Evolution Index
Matt Roberts EvolutionWhat is your body capable of?
One score, 0 to 100, from ten measurements, against everyone else your age.
A quick test — try it now
How long can you stand on one leg with your eyes closed?
So we can tell you where that puts you:
Stand within arm’s reach of a wall or a counter.
Choose your age and sex above, then start the clock.
Shoes off if you can, and stand within arm’s reach of a wall or a counter. Eyes closed, hands wherever you like, the raised foot clear of the standing leg. Steady yourself for the first second, then let go — and stop the clock when you touch down or grab hold.
Why eyes closed
The balance test that separates people.
With your eyes open, seven in ten 53-year-olds can stand on one leg for a full thirty seconds, so the test separates almost nobody. Close your eyes and the spread opens: in a national study of English adults aged 50 to 69, the typical time was four to six seconds, and one in ten held it past eleven to nineteen, depending on age and sex.
It is a reference, not a prediction. The study gives percentiles — where you stand against people your age and sex — and no evidence about falls or survival.
It covers ages 50 to 69 and no others. Outside them there is no table to score against, so the result says so rather than inventing one.
It is also one measurement. It says nothing about how hard your heart can work, how much force you can produce, or whether you can get off the floor unaided.
Grgic J and colleagues, GeroScience, 2026, from the English Longitudinal Study of Ageing, 2012–13. The ten-second stand with eyes open stays inside the Index as a floor, on its own evidence: adults aged 51 to 75 who could not hold it died at a higher rate over the following seven years (Araújo and colleagues, British Journal of Sports Medicine, 2022).
The measurement
Ten measurements. One number. Error bars published.
The balance test is one of ten. Together they measure the three things that decide how long you stay useful, and your score on each is your percentile — where you stand against adults your age and sex. Why that matters.
Biological age guesses at what your body is. This measures what it can do.
Your weakest domain sets your band, not your average — a strong heart does not buy you out of a floor you cannot get up from. Every score is published with the error around it, because a change smaller than the measurement error is not a change.
Every measurement you add narrows the range. A grip reading, a DXA scan, a measured VO₂ max — each one makes your number more certain.
Fifty is average, and average means declining at the same rate as everyone else your age. That is ageing on schedule rather than holding your ground, so Holding starts at 55: you have to beat typical to reach it.
Which has a consequence worth saying out loud rather than leaving you to find on your own result. Scoring 50 puts you in Slipping, and roughly six in ten people land in Slipping or Reversing. That is what the population data shows. It is not a fault in the scale.
You also get a Capacity Age: the age at which your measurements would be holding their ground rather than declining. Most people read an age faster than a percentile. Where your result runs past the ages the reference data actually covers, it says so — “30 or younger” — rather than inventing a number.
Measured somewhere else?
Already been measured? Bring it.
A VO₂ max from a sports clinic. A DXA scan. A grip reading from a physio. Most of it is sitting in PDFs doing nothing. The Index is where it adds up to one number — taken anywhere in the world, at any time — and the more you bring, the more certain that number gets.
Each reading is asked how it was taken, because a measurement’s protocol is part of the measurement. One taken in a way the reference figures do not cover — a VO₂ max on a bike, when the figures are for treadmills — is kept and shown but not scored, and the page says which table is missing.
What the number is for
The score is the diagnosis. The programme is the point.
If movement is the domain holding your Index down, no amount of cardio moves it. Most people train what they are already good at, because that is the part that feels like progress.
Twelve weeks, built around the domain holding your Index down. Retested at the end on the same tests, so you can see what moved and by how much.
The retest is included. It is the reason the price holds: a twelve-week plan that cannot tell you whether it worked is a guess with a schedule attached.
The practice
Measured in Mayfair, on calibrated equipment.
The test is free and you run it yourself. The assessed Index is measured by the Evolution team, and the two are not the same thing — a self-measured result carries the wider error of self-measurement, and says so on the page.