Bryan Johnson has spent years trying to convince the world that aging is optional. Now he is trying to convince his own knees, ankles and fast-twitch fibers of the same thing, by teaching himself to dunk a basketball at 49.
The tech entrepreneur turned longevity evangelist introduced the project in a video announcing the first episode of a series he calls “Can Unc Dunk.” At the time he was 48. “I am 48 years old, and I am training to dunk a basketball. The problem is, I’ve never dunked in my entire life. And at my age, the risk of injury is five times higher. So for the next few months, I’m training like an elite athlete to see if I can defy the odds,” he said.
He was candid about the deficit he was starting from. “Well, the bad news is I have little fast switch muscle, stiff tendons, poor coordination, and slow force development,” he admitted, before outlining a plan built around three weekly sessions “designed for athleticism, timing, rhythm, and rate of force.”
The numbers behind that plan read more like a biomechanics thesis than a gym routine. At six feet tall and 180 lbs (81.6 kg), Johnson calculated that reaching a roughly 35-inch vertical would require a takeoff velocity of 14.5 feet per second generated in just 0.2 seconds, producing 585 lbs (265.4 kg) of force and 11 kW of peak power.
“It’s a crazy goal, but if I’m going to live forever, I might as well be able to dunk,” he said.
Months later, the training has continued and the milestones have started stacking up. Johnson recently posted about hitting a new personal record of 365 lbs (165.6 kg) for two reps, explaining that the lift was aimed at building his “raw maximal force ceiling” toward that same 14.5 ft/s, 0.2-second, 585-lb (265.4 kg) target.
It is the kind of detail that makes clear this isn’t a casual bucket-list attempt. It’s an engineering problem he happens to be running on his own body.
That body, he keeps reminding people, does not forgive mistakes the way a 20-something’s does. He has been blunt about the danger involved, tweeting that his age puts him “at 5x greater injury risk in dunk training” because the exercises involved are heavy and technically demanding.
“One mistake and it could be over,” he wrote, before describing how he swapped a planned session for something gentler: “this morning I completed 60 min of zone 2 training (heart rate 134 bpm) and 20 min of dry sauna 200 F. These do not create risk of injury.”
Even a caffeine mix-up became a reason to pull back. After a cafe accidentally handed him fully caffeinated coffee instead of decaf, he cancelled a morning dunk session outright, noting that “acute sleep disruption can increase injury risk by 70-130%.”
That caution fits neatly into the exercise philosophy Johnson has been pushing to his followers heading into 2026, one built on balance rather than heroics.
“Look, we all want to be hot and jacked, but heavy lifting is not the only thing that matters,” he said in another video, adding that “the right combination of training can lower your risk of death by up to 42%.”
His formula calls for six weekly sessions split between strength and cardio, including 150 minutes of zone two work, which he describes as “a level of exercise where you can still maintain a normal conversation,” plus 75 minutes of more demanding effort where “talking is difficult.”
He also folds in mobility, flexibility and balance work, arguing that it “will keep your body resilient and injury-free long-term,” and warns against training too close to bedtime since poor timing “can wreck your sleep and recovery.”
His bottom line has nothing to do with basketball at all: “Friends, the most important thing is consistency. Build an exercise habit and then do it every single day. The science is very clear. Being active in whatever way you can is one of the very best things you can do for your health.”
