Running power is not cycling FTP
Running power, popularised by the Stryd foot pod, estimates the mechanical power of running in watts. It is anchored to your running Critical Power, not to cycling FTP, and the two numbers are not interchangeable. Running power includes the cost of vertical oscillation, ground-contact dynamics and form, not just forward propulsion, so a runner's watts and a cyclist's watts describe different things.
A typical recreational runner shows a running CP in the low-to-mid 200-watt range, while strong runners exceed 300 W; like cycling FTP, the figure is only meaningful relative to body weight. Never copy a cycling FTP into a running calculator or vice versa.
The Stryd five-zone model
Stryd splits running power into five zones anchored to running CP. Easy (Z1) is below 80% CP, Moderate (Z2) is 80–90%, Threshold (Z3) is 90–100%, topping out right at CP, Interval (Z4) is 100–115%, and Repetition (Z5) is everything above 115%. At a CP of 280 W, Threshold reaches up to 280 W and Repetition is the open-ended band above about 322 W.
The structure mirrors familiar pace and heart-rate zone systems: most volume sits in the easy and moderate bands, threshold work develops sustainable speed, and the top two zones are reserved for short VO₂max intervals and neuromuscular reps.
Why power beats pace on hills
On flat ground pace and power track closely, but the moment the terrain tilts they diverge. Climbing a hill, your pace plummets even though your effort rises; descending, pace flatters you. Running power reacts instantly to gradient and headwind where pace lags, so it reflects true mechanical effort regardless of the profile.
This makes running power especially useful on undulating and trail courses, and for triathletes off the bike. Holding an even power on a hilly route delivers genuinely even effort, which is the most reliable way to pace a hard long run or a race without blowing up on the first climb.
Worked example
For a runner with a running Critical Power of 280 W:
| Zone 1, Easy (below 80%) | ≤ 224 W |
| Zone 2, Moderate (80–90%) | 224–252 W |
| Zone 3, Threshold (90–100%) | 252–280 W |
| Zone 4, Interval (100–115%) | 280–322 W |
| Zone 5, Repetition (above 115%) | ≥ 322 W |
Threshold tops out exactly at CP (280 W); Repetition is open-ended above roughly 322 W.
Frequently asked questions
Is running power the same as cycling power?
No. Both are measured in watts, but they are not interchangeable. Cycling power is propulsion at the cranks, while running power also captures vertical oscillation and form. A 280-watt running effort and a 280-watt bike effort represent completely different physiological loads, so each needs its own sport-specific anchor.
What anchors running power zones?
Stryd's five running power zones anchor to your running Critical Power (CP), the highest power you can sustain for a prolonged period. Threshold (Zone 3) runs from 90% to 100% of CP, so it tops out exactly at your CP. Everything above CP draws on finite anaerobic capacity.
Why use power instead of pace for running?
Pace is distorted by hills, wind and soft ground, dropping on climbs even as effort rises. Running power reacts instantly to gradient and headwind where pace lags, so it reflects true mechanical effort. Holding even power on an undulating course delivers genuinely even effort and smarter pacing.
How do I find my running critical power?
Stryd estimates running CP automatically from your hard runs and races, displaying it in the app, or you can run a structured CP test of two maximal efforts of different durations. Re-check it every few weeks during focused training, since CP rises with fitness and falls with detraining.
Is running power good for trail and ultra running?
Yes. On steep, variable terrain where pace is meaningless, running power gives a consistent effort target across climbs and descents. Trail and ultra runners use it to ration effort over big vertical gain, avoiding the common mistake of surging the early climbs and fading late.
Sources
- Stryd, Running Power & the Critical Power model. Stryd's running power meter and CP-anchored five-zone running power framework.
- Monod & Scherrer (1965). “The work capacity of a synergic muscular group.” Ergonomics 8(3):329–338, the critical-power / W′ two-parameter model.
- Jones et al. (2010). Critical-power framework underpinning running CP and severe-intensity work above CP.