Functional Performance Longevity Score
Test loaded walking capacity instead of treating grip as longevity itself.
- Difficulty
- Moderate
- Time to result
- ~weeks to results
- Steps
- 5
- Confidence
- 98%
The Functional Performance Longevity Score treats grip as only one component of a broader task. The core test is an unbroken 50-meter walking lunge while carrying two kettlebells, with the load expressed as a percentage of body weight. The movement simultaneously challenges proximal lower-body strength, grip, balance, coordination, mobility, and the ability to repeatedly move from a lowered position toward standing. Those capacities relate more directly to fall prevention and independent living than a standalone dynamometer reading or dead hang. The transcript proposes 110% of body weight as an elite benchmark, although individual safety and scaling remain essential. The result is a multidimensional performance score tied to practical survivability rather than a fashionable proxy metric.
Origin
Extracted from Habits & Hustle; Dr. Jonathan Schoeff said he and trainer Jeff Shuty were developing a functional performance longevity score.
Core principles
- 01Grip strength is a surrogate for whole-body strength, not the survival mechanism itself.
- 02Lower-body strength, balance, coordination, and mobility directly affect fall risk.
- 03A useful longevity test should resemble a function required in real life.
- 04Sit-to-stand capacity and loaded walking deserve priority.
- 05Performance should be scored relative to body weight.
How to run it
- 1
Establish Safety and Technique
Confirm pain-free walking-lunge mechanics and the ability to control each step before adding substantial load.
Pro tip Use an unloaded or lightly loaded trial to standardize stride and depth.
Watch out Do not attempt an elite load without adequate preparation and supervision.
- 2
Select Two Kettlebells
Choose equal kettlebells whose combined load permits controlled continuous movement.
Pro tip Record total load and body weight on the same day.
Watch out A load that destroys balance or range of motion invalidates the functional test.
- 3
Complete 50 Meters Unbroken
Perform full walking-lunge steps over 50 meters without setting the kettlebells down. Observe lower-body control, balance, coordination, mobility, and grip.
Pro tip Use the same course and surface for each retest.
Watch out Stop for pain, unsafe instability, or loss of control.
- 4
Calculate Relative Load
Divide the combined kettlebell load by body weight and express the result as a percentage. Use that value to track progress over time.
Pro tip Treat 110% as an advanced aspirational benchmark rather than a universal starting target.
Watch out Do not compare raw load between people of substantially different body sizes.
- 5
Train the Limiting Capacity
Identify whether grip, quadriceps, glutes, hamstrings, mobility, or balance ended the attempt, then train that constraint.
Pro tip Keep sit-to-stand movements central even when grip is the immediate limiter.
Watch out Improving grip alone may leave the more important fall-related weakness unchanged.
In the wild
A 60-year-old can score well on a hand dynamometer but struggles with loaded lunges and rising from a low chair. The coach shifts training toward squats, split squats, carries, and repeated sit-to-stand work, then retests the 50-meter carry lunge at a scaled load.
→ Testing exposes a lower-body independence risk that grip strength alone concealed.
Common mistakes
Treating the Proxy as the Cause
Grip correlates with longevity because it reflects broader strength; stronger hands alone do not necessarily prevent falls or preserve independence.
Ignoring Relative Load
Raw kettlebell weight does not provide a fair comparison without accounting for the participant's body weight.
Sacrificing Control for a Score
Poor balance, abbreviated steps, or repeated pauses undermine the purpose of a functional test.
Is it for you?
Best for
It is best for capable adults and coaches evaluating functional strength for healthy aging.
Not ideal for
It is not ideal for people with acute joint injuries, severe balance impairment, or unsafe loaded-lunge mechanics without professional adaptation.
From the transcript
“Grip strength is a surrogate marker. It is a one way to measure strength.”
“One of the workhorse exercises that we use is a walking kettlebell pharma carry lunge.”
“So we consider elite would be one percent is 110% of your body weight.”
From the episode
Episode 575: Dr. Jonathan Schoeff: Peptides and the Marketing Behind Modern Longevity - Part 2
Dr. Jonathan Schoeff