Simple Balance Test Reveals Your Biological Age

Longevity enthusiast Bryan Johnson shares a quick way to estimate your body's age.

Apr. 15, 2026 at 4:04am by

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A minimalist neon outline of a person balancing on one leg, the lines glowing with vibrant energy against a dark background, conceptually representing the balance test described in the story.A simple balance test can reveal insights about your body's age and fitness level.San Francisco Today

Entrepreneur Bryan Johnson led a balance test at a recent Business Insider event, demonstrating how standing on one leg with eyes closed can provide a rough estimate of your biological age. According to Johnson, standing for 0-7 seconds indicates a body age of 60-80 years old, 7-15 seconds is 40-60 years old, and 15-30 seconds is 20-40 years old. This test is based on the idea that brain atrophy and loss of balance are signs of aging.

Why it matters

The one-leg balance test is a simple way for people to get a sense of their overall health and fitness level, which may not always match their chronological age. While not a complete medical evaluation, the test can highlight areas where someone may need to focus on improving strength, coordination, and balance to maintain independence and reduce fall risk as they get older.

The details

At the Business Insider event, Johnson led the audience in performing the one-leg balance test, timing how long each person could stand on one leg with eyes closed. A 2024 Mayo Clinic study found this test to be a valid measure of frailty, independence, and fall risk in adults over 50. While the Mayo study didn't provide specific age ranges, Johnson offered his own interpretations of the balance times. The Cleveland Clinic cautions that the test is not a complete balance evaluation on its own, but it can provide a quick snapshot of an individual's physical capabilities.

  • The one-leg balance test was demonstrated by Bryan Johnson at the Business Insider 'The Long Play' event in San Francisco on Tuesday, April 15, 2026.
  • A Mayo Clinic study on the one-leg balance test as a measure of frailty was published in 2024.

The players

Bryan Johnson

A 48-year-old entrepreneur who is obsessed with longevity and shared the one-leg balance test as a proxy for biological age at the Business Insider event.

Mayo Clinic

A medical research organization that published a 2024 study finding the one-leg balance test to be a valid measure of frailty, independence, and fall risk in adults over 50.

Cleveland Clinic

A healthcare system that cautions the one-leg balance test is not a complete balance evaluation on its own.

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What they’re saying

“As you age, your brain atrophies, and your ability to maintain your balance goes away. That's why when you get older, if you fall down, it's no good.”

— Bryan Johnson, Longevity Enthusiast

The takeaway

The one-leg balance test provides a quick, simple way for people to get a general sense of their physical capabilities and how they may be aging compared to their chronological age. While not a comprehensive medical evaluation, the test can highlight areas where someone may need to focus on improving strength, coordination, and balance to maintain independence and reduce fall risk as they get older.