First it was pace per kilometer and heart rate. Then came heart rate variability, acute and chronic training load… and now, if you look at your GPS watch or the latest launch from your favorite brand, there is one metric that keeps popping up: running power.
In 2025, more and more watches (Garmin, Polar, COROS, Apple Watch), power meters like Stryd and advanced apps are pushing power-based training for runners from the world of cycling into everyday running. The promise is simple: measure your real effort in watts, regardless of the terrain, so you can run more evenly, manage hills better and avoid blowing up in the final kilometers.
This guide will walk you through, in clear and practical terms, what running power is, what current science says, how to set your power zones and how to bring this metric into your training if you have only used pace and heart rate until now.
What running power is and why it can change your training
Running power is an estimate, in watts (W), of the work your body is doing on every stride. In other words, how much energy you are spending to maintain a given speed under specific conditions (incline, wind, surface, etc.).
If pace tells you “how fast you are moving” and heart rate tells you “how your body is reacting” (a consequence of your effort), power tries to measure that mechanical effort directly. That is why many coaches describe running power as “real-time effort” condensed into a single number.
- You run uphill at the same pace as on the flat → your watts clearly go up.
- You run downhill at the same perceived effort → your pace improves, but watts stay similar.
- The wind changes: with a headwind, your watts climb to hold the same pace; with a tailwind, you can run just as fast with fewer watts.
This ability to reflect terrain and environmental conditions is what makes power-based training so useful on hilly routes, trail runs or marathons with constant profile changes.
How running power is measured today (2025)
There is no single universal “running power meter”. Each manufacturer uses its own models and sensors, but for most runners the key is consistency: having a system that is stable and repeatable for you.
1. Dedicated power meters: Stryd and similar devices
Stryd was the first running power meter to go mainstream. It is a footpod that clips onto your laces and uses accelerometers, gyroscopes and physical models to estimate your watts. Stryd calculates your Critical Power (CP), builds a power duration curve and provides power zones (Z1–Z5) to structure your training.
The big advantage is accuracy and stability between sessions, regardless of which watch you wear, which is highly valued by marathon and ultra runners who train with watts all year long.
2. Garmin, Polar and COROS watches: wrist-based running power
Brands like Garmin, Polar and COROS offer wrist-based running power on many of their watches. Some models need an additional pod or HR strap; the latest ones can estimate power directly from the wrist sensors.
- Garmin Running Power: available on many Forerunner and Fenix models, it integrates with Garmin’s widgets, data fields and advanced metrics.
- Polar and COROS: both have embraced wrist-based running power, combining GPS, accelerometers and proprietary algorithms.
The upside is that you do not need extra hardware and everything stays on your wrist. The downside is that measurements can be slightly more sensitive to arm swing and GPS conditions, although for most runners they are more than good enough.
3. Apple Watch: built-in running power in watchOS
Since watchOS 9, the Apple Watch includes native running power in the Workout app. You can add data fields for instant, lap and average power and see the metric both on the watch and in the Fitness app on your iPhone.
If you already own an Apple Watch, this means you can start training with power without buying extra devices. Combined with route and analysis apps, it becomes a powerful tool to control your effort on hills and intervals.
4. Apps and hybrid solutions
Beyond hardware, some apps estimate running power from GPS and elevation data. They are not as precise as a dedicated power meter, but they can be a low-friction way to test the metric before investing in more gear.
What science currently says about running power
Research on running power has grown rapidly, but it is still a younger field compared to decades of work on heart rate and VO2. Even so, several consistent findings can help everyday runners:
- Good relationship with energy cost: multiple studies have shown a strong link between running power and oxygen consumption or energy expenditure across different slopes, which makes it a solid intensity marker, especially uphill and downhill.
- Useful to model endurance performance: models based on Critical Power and the power–time curve can estimate your ability to sustain long efforts (30–60 minutes) and help you set more realistic race targets.
- A bridge between physiology and perceived effort: working close to your CP typically corresponds to intensities near lactate threshold or maximal steady state, so power can complement heart rate very well in key workouts.
One key caveat: there is still no absolute consensus on the “best” way to measure running power or on perfect equivalences with classic thresholds. That is why you should treat power as an extra layer of context for your sensations, not as an infallible lab value.
Critical Power and power zones: the core of power-based training
If you want to go beyond “just looking at watts”, you need two core concepts:
- Critical Power (CP): put simply, the highest power you can sustain for a prolonged effort (around 30–40 minutes) without fatigue ramping up too quickly. It closely resembles your threshold intensity.
- Power zones: wattage ranges based on your CP that you use to structure your training (recovery, easy runs, tempo, intervals, etc.).
How to estimate your Critical Power in practice
Dedicated platforms (Stryd, TrainingPeaks and others) calculate CP automatically from your recent best efforts. If you want a manual estimate without relying entirely on algorithms, here is a simple field protocol:
- Pick a relatively fresh week without too much training load.
- Do two tests on separate days, on flat and similar terrain:
- Test 1: 9–12 minutes at “hard but controlled” effort, as if racing a short event.
- Test 2: 20–30 minutes hard but sustainable, similar to a 5K–10K time trial depending on your level.
- Record the average power for each test (mean watts over the main interval).
- Use an online Critical Power calculator (for example from Stryd or TrainingPeaks) or your watch’s function to derive your CP from those two efforts.
It is not lab-grade, but it is more than accurate enough to structure your power-based training without overcomplicating things.
Typical power zones for runners and how to use them
Each platform defines its exact ranges, but a classic five-zone power model could look like this:
- Z1 – Recovery (below 80% of CP): very easy jogs and active recovery days.
- Z2 – Easy endurance (80–90% of CP): aerobic base work, where you should spend a large share of your weekly mileage.
- Z3 – Tempo (90–100% of CP): controlled but demanding efforts, useful for half and full marathon preparation.
- Z4 – Threshold (100–110% of CP): 5–15 minute intervals close to your sustainable limit.
- Z5 – VO2max (>110% of CP): short, intense reps (30 seconds to 3 minutes) to push your maximal capacity.
Once you have these zones, you can shift from asking “what pace should I run this workout at?” to “which power zone do I need today?” depending on the goal of the session.
A 4-week plan to introduce running power if you have only used pace so far
If you have never trained with watts before, it makes no sense to overhaul everything overnight. Here is a 4-week progression to integrate running power into your day-to-day training.
Week 1 – Observe without changing anything
- Keep your usual training structure, but enable running power on your watch.
- Take mental notes of the watts you see during:
- Easy runs.
- Pickups and strides.
- Long hills.
- Start connecting perceived effort, pace and watts.
Week 2 – Define your CP and your first zones
- Run the two field tests described above to estimate your Critical Power.
- Set up your power zones on your watch or app.
- Do 1–2 easy runs aiming to stay in Z2 without paying much attention to pace.
Week 3 – First structured power-based sessions
- Add one tempo workout, for example:
- 15′ warm-up in Z1–Z2.
- 3 × 8′ in Z3 with 3′ easy between blocks.
- 10′ cool down in Z1.
- Include at least one hilly run where the goal is to keep watts consistent even as pace fluctuates.
Week 4 – Combine power with pace and heart rate
- Add one short-interval session in Z4–Z5 (for example 10 × 1′ hard / 1′ easy) guided by power.
- On a long run, set a target power range (for example, high Z2) and watch how heart rate behaves over time.
- At the end of the week, review:
- Which power zone you spend most of your mileage in.
- Whether your sensations match what your watch is telling you.
The goal is not to become a “slave to watts”, but to use power as an extra tool to understand your body better – especially on rolling routes and on days when pace alone does not tell the full story.
Common mistakes when training with power (and how to avoid them)
- Comparing your watts to someone else’s: running power is highly individual. What matters is your numbers and how they evolve, not your friend’s data.
- Ignoring context: power does not replace your own perception or basic training logic. On a day with heat, poor sleep or high stress, your body may say “no” even if the watts look “perfect”.
- Expecting lab precision on the trail: no system is flawless. The key is whether your device is internally consistent for you from one run to the next.
- Only using power for interval sessions: running power really shines on long, hilly runs and in pacing races, not only in “sexy workouts”.
- Neglecting strength and technique: you can own the best power meter on the market, but if your technique is poor or you skip strength, your running economy will still be limited.
Where SnapRace fits if you train with power
If you run with an Apple Watch or iPhone, you can combine your power data with how you plan and follow your routes. Tools like SnapRace can help you:
- Pick routes with the right elevation profile for each session (for example, an easy Z2 run on gentle terrain or a long run with extended climbs in Z3).
- Get turn-by-turn guidance so you do not need to stare at the map while focusing on holding your target watts.
- Keep a cloud-based history of your runs and see how your pace on a given route changes over time as you train with power intelligently.
The blend of smart routes + power-based training is especially valuable if you live in a hilly city or travel frequently and want your perceived effort to remain consistent even when the terrain changes.
In short, running power is not here to replace everything you already know, but to give you an extra layer of insight to make better decisions. If you introduce it gradually, combine it with strength, technique and proper recovery, and use it to understand yourself instead of stressing over every data point, it can become one of the most interesting upgrades to your training in 2025.