What are the most objective ways to measure general human performance?
Hello there! I've been interested in quantifying my performance for a while, and have been thinking about how to design a versatile, general, and objective way to track it over time.
Here's the tension that got me started: things like a 5k time or a powerlifting total are great predictors of performance in their own domain, but they're too specific. Training for a 5k time basically forces you into one training style and one test. And even when we use a 5k time to estimate performance in some other endurance event, it feels like we're just using one race time to guess at another — like there's some underlying "endurance ability" we're actually trying to get at, and the race time is just a proxy for it.
VO2max is the closest thing I've found to that "holy grail": a number that predicts performance across a wide range of novel cardiovascular-dominated challenges, and that can be estimated from all kinds of different workouts rather than one specific test. So my goal became: can I find (or approximate) that same kind of number for other areas of performance?
For now I'm focusing on three areas: peak aerobic capacity, sustainable aerobic output, and strength. There's obviously more to "performance" than this. Flexibility, balance, reaction time, fine motor control. But I'm scoping to these 3 for now. More on that at the end.
1. Peak Aerobic Capacity: VO2max
Nothing revolutionary here. Any fitness tracker can estimate it from a wide range of workouts with reasonably good accuracy, and it's well-proven as a predictor.
2. Sustainable Aerobic Output
This is the effort you can sustain over a longer duration, as opposed to VO2max, which reflects your maximal instantaneous aerobic output. Here I had to get more creative. I'm using power output sustained at the top of your Zone 2 range as the proxy. I use power instead of pace because pace is sport-specific (running pace doesn't transfer to cycling), while power is more generalizable across modalities.
In theory you could get this from one clean steady-state effort at the top of Zone 2. But I wanted to be able to estimate it from a wide range of aerobic workouts, not just one specific test. Which means pulling power-over-time and HR-over-time samples from many different workouts, smoothing them, and interpolating what the power output would be at the top of Zone 2. It's not a perfect signal, but it's workable.
3. Strength
Obviously there's no single unit for "general strength," but I tried to get as close as I reasonably could.
The approach: pick one exercise from each of the main movement patterns. I'm using Hinge, Squat, Horizontal Pull, Vertical Pull, Horizontal Push, and Vertical Push. For example: Romanian Deadlift, Front Squat, Pendlay Row, Pull-up, Bench Press, Overhead Press.
From each lift's heaviest set, estimate a 1RM using a formula like Epley or Brzycki (could just as easily be a 5RM-based estimate, the point is standardizing to one number per lift).
You can't just average those numbers though. A Deadlift will always outweigh an Overhead Press and skew the result. So instead, I use population strength standards (like the tables on strengthlevel.com, no affiliation) to convert each lift into a common "unit." For example, if the average Bench Press for an intermediate lifter at 80kg bodyweight is 98kg, and the average Overhead Press is 62kg, that gives a 1.58x conversion factor to express the OHP as a "Bench Press equivalent." Once every lift is converted into the same unit, I can average them into one general strength number and then divide by bodyweight as the final step.
To be clear, there are a lot of formulas, estimations, and normalizations stacked on top of each other here, and I wouldn't call it precise. But I do think it's a solid predictor of strength across lifts you haven't even tested.
Conclusion
Since there is a lot of math for these I am writing some code to do the calculations for me from my Apple Health data.
What I'd love feedback on is the choice of these 3 metrics specifically, and the way I'm calculating each one. Does this hold up as a general approach, or would you go about any of them differently?