The Athletic's Jay King reported that Horford sought advice from legendary quarterback Tom Brady and his fitness and nutrition advisor Alex Guerrero on how to stay healthy as he continues to get older. Horford worked with Guerrero through TB12, the injury prevention company he co-founded with Brady.
Guerrero said that Horford, who turned 38 years old on Monday, was focused on "injury prevention and a position-specific workout regimen that would allow him to flourish for years to come" when they started working together in 2015-16
"We talked about, what is your ultimate playing weight based off your position?" Guerrero said. "At your position, what does that entail? Do you need to move? Is it more based on speed or quickness, quickness or power and strength? Once he began to define that for himself and his position, you can make a customizable program for him that's based on what he's looking to achieve."
Horford said he didn't follow Brady's methods identically, but he still found things from TB12 that helped him in his NBA career.
"For me, it was, like, how can I fit that into my lifestyle?" Horford said, adding that his diet was never as strict as Brady's. "How can I take some of this stuff and use it to my benefit?"
Despite his age, Horford has remained an effective player on both ends of the floor and was a key contributor to the Celtics' run to the 2024 NBA Finals, where they will face the Dallas Mavericks. He will be trying to help Boston win its first NBA title since 2008.