Whatever LeBron James is doing to stay physically and mentally strong entering his 22nd NBA season is working—and people are taking note. In a new Netflix docuseries, Starting 5, about the lives of five of the league’s dominant figures through the 2023-24 season, reporters commented that the now 39-year-old, four-time NBA champion is only getting better with age.

“I’m surprised at myself at this point,” James says in the series. “I’m not tired … my dedication to my work I think is a huge part of the reason why I am still able to play at this level.”

In 2016, it was reported that the NBA star spends $1.5 million on his body each year, according to Bill Simmons, who had spoken to a confidant and shared it on his podcast. James addressed the statement directly in the docuseries, neither confirming nor denying the investment.

“I’ve heard this crazy notion about how much money I spend on my body each year. I kind of just chuckle. That is a number that I will not disclose, but, more importantly, I think it’s just the time,” James says, who credits his lengthy professional career to his dedication and the time he spends on his rigorous biohacking routine.

“He is pushing the limits of what a player’s prime is considered,” says NBA reporter Dave McMenamin in the series on how the all-star has become one of very few to make it to GOAT status for the long haul.

What is LeBron James’ biohacking routine?

On game days, James will wake up around 6:30 a.m., cold plunge for 10 to 15 minutes, warm up on the court in the morning, and nap between noon and 2 p.m. Then, James will do a series of activations, including stretching, massaging, and strengthening his core muscles hours before the 7 p.m. tip-off.

James maintains a strict routine even in the off-season. He eats a diet rich in whole, organic foods, and eliminates sugar, fried foods, and highly processed foods (The star does tout a glass of wine post-game, per the series).

Recovery is also a cornerstone for James.

“Off days are vital,” says James’ trainer Mike Mancias. “Off days give us an opportunity to work on the body.”

James swears by cold plunging for muscle recovery and healing. He also does red light therapy to help with muscle and joint pain. He routinely goes into a hyperbaric oxygen chamber, a coffin-like tube as James’ wife describes it in the series, intended to restore oxygen levels in those who have had carbon monoxide poisoning (It’s FDA-approved to treat specified conditions, although many biohackers have incorporated it into their routines to improve immune health and blood flow).

James also does cryotherapy, in which you are exposed to very cold temperatures, sometimes as low as -250 degrees Fahrenheit to release endorphins and reduce oxidative stress (It has not been approved by the FDA to treat any conditions in particular). He also wears the Normatec leg compression system, which his trainer says helps his legs feel recovered and fresh.

But James’ top health hack, according to the star himself, is one that may be most accessible to the masses: Sleep.

“The most important thing is what he gets for free, which is sleep,” says Mancias.

“Sleep is the best recovery you can have,” adds James, who limits screen time and keeps his room cool to facilitate better rest. “It’s basically equivalent to you putting your phone in a charger before you go to bed.”

He admits he doesn’t get perfect sleep each night, but it’s what he prioritizes the most. “If you try to get the most sleep that you can get, that’s the only way that you’re going to get back to 100%,” James says.