How body-age is measured.

Each check is scored against people of the same age and sex, using published norms. A fit 78-year-old is compared to other 78-year-olds, never to a 25-year-old.

• Balance
• Mobility
• Cardio
• Strength
• Sleep
• Nutrition
• Movement
• Stress
• Gait
• Grip
• Falls
• Connection
• Smoking
• Medications

The five highlighted systems (balance, mobility, cardio, strength, gait) also get their own equivalent age in the report, so you can see which system is aging fastest, not just the total.

• Gait speed predicts survival in older adults

  Studenski et al., JAMA (2011)

• Grip strength predicts mortality better than blood pressure

  Leong et al., The Lancet, PURE study (2015)

• 10-second one-leg stance predicts survival in 51–75-year-olds

  Araujo et al., Br J Sports Med (2022)

• Chair-stand performance benchmarks by age and sex

  Bohannon, reference values for the sit-to-stand test (2006)

These are the same functional tests longevity clinics use. We did not invent them. We combined them into one number, because one number is easy to watch change.

1. Every answer becomes an offset in years against a typical peer of the same age and sex. Zero means exactly typical. Plus three means that check looks like someone three years older.
2. “I don’t know” never counts against them. Unknown answers are left out of the math. They only widen the range we show.
3. Checks that medicine would distort are dropped, not guessed. On heart-rate medication, the resting heart-rate check is removed. Counting it would measure the medicine, not the fitness.
4. The offsets are averaged (weighted by how strongly each check predicts health outcomes) and added to their real age. That is the body-age.
5. If too much is unknown, we show a range instead of one number, and below a certain point we refuse to show a confident number at all. We won’t hand you a number we didn’t earn.

The free 5-minute quiz works from what you know and can observe, sometimes from another country. It is a good estimate, and it is honest about its limits.

The live assessment is the real measurement: a coach on a video call takes your parent through the actual tests. Sit-to-stand count. Single-leg stance in seconds. Grip strength. Real numbers, measured the same way every time. The guarantee runs on the live, measured number, never the quiz estimate.

Every month, the same tests, done the same way, live on camera. Family is welcome to watch. The raw numbers (reps, seconds, grip) are always shown next to the body-age, so you never have to take the composite on faith. You can check our math against tests we didn’t invent.

As founding members complete their re-tests, the results go up on our pages, unedited.

Body-age is a motivating frame, not a medical diagnosis. The science of compressing a whole body into one “age” is debated, and we know it. The validated part is underneath: the functional tests themselves, and their published norms.

One more honest note: the physical cut-points (balance, chair-stand, gait) come straight from published research. The scoring of lifestyle checks (sleep, stress, nutrition) uses carefully reasoned defaults, and we recalibrate them as real member data comes in. When the method improves, this page changes with it.

This is an educational estimate of general fitness, not a medical assessment. If your parent has a serious health condition, check with their doctor before starting something new.

If they attend the sessions and their body-age doesn’t come down by 2 or more years in 90 days, you don’t pay.

Start where every family starts: the free 5-minute body-age quiz, or see the 90-Day Challenge.