Does running power measure your effort?
No.
Running power provides numbers that represent your effort.
If it’s not really your effort, aren’t the numbers meaningless?
No.
The numbers are usable as long as they’re repeatable and valid:
🔹 Repeatable? The same effort under the same conditions gives the same number.
🔹 Valid? The numbers correlate (align) with an existing ‘gold standard’.
The Stryd footpod has been independently validated more than 10 times. It produces repeatable numbers that are highly correlated with oxygen consumption – a gold standard for measuring exercise energy consumption (effort).
Wrist-based power included in the latest running watches has not been independently validated (that I’m aware of). However, I ran my own (N=1) study during 2024-2025 comparing wrist-based power from Garmin, Coros and Apple to Stryd and found they produce repeatable numbers that, for most recreational runners, are correlated to the numbers from the Stryd footpod (when measured as a percentage of Threshold Power calculated for each brand).
But the numbers from Garmin are nothing like those from Stryd!
True.
Garmin and Stryd approach running power differently:
⌚ Garmin estimates external mechanical power based on your weight and how you’re moving. Polar watches also appear to use this approach.
👟 Stryd’s algorithm aligns to internal metabolic cost – your effort. Apple, Coros, Suunto and Wahoo watches also appear to use this approach.
The different approaches result in Garmin/Polar power numbers that are roughly 30-35% higher than the other brands.
BUT, even within the two groups there are differences in the numbers. Which means it’s important that you choose one brand and use it consistently, rather than mixing and matching two or more power meter brands – especially when calculating metrics that use numbers from two or more workouts.
If you pick one brand and use it consistently, as long as the numbers are repeatable and valid (as described above), you can successfully train and race using power.
So running power numbers aren’t meaningless?
Far from it.
👉 Running power numbers can be used as a measure of how hard you’re working when you run – your effort.
And once you can measure your effort, that’s when the real magic begins.
For more on:
- studies that have validated Stryd power, see ‘Stryd Power and VO2‘, part of the Palladino article library.
- the 2024-2025 (N=1) study of wrist-based power, see ‘Running with Power – 2G+AW+COROS‘.