It’s a little after four in the morning in downtown Miami, and silence descends upon the American Airlines Arena. Biscayne Boulevard is empty, and no boats are navigating the bay in front of the arena. Jimmy Butler emerges from behind a black Ford Expedition, swinging a portable Bose speaker and blasting Florida Georgia Line’s twangy tunes. The four-time NBA All-Star is a small-town Texas lad at heart, and he’s in his element on this beat.

Right now, Butler needs to be playing at his best. He hasn’t even unpacked since arriving in Miami, but he needs to return to his work. He’s walking confidently with his performance coach, James Scott, across the parking lot to a practice facility. Days off are not an option if Butler is going to be the focal point of the Miami Heat after Dwyane Wade. Or, mornings off, as the case may be.

In the new era of NBA fitness, this is how you succeed: You begin working hours prior to the likes of LeBron even getting out of bed. Ten years ago, basketball was all about muscle and tenacity (remember Ben Wallace? ), but now, more than any other league, the NBA seems fixated on diet, recovery, and the science of human performance.

Jimmy Butler’s Day Is Dedicated to Exercise

Butler is at the vanguard of this movement, starting his workout at 4:00 a.m. and dedicating the entire day to being fully prepared for basketball. “I don’t skip any of it; it’s a rhythm and a routine,” he states. “I follow the entire process through to the end.” The workout is scheduled to start every hour, followed by agility training, cryo-chamber rest, and court time. While his body is at rest, his mind stays active, reviewing game film and refining his strategic thinking skills through games like dominoes.

Even slumber is rigidly scheduled. Butler aims for nine hours of sleep, which entails going to bed by 7:00 p.m. He uses a cold-air diffuser, herbal tea, and a screen ban to get ready for bed three hours early. “I eat at the appropriate time. Butler claims, “I go to sleep when I’m supposed to.” “I play dominoes when I should be doing something else.”

Over the past two years, Butler’s whole workout regimen has been managed by Scott, a former employee of the Houston Rockets. After 15 years of training NBA players, he has never encountered one quite like Butler. “I had never trained someone at 4:00 a.m. until I started working with Jimmy,” he says. “And regardless of the time or location, he is never even a minute late.”

To strengthen his wrists, Butler begins his routine by shooting a ten-pound medicine ball. Next, he holds 45-pound plates at his sides, lowers them, and rapidly catches them to test his grip strength. Next, he moves on to one of his favorite drills, a mental and balance-attacking game: He gets pulled off-center by a resistance band while standing on one leg while Scott throws him blue and red balls. He needs to use his left hand to catch the red ones and his right to catch the blue ones. He exclaims, “I love this—anything single-leg I like.” “Single-leg box jumps, single-leg squats, and single-leg balance.”

After planks, bridges, and other ab exercises, Butler takes the court. He makes roughly 1,000 jump shots in the following hour, honing a shooting technique that has made him one of the league’s most lethal scorers when it matters most. By the time the first light beams reach the sky, he is on his way home for a recuperation period in the ice or perhaps yoga, followed by more exercises. For breakfast, he is having egg-white omelets, avocados, berries, and black coffee.

At 3:00 p.m., he goes back to the American Airlines Arena to see if anyone is interested in playing pickup. “It’s another level of intensity,” remarks Scott.