Bryan Johnson reveals an easy test you can perform anywhere to determine your biological age.

Longevity Test Introduction: Bryan Johnson introduced a simple one-leg balance test at the Business Insider's Long Play event, which serves as an indicator of biological age and frailty in older adults.

Test Results and Age Correlation: The test suggests that standing on one leg for 0-7 seconds indicates a biological age of 60-80 years, while longer times correlate with younger biological ages.

Research Support: A Mayo Clinic study supports the one-leg balance test as a valid measure of frailty and independence among adults over 50, although it did not include participants under 50.

Cautions on Balance Testing: Experts caution that the balance test is not a complete evaluation of longevity and should be considered alongside other health assessments.