bones.

In the broadest study yet of bone density, conducted at Australia’s Edith Cowan University, doctors surveyed 60 female athletes and found that those who had engaged in high-impact sports for 20 years had much stronger bones than those who swam. “This should alert men and women in their twenties and thirties to start now,” says Barbara Drinkwater, a Seattle-based physiologist and one of the country’s leading bone density experts. “A lifetime of running and jumping exercises is crucial to bone strength.”

That doesn’t mean enter a marathon tomorrow. While stronger bones guard against injury, repetitive impact can predispose athletes to stress fractures. So it’s wise to ease into any new high-impact sport. Start off slowly and increase your duration and intensity by no more than 10 percent each week. “If you tend to overdo everything, running 80 miles a week, you’ll have problems,” Drinkwater says. “Run three miles a day and you’ll be fine.”

Juice Up Your Joints