Mavericks practice has long ended, yet Dirk Nowitzki remains doubled over on the baseline, sweat dripping off his nose and puddling on the hardwood. The stopwatch starts once again, and the 40-year-old, 7-foot veteran unfurls into, well, his version of a sprint. Casey Smith, Dallas’s longtime head athletic trainer, shouts the passing seconds. Nowitzki lumbers through the exercise. “Look at that old man run!” Mavs center DeAndre Jordan crows. The average NBA player can burst to one end of the floor and back in under 10 seconds. Nowitzki finally crosses the baseline 16 ticks after Smith yelled, “Go!”

The next evening, after Dallas dispatches Houston, Nowitzki leans against the back wall of the Mavericks’ weight room. He’s donning a black, velvet blazer only a 30,000-point scorer—or David Beckham—can pull off. Still five days shy of making his season debut at Phoenix, which will make him the fifth man in NBA history to play 21 seasons, a reporter chides Nowitzki for collapsing onto a training table following that last, plodding sprint. “I was so tired I had to lay down,” he says. “That was actually not for treatment.”

MAHONEY: How Dirk Nowitzki Continues to Give the Mavericks Life

His physio work on the padded surface began nearly two hours before Dallas started practice. One subsequent hour on the court, followed by a post-session three-on-three game with a few teammates and a player-development intern, and those pesky additional sprints later, Nowitzki’s body understandably needed a reprieve. “Mine isn’t that fresh,” he says. Welcome to NBA life in your fourth decade on earth—only 28 40-year-olds in history have played an NBA game—where foam rollers are just as important as pick-and-rolls. Nowitzki is a testament to that, as those laps were part of the final stage of prepping his return to game action. After ankle surgery in April, a tendon grew inflamed somewhere in the doldrums of late August and early September. Although he worked back to running at full speed and regularly scrimmaging, the setback cost Nowitzki another eight weeks. “I basically had to start from scratch,” he says. “All the work I did in the summer, in July, August, September, was for nothing.”

Smith essentially measured every ounce of Nowitzki’s pain. A transplant from Phoenix’s vaunted medical staff, the trainer has been with Dallas for 15 years and knows the franchise player’s body as well as the man himself. Nowitzki’s flexibility remains elite, for example, but “his joints lost mobility over time,” Smith says. The legend’s knees are intact, but his hips, ankles, and big toes have aged poorly. “Things along that kinetic chain have been the biggest things we’ve addressed of late,” Smith says. When Dirty, as most tenured Mavs staffers call Nowitzki, is strengthening any of those three joints, Smith prescribes those exhausting sprints. They’re designed to force him into short bursts of activity with shorter recovery times, similar to the start-and-stop tempo of live game action.

Scott Cunningham/Getty Images

In eight minutes on Sunday night against Sacramento, Nowitzki contributed three points and four rebounds. He kissed a gorgeous, trademark banker off the glass during his six-minute debut the prior contest. Those 14 minutes literally required over five hours of cumulative preparation. “That’s what it takes these days, unfortunately,” Nowitzki says. When Nowitzki arrived at the Mavericks’ facility for summer workouts, he would stretch onto the training table before rookies Luka Doncic and Jalen Brunson even arrived. The youngsters would trickle into the gym and return 90 minutes later, giggling as the veteran persisted in the training room. Smith and the Dallas staff begin that two-hour, pre-workout routine focusing on his mobility or flexibility, digging and prodding fingers and a Hypervolt massage gun into those troublesome joints. The regimen transitions into specific activation exercises, aiming to stabilize Nowitzki’s body’s now-elevated range of motion to where he can generate force within that range of motion. Like stretching a rubber band, to where it can contain a larger mass without ultimately popping. A series of isometric exercises helps initiate that activation, where a trainer will apply pressure against, say the outside of Nowitzki’s left leg, and instruct the giant to force his limb against the applied weight. That bolsters Nowitzki’s balance and change of direction without actually moving his ailing hip.

Thirty minutes in, Nowitzki’s focus shifts entirely to balance work, where Smith relies on the Delos postural proprioceptive system. “What you don’t want to do is be able to balance on one foot, but your trunk is all over the place,” Smith says. For his ankle, the program places Nowitzki balancing atop an electronic rocking board, which creates instability conditions he must navigate on the fly. An hour through the routine, he enters the weight room to build on those mobility exercises, gradually completing lighter weight reps that increase his core temperature. And after the majority of this procedure focuses on Nowitzki’s lower body, the Mavs now address activating the mobility in his shoulders, thoracic spine and lumbar spine, snowballing until he’s on his feet, engaging his entire body against resistance. Only then does the greatest European player in NBA history finally take the court. “There’s a million things that I do before,” Nowitzki says.

His 1998 NBA Draft classmate Vince Carter, the only other active 40-year-old in the league, employs an opposite approach. “I get on the court first and then spend about 45 minutes on the table,” he says. “That’s how I’ve always been.” Throughout Carter’s two decades in the league, the half-man primed his half-amazing by preempting the team’s first bus to arenas and hailing a taxi—Uber didn’t exist until 2009—to hoist jumpers when only the dance team’s dress rehearsal shared the floor. “I like to shoot in peace and quiet,” Carter says. “And then once the entire team gets here, I can sit on the table and take care of everything else and just get myself prepared.”

That preparation now includes a heightened concentration on sleep patterns and a more expansive stretching routine. Unlike Nowitzki, Carter still avoids deep-tissue massages, but the 6’6" swingman’s body is still rippling with muscle his counterpart never rivaled. Carter, though, has also increased his frequency of weight-lifting sessions in hopes of stabilizing his frame. He’s asked if, similar to Dirty, Vinsanity focuses on any particular joints or muscle areas. He smiles. “Yeah, it’s called ‘41,’” says the game’s oldest active player. Only Carter, Nowitzki, Robert Parish, Kevin Willis and Kevin Garnett have logged 21 NBA calendars.

NADKARNI: Veteran Vince Carter Perfects the Art of Aging

Carter joined the Hawks in this twilight season for myriad reasons. Atlanta houses Turner Sports and NBA TV’s vaunted Studio J, bringing perhaps the greatest in-game dunker ever down the street from basketball media’s grandest stage—on which he will assuredly thrive in retirement. Carter and Hawks vice chairman Grant Hill are also Orlando neighbors, golfing daily during the Florida summers. “Someone with his experience, someone who has been a superstar, who has tremendous credibility, who can be in the locker room as a mentor, as another coach, as a valuable resource,” Hill says. “To me you couldn’t put a price tag on that when you have a young team and you’re going through the process of preparing for a future.” They were teammates in Phoenix during the 2010-11 campaign, when Hill and fellow old head Steve Nash introduced “nutrition” and “yoga” into popular NBA lexicon. Hill arrived in Phoenix at 35, playing six more seasons until he eclipsed 40. Nash ultimately retired after his 40th birthday as well.

“We challenged each other not to accept the idea of aging,” Hill says. “We were fighting Father Time together.” Hill purchased his own pair of Normatech recovery boots, lugging the device in a separate suitcase during road trips. “When I’d get to a city I’d put them on myself,” he says. Teams today typically boast several sets for both pre- and postgame locker room sessions. Nash innovated how players spend minutes on the sideline, rather than merely plopping onto Phoenix’s bench. “I laid on the court because sitting down for me, and to this day, is the worst thing,” Nash says. “You automatically slouch, your neck points forward, your shoulders round, your back rounds. It’s called a flexor pattern. Your hip flexors shorten, which yanks on your lower back. Your mid thoracic gets super stretched and tight, your pecs get shortened, and you get tight in the back. It’s just a negative position.

“For me, coming to the bench exhausted and sitting down in that position was only going to set me back, whether it was five or 10 percent, that’s a negative return for getting back on the court. Laying down just let gravity do its thing and allowed my back to stay gravity-neutral in a way and not have that spine just slouching and bending into horrible, fatigued positions. It’s fairly antiquated sitting on a bench, we do it mostly because we’re conditioned to doing it. It would obviously be much better if guys were warming up on the sidelines.”

Garrett Ellwood/Getty Images

Carter has famously adapted to life as a reserve. Aside from 15 starts for the Grizzlies in 2016-17, he has not opened double-digit affairs on the court since the 2011-12 season. “Vince knows his body well and understands where he is after 21 years in the league,” Hawks coach Lloyd Pierce says. “He’s the kind of guy that’s gonna say, ‘Coach, I need one off. I need a night off, I need a day off.’ So until he tells me that, I’m gonna play him as a regular rotation player that we have on our team. Obviously he’s Vince Carter, but I know where he is. It’s obviously not, ‘Play Vince 10 straight minutes.’” Carter does not have any restrictions, but the Hawks usually deploy their sage in four-minute spurts.

Nowitzki has struggled with that particular concept. Following his rookie campaign, he started all but six of 1,424 games over 19 seasons. Rick Carlisle’s offense will still weaponize Nowitzki’s stretchy shooting ability for Dallas’s playoff push, but as of now, the Mavericks have limited their mogul to 10 minutes off the pine. “I’ll find my routine,” Nowitzki says. He’s debated retreating to the bowels of arenas and sprint hallways. He has grown accustomed to endlessly pedaling atop stationary bikes. “Even in my 20s, I was never a guy that could just go 100 miles an hour. Obviously, off the bench, you can’t really afford that,” he says. “Off the bench, you gotta bring heat.”

“If you’re 19 years old, you can roll out of bed and do that,” Smith says. Fifteen years ago, Nowitzki subscribed to that mantra. He would scoff at teammates like Carter—the duo shared Dallas’s locker room from 2011-2014—ride the second bus, arrive at games with 90 minutes on the clock, briefly warm up, quickly soak his blonde curls in the shower, and enter the Mavericks’ starting lineup. It mirrored his offseason, when Nowitzki and his fabled shooting coach Holger Geschwindner would fire jumpers for two hours, only supplemented by light cardio in the evenings. Dallas has long emailed Nowitzki summer cardio regimens, from step machines to track workouts, solely ramping up his activity towards the end of the offseason when he was preparing to join the German national team or the Mavs’ training camp. Nowitzki’s only pliability training came after on-court sessions with his shooting czar, folding his interminable frame and yanking his limbs. “He puts me in like a pretzel. It’s brutal,” Nowitzki says. “You know how the old school, like Jane Fonda used to stretch?”

CROSSOVER STAFF: Ranking the 30 Best NBA Jerseys of All Time

In his later years, Dallas prescribed a higher dose of base-cardio exercise that only elevated his high heart rate to a pace he could maintain for extended periods of time. “It expands its ability to pump volume and do work efficiently,” Smith says. “It keeps the heart and cardiovascular at a good base and also keeps his weight down.” When the calendar featured those international tournaments, his routine would crescendo into higher intensity cardio for shorter durations with longer recovery periods, just like wind sprints at the end of a three-hour, midseason day at Dallas’s practice facility.

The process has certainly taken its toll. It’s difficult to imagine Nowitzki playing another year, despite Doncic infusing new life into the franchise. His delayed start to this season sparked whispers throughout the organization about a 22nd campaign, but Nowitzki described all of this physical preparation as “trying to make one last push.” Carter appears capable of braving 22 years of service for the first time in league history. It’s a threshold those familiar with the athletic marvel believe Carter craves for his resume. “I think he has another year left in him and he should play as long as he can,” Hill says. “What he’s done here is the icing on the cake. And there’s been a lot of icing.”