—Photo-Illustration by TIME (Source Images: Anastasiia Krivenok—Getty Images, nicomenijes/Getty Images, Alexandr Dubynin—Getty Images)Dr. David Shau is in a plank position on his living room floor, and his toddler is sitting on his back, giggling. This is core training, orthopedic-surgeon style—and it’s one of the milder things Shau, who specializes in hip and knee replacements, does to keep his own body in working order.Ask an orthopedic surgeon—doctors who specialize in the musculoskeletal system, including bones, joints, ligaments, and muscles—what they do to stay healthy, and the answers get strange fast. They do toe yoga at their desks. They hop around like pogo sticks at the bus stop. They brush their teeth in a lunge, stretching the Achilles tendon they know is often first to go. They sit on the floor with their legs crossed and try to stand back up without using their hands. (People who can do this, it’s been shown, have a five-times lower risk of dying in a given time frame than people who can’t.) These aren’t quirks: They’re the byproduct of a job spent watching what happens when people stop maintaining their bodies. The surgeons who rebuild knees, replace hips, and fuse spines for a living have, over decades of practice, developed a set of personal habits that don’t look much like the wellness advice the rest of us hear. Some are surprisingly small, some are weird, and all of them are doable.Here’s what six orthopedic surgeons do to stay strong, mobile, and upright as they age.They prioritize legs over almost everything elseMany people lift weights to look a certain way: toned arms, a flatter stomach, a more defined chest. Dr. Cory Calendine, an orthopedic surgeon in Brentwood, Tenn., trains for something different. “I train legs like my life depends on it,” he says. “And statistically, it does.”The case he makes is straightforward and a little jarring. “The single biggest driver of losing your independence as you age—it’s not your heart or even your memory,” he says. “It’s your legs.” Once you can’t stand from a chair without using your hands, or catch yourself when you stumble, the cascade starts. And by the time most people notice their legs have gotten smaller, the more important loss has already happened. Power—the explosive, fast-twitch capacity that catches you mid-fall—goes first. Then strength. Mass, the thing you can see in the mirror, is the last to go. “Most of us are training for mass,” Calendine says. “But by the time you’ve lost mass, you’ve already lost the power.”That’s why, for Calendine, every Sunday is leg day. He's moved away from heavy barbell squats, which were rough on his lower back, in favor of single-leg work and weight machines. It lets him keep the weights heavy while protecting his spine.They take two self-tests at home to check their longevityCalendine uses two simple tests to track how he’s doing—both free, easy to do in your living room, and surprisingly predictive.The first is the sit-to-stand test, sometimes called the floor test. Cross your legs while standing up and holding your arms out to the side, lower yourself to sit criss-cross on the floor by bending your knees, and stand back up—without using your hands, knees, or any furniture, or losing your balance. A perfect score is 10 out of 10. Every assist—a hand on the floor, a knee on the ground, a push off the couch—costs you a point. The test comes out of a Brazilian study of more than 2,000 adults, which found that people who scored 1 or 2 had a five-to-six-times higher mortality risk than those who scored 8 or above.“The test is a mirror,” Calendine says. “The low score doesn’t kill you, but it’s a signal of the reserve you have left in your body.” In other words, it’s a measurement you can repeat over time to see whether you’re losing ground or holding it. The second test is simpler and safer for anyone who’d find getting up from the floor difficult. Sit in a chair, without using the armrests. Stand up and sit back down five times, as fast as you can. If it takes you longer than 15 seconds, that correlates with roughly three times the standard all-cause mortality risk, Calendine says. He likes both tests because they double as motivation. “Am I using more furniture to stand up than I used to? Is it taking me 14 seconds when it used to take 11?” he says. “It’s not a death sentence. It’s a light on the hill.”They do speed work mid-weekCalandine builds short, explosive speed sessions into his week—not for cardio, but specifically to train the fast-twitch power that fades first. Think jumping in place, hopping side to side, or moving through squats with a slow descent and a fast burst back up. The point is to train your body to generate force quickly, which is what catches you when you stumble.Here’s exactly what Dr. Vonda Wright, an orthopedic surgeon in Orlando, does to maintain and gain speed. Twice a week, she does four sprint intervals of 30 seconds each—going as hard as she can for half a minute, resting, then repeating—on a treadmill, bike, rower, or elliptical, whatever’s at hand. That’s a total of two minutes of movement. “Going as hard as you can for 30 seconds—it’s amazing for your mitochondria, your metabolism, for blood flow,” she says. “And frankly, it makes you feel like a badass.”You don’t need a gym to do this. Shau, an orthopedic surgeon at Texas Health Joint Replacement Surgery Center, gets his speed work in by chasing around his daughter in the yard (when he’s not acting as her personal bench). “She’s running, I’m chasing—she’s having a blast, and I’m getting my cardiovascular,” he says. “Short bursts, high intensity.”They lift heavy, in a specific wayRecreational lifters often do 8 to 12 repetitions of an exercise before resting—a moderate-weight zone that builds muscle but stops short of true strength training. Wright lifts heavier than that on her main movements.“I lift in the four-to-six rep range on my power lifts,” she says. The lower the rep count, the heavier the weight has to be to max you out—which means a 4–6 range demands significantly more load than 8–12. Heavier loads train strength and power more efficiently than lighter ones, and they drive the kind of mechanical stress that builds bone density. Wright says her own bone density scans come back “better than a 30-year-old’s.”The implication, especially for women over 40, is significant. Bone loss accelerates around menopause; heavy lifting is one of the few interventions shown to slow or reverse it. Wright doesn’t lift heavy weights for aesthetic reasons. She thinks of it as osteoporosis prevention with a barbell.They focus on muscle contraction during weightliftingDr. Rahul Shah, an orthopedic spine surgeon at Premier Orthopaedic Associates in New Jersey, lifts weights three to five times a week—but he’s careful to distinguish what he’s doing from what many other gym-goers are doing. “I’m not moving weights,” he says. “I’m making sure that I’m contracting my muscles. Those are two different things.”The weight on the bar actually matters less than the quality of the contraction, he says. Swinging a dumbbell with momentum recruits less muscle and risks more injury than lifting a lighter weight with deliberate, controlled tension. Shah’s advice is to start lighter than you think you need to, focus on full range of motion, and watch for swinging. If your form breaks down or you’re using momentum to move the weight, it’s too heavy.They earn their sleep by working hard during the dayA body that’s genuinely tired sleeps. Shah treats daytime exertion as the precondition for nighttime rest, rather than the opposite.“I find that if I don’t work hard enough, I don’t get enough sleep,” Shah says. “I almost earn the sleep that I get.”For him, that means taking 10,000 to 15,000 steps a day, strength training three to five times a week, and cardio twice a week, with each workout capped at around 80 minutes. They stretch every day—and treat flexibility as the gateway to everything elseOrthopedic surgeons will bend over backwards to defend daily stretching. Wright argues that flexibility is what keeps every other form of exercise possible. “The reason we become 90 years old hunched over and shuffling is because we’ve lost hip range of motion or knee range of motion,” she says. Wright is also a fan of an unusual tool: a 6-foot length of PVC pipe, which she recommends as a cheap home aid for keeping the upper and lower back supple. Hold it across your shoulders and twist; hold it overhead and lean—there are dozens of mobility drills online built around it.Dr. Jason Snibbe, an orthopedic surgeon in Los Angeles who’s a consultant for sports teams including the Clippers and Lakers, sets aside 15 to 20 minutes a day on a yoga mat for child’s pose, glute stretches, hip openers, and hamstring stretches. Shau doesn’t carve out dedicated stretching time—he weaves it into his routine. He stretches his Achilles tendon while brushing his teeth, does calf raises and arm stretches in the shower, and flexes his fingers at stoplights. Between surgeries, he runs through thoracic and lumbar stretches, neck exercises (heavy surgical helmets are punishing on the cervical spine), and wrist and shoulder rotations. “Motion is lotion to your joints,” he says.They train balance and foot speed at their desksWright’s most unusual habits all serve the same purpose: preventing falls. “Seventy percent of hip fractures occur in women,” she says. “And hip fractures are incredibly dangerous in older adults—roughly 20% to 30% of patients die within a year.” That’s why she trains her balance and foot speed daily, including in surprising places.When she’s sitting at her desk, for example, she does quick sessions where she taps her toes as fast as she can. At bus stops, she does “pogos”—hopping in place. “You might get some looks,” she says, “but your health is worth it.” She also works in tree pose and single-leg standing throughout the day, treating balance as something to be practiced in seconds, not sessions.They eat a gram of protein per pound of body weightSnibbe sticks to a strict protein formula: a gram per pound of body weight, every day. “If you weigh 120 pounds, you have to have 120 grams of protein,” he says. “It’s very hard to achieve that.” His staples include eggs, meat, chicken, beans, cottage cheese, and yogurt. Snibbe’s target is higher than the federal dietary guidelines, which recommend roughly 0.5 to 0.7 grams of protein per pound—though many researchers argue that active adults, and older adults at risk of muscle loss, benefit from intakes closer to Snibbe's.Shah keeps his approach simpler: three or four meals a day, three or four main ingredients per meal. A typical breakfast might consist of oats, protein powder, berries, and nuts. The goal is to get enough protein to preserve muscle mass as the body ages, since muscle loss after 30 is the slow leak that drains everything else, he says.They strengthen their core with weighted planksShau is unequivocal about the importance of core strength. “Taking care of your core can really offset a lot of different pains throughout your body,” he says. Most lower-back issues stem from weak abdominal and pelvic muscles. That’s why his daily routine centers on holding a plank for as long as he can with his daughter sitting on his back. The added weight intensifies the contraction, while her cheerful laughter makes it sustainable.For anyone without a willing child, he recommends wall sits as an alternative—backed against a wall in a seated position, ideally at 90 degrees, for as long as you can hold it. Both moves are body-weight exercises that require no equipment and minimal space.They take rest as seriously as trainingIt’s the one habit on this list that’s about not doing something. Dr. Heather Menzer, an orthopedic surgeon at Phoenix Children’s Hospital, makes the case that recovery isn’t the absence of training—it’s part of it. “Tissue happens when you rest, not when you train,” she says. The actual rebuilding that exercise initiates happens during sleep and downtime, which means an under-recovered body never gets the benefit of the work it’s putting in.Menzer pays attention to early warning signs of overtraining: pain that gets progressively worse rather than better, fatigue that doesn’t lift, performance that flatlines. Her advice when those signals appear is to adjust the routine rather than try to “outwork the problem.” They check the soles of their shoes regularlyMenzer’s most unusual habit takes about five seconds: Flip your shoes over and look at the tread. If you can’t see the pattern anymore, it’s time to replace them. “Like a mechanic would say about your tires,” she says—except people usually remember to check their tires.Worn shoes are a sneaky culprit behind foot pain and even pain that might seem unrelated to your feet. Knee, hip, and back pain can all trace back to shoes that have lost their support, she says. It’s part of a broader principle Menzer applies to her own body and her patients: Don’t assume the pain is always coming from where it hurts. The root cause is often somewhere you haven’t looked.