04/23/2026
WE HAVE THE FOUNTAIN OF YOUTH!
This article claims balancing on one leg determines your biological age, with 30 seconds being the best.
... But our yellow belts are required to do it for 300 seconds.
Guess that only means one thing: train kenpo, live forever.
Close your eyes, lift one leg, and start the timer.
Bryan Johnson, the 48-year-old tech entrepreneur who spends around $2 million a year trying to stop aging, stepped onto the stage at Business Insider's The Long Play event in San Francisco on April 15, 2026, and gave the audience something they did not expect.
He asked them to stand on one leg.
The test is simple. You close your eyes, lift one foot, and hold the position as long as you can without grabbing anything or touching your other leg. According to Johnson, if you can only hold it for zero to seven seconds, your body is functioning like someone aged 60 to 80. Seven to 15 seconds puts you in the 40 to 60 range. Holding for 15 to 30 seconds suggests a biological age of 20 to 40.
But then the science behind it started drawing serious attention.
A 2024 Mayo Clinic study of adults over 50 found that among several functional fitness tests, the one-leg balance test was the measure most strongly affected by age. The researchers called it "a valid measure of frailty, independence, and fall status." Separate research has shown that an inability to hold a five-second single-leg stance predicts injurious falls, and that completing a 10-second version is linked to lower all-cause mortality risk.
Johnson explained his reasoning directly. He said that as the brain ages, it atrophies, and the neurological signals required to maintain balance start to degrade. That is why falls become so dangerous in later life. A fall at 70 can be a life-altering event in a way it simply is not at 30.
The Cleveland Clinic has noted that the test alone is not a complete picture of balance or longevity. Johnson himself uses dozens of biomarkers and tracks himself constantly through his Blueprint protocol. His DunedinPACE score sits at 0.69, meaning he is reportedly aging at 69 percent of the normal rate.
What makes this test unusual is that almost anyone can try it in the next 60 seconds
