Running Power – 10 Reasons To use It over Pace and HR

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10 Reasons To Use Running Power

I hear ya. Pace is king.

The thing is, I’ve used POWER for bike training for many years now; in more recent years, I’ve used POWER for running too. Yet, like most of you, I initially started maxxing my attention to sporting stats on pace and HR albeit to varying degrees. After a while, I came to know their limitations and they were pretty good metrics to train with, so I was initially VERY sceptical of Running Power both in terms of how it’s calculated and how actionable it was. To cut a 5-year long story short, if I’m running anything longer than 3-minute intervals then I will use power to some degree ie when I’m planning a run, when I’m running and also when I look at my stats afterwards. It mostly works. I’m a convert.

HEADS UP: There are two broad algorithm types for determining RUNNING POWER and there is no accepted ‘correct’ figure, although STRYD has produced whitepapers showing that their product does tie to the metabolic cost calculation method. I don’t know if the running power products measure Watts or Whatevers but, in my experience, STRYD power appears to be a good proxy for effort, it’s actionable.

Before we get onto the Top 10 reasons to use running power, let’s look at the more general areas where running power can help, and if you’re also a cyclist with a power meter you can stop reading now as the benefits of running with power are pretty much identical those from cycling with power. These are the 3 general areas:

  • Preparing for and planning a run – So here we are looking at creating a structured workout or following a 3rd party plan. This is the area where more developments are needed on the sports software platforms.
  • Executing a training run or race – There are a few aspects that can be improved here, generally, you’re good to go with most of the features you have for HR/Pace if they are also available for Running Power.
  • Quantifying and analysing your runs and the insights that can be derived from that – Power is power and so the cycling power tools will mostly work with running power unless they get confused between your running and cycling power values, STRYD‘s Power Center is awesome too.
  1. Run at the correct levels on non-flat ground
  2. Run at the correct levels on surfaces of varying types
  3. Run at the correct levels in wind (STRYD does this, Garmin Running Power partly so, Apple not at all)
  4. More correctly model your short- and long-term abilities based on a Critical Power curve that takes into account your abilities over sprint, threshold and long durations.
  5. Get a PB: As the drafting effect is minimal, your best race time will likely come from an evenly powered effort.
  6. Ego-boosting numbers you can brag about to your mates – “my FTP/CP is higher than yours” or “my w/kg is higher than yours“. (I’d never do this, but apparently, some people do 😉 )
  7. Your training zones will hopefully change for the better. Quantifying and automatically adjusting for this is much easier with the maths behind power than pace. The performance triggers to update power zones are certainly easier to detect and understand than updating HR zones. I use automatically updating power zones for both running (Stryd) and cycling (Garmin).
  8. Understand your training load (1) – quantify the work you have done in each session. Equally, you can use HR but load based on HR can be skewed by, say, temperature or caffeine.
  9. Understand your training load (2) – Understanding the impact of your work on your ability to run fast NOW and in the future AND on the ever-changing balance between CTL/fatigue and ATL/fitness. This one thing can be an eye-opener to explain your good and not-so-good performances. Once you understand when YOU perform best you can plan for it next time around. This is equally as possible with HR or power, much less so with PACE-based training.
  10. More easily quantify and control tapering strategies.

OK, there are more.

  1. Identify plateauing performances (then train differently)
  2. Easily p
  3. Control uphill/downhill variation – for a variety of reasons you will likely want to use slightly more power going uphill. Quantify with NP:Power ratio.
  4. Using a model like Xert MAP or W’ when you are racing, you should be able to understand your anaerobic reserves at any point in a race ie how much juice is left in your physiological tank
  5. Quantify the effects of drafting (albeit minimal, only STRYD)
  6. Running Power is not exclusive. You can use it alongside pace and/or HR. It’s another tool for your training and racing kit bag.

There are some controversial points there, I’m happy to elaborate in the comments.


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14 thoughts on “Running Power – 10 Reasons To use It over Pace and HR

      1. Jeez, I must be old. I didn’t know there was a lol icon.

        there is some weird stuff going on with wordpress/cache where it doesn’t always like SOME special characters

  1. I don’t mind using power as a training tool, as I was using for indoor rower I’d just like to know how to determine the various threshold to workout.

    1. this might help:
      just run for 30 minutes flat out. that’s your rFTP (near enough)

      if you want to model an entire power curve for all duration based on a 5-minutes maximal power and a 2-hour maximal power and interpolate, then it’s possible but beyond my maths (get the free golden cheetah software, the CP tab does it for you)

      I don’t know how these models translate to rowing. i’d imagine it’s pretty similar

  2. In cycling the mechanical work is well
    understood and measuring power with low noise is very doable — although still seems to have a lot of problems. In running measuring the work output to move forward is impossible to capture in the real world. There are different models that don’t agree and have different trade-offs. That’s before you get into different surfaces like tarmac, cobbles, dirt, sand. Gradients over 10% seem like a problem. Things like extreme cambers are not handled.

    I do not think that running power can do a good job of capturing the total energetic cost of movement in the same way that cycling power does for an efficient cyclist. For example the relative cost of holding your body up while cycling is de minimus compare to the power output of your legs in most situations. But for running the cost of stabilizing your body is really significant and “losing form” when fatigued is increasing inability to efficiently control your body.

    It’s a model and it may be useful but it’s not so simple.

    There are a lot of high-level factors of training and race performance:

    – neuromuscular efficiency
    – neuromuscular fatigue
    – the cardiovascular ability to sustain the current or higher intensity
    – the ability to continue to liberate energy efficiently to sustain the current intensity
    – physiological temperature limits
    – blood volume / hydration
    – psychology

    My personal experience is that power uphill, power downhill, and flat power for running are not really comparable because of the difference in muscle group recruitment unless the gradient is very mild.

    Power as a mode for running seems the most useful to me over relatively shorter intervals where cardiac lag makes HR a poor way to judge intensity.

    I was pretty enthusiastic about power but it is not as straightforward a win as promoted at least for me. I have found myself organically leaning more on RPE and HR more than power over the last year or so.

    I think there is a lot of potential in using very high accuracy HR to do real-time DFA alpha-1 during dynamic exercise which has the potential to replace precision lactate threshold analysis during exercise. I have tried this out but it doesn’t work for dynamic running for me with a Polar H10 and the AlphaHRV CIQ data field.

    Again it’s complicated.

    1. lot of points there!
      “I was pretty enthusiastic about power but it is not as straightforward a win as promoted at least for me. ” that’s true for me too but it IS more straightforward, generally, than the alternatives and over longer duration efforts.

  3. I’ve used Stryd for about 3 year now and find power to be very actionable. Critical power calibration can be difficult for less technically-minded runners since you have to do maximal efforts for different lengths of time. However, CP represents a real phenomenon in body chemistry that can help you dial in your effort over hills, wind, and temperature better than heart rate or pace alone.

    1. yes the full ‘calibration’ is a little more involved. but a maximal 30-minute effort is sufficient. ie a 10k race suffices for most people,
      it’s pretty hard to determine a maximal effort without either a) a maximal effort elsewhere or b) a knowledge of what percentage a hard effort was from a maximal

  4. I’m pretty annoyed that I can’t do power based run workouts on my Garmin 965 with Stryd. I know there is a ConnectIQ data field I could use (RunPowerWorkout), but since I’m limited to 2 ConnectIQ data fields, one of which is used by Stryd Zones, and the other which is used by Core body temp, I don’t have any fields left.

  5. Also mixed feelings. As a (former?) cyclist with a penchant for TTs, I love power, gadgets and numbers, so I bought a Black Friday Stryd last year and used it a lot to begin with. Perhaps not coincidentally, my running fitness improved measurably. I enjoyed that interval training now resembled the TrainerRoad workouts I did on my bike in the kitchen, and found it curiously satisfying that my cycling FTP and running CP ended up being roughly the same.

    But it seems that I can no longer pick a workout from the library and upload it to the Stryd Workouts CIQ app. I don’t know whether I had the initial “free” trial membership. I don’t recall activating it, as I always planned to use it without, thinking that this would be possible.

    Compared to the insane range of workouts and features I get with my TrainerRoad sub, Stryd membership looks like poor value. For now I have reverted to pace-based intervals via Garmin Connect for running training, with Stryd essentially providing more accurate cadence/pace than the watch alone. And a nice, rather pointless, number to look at afterwards in Strava (though not Garmin Connect)!

    When I did use the Stryd Workouts CIQ app on my watch, I found it to be pretty good, though it was very hard to stay within range during some intervals. A gust of wind, for example, would cause a power spike and set the alarm off.

    Maybe I am missing something and you can design and follow a workout using Stryd’s power measurement outside of the Stryd ecosystem? I have a Forerunner 245.

  6. Tried it (for a few years). Tried to like it, but it at best I found it a subpar proxy to pace on the roads and useless on the trails. Pace and HR tell me all I need.

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