Q&A: Power Caps Versus Power Targets in Racing

Dear Kevin,
In your response to Guillaume’s IMLanza race plan you said something I’ve heard you say many times, both to me and to other athletes:

never set a target (I’m going to ride 220 watts on the flats…), you should set caps (I won’t go above 220 watts) .

I was wondering if you could clarify to me how this works in practice.  If Guillaume doesn’t have a target wattage, how does he decide how fast to ride on the flats?  Wouldn’t he just push up to his cap of 220 watts and hold it there?  But then that starts to sound like a target, not a cap. Put another way: under what circumstances should Guillaume ride at less than 220 watts on the flats?Thanks for clarifying,
A: Even with a power meter (or heart rate monitor) you’re only looking at your screen / power every so often– mostly you are riding by feel and glancing at your power to see what you are actually producing.  On the flats you’re riding at your idea of “this is how hard riding on the flats should feel early in an Ironman, considering that I have 4 more hours of cycling + a marathon left to do”  On the hills you’re riding at “this is comfortable & sustainable and won’t “burn a match”– if I pushed a little harder it would be too hard).   You’re also asking yourself constantly- “can I really maintain this effort for the whole ride realistically and feel good like running a marathon at the end?”
Caps: If you are riding at what feels correct and you glance down and find that your wattage is too high, then you go easier until you are under your cap.  You’re riding along happily at 230 watts early in the ride, but you have a 220 cap.  When you glance down and see you’ve been doing 230, you ease off and go below 220.
Not a Target: If you are riding at what feels correct / sustainable, but you glance down at see that you’ve been riding at 210 watts and your cap is 220 watts, then you DO NOT push harder (into what feels like an iffy intensity level) up to 220.  Stay at 210 watts.  You might find that eventually you start feeling better and you start riding closer to 220 watts.  Or, it’s just not your day on the bike and you’re only going to feel good at 210 watts.   You might end up having your best run, partially because the fact that you had an “off day” on the bike resulted in fresh legs.  The thing to avoid is to try to push at the power you “should be riding at” even when it feels a bit too hard.
I’m just a beginner– I don’t trust my sense of feel.  If you don’t trust your sense of feel to rein you in then you need CONSERVATIVE power caps (or HR caps), unless you are willing to accept a relatively high chance of catastrophic failure.  Hopefully you’ve had a successful rehearsal workout so you have a reference as to what is in the ballpark of being a decent effort / feel.  If you’ve had a failed rehearsal, you at least know some things NOT to do.
What If I’m Having an Amazing Day?  OK– it’s very rare, but possible, that you are having the day of your life.  For one thing, you can’t tell this until LATE in the ride– feeling unstoppable in hours 1-3 of the bike ride is normal.  I find that the freshness of the taper is good for 2-3 hours of great riding until reality comes crashing down (SOMETIMES HARD).  So… if you feel amazing 2/3 the way into the bike ride you can exceed your power caps only as long as it feels easy– don’t “push hard” to exceed your caps.  Just stop holding yourself back every time you bump against them.  Or you can stay under your caps and be content to feel amazing as you are starting the marathon.
Monitoring Your Power- “Lap Power.”  Finally, the way I track my power on the bike is to look at 3 second power (jumpy) for “what I’m doing now” and “lap power” for “what I’ve been doing since the last time I hit the lap button.”  I hit the lap button often so I can see what I’ve been doing lately:
  • if I’m on a flat section and I see I’m doing 230 lap power but I wanted to do 220, I’ll hit lap and try to keep the new “lap power” under 220.
  • I hit lap when starting a climb to make sure I’m staying under my power cap
  • after I descend and start a new flat or climb I’ll hit lap again
  • if I’ve been riding flat for awhile I’ll just randomly hit lap so that the data I’m seeing is reflective of my recent effort.

About Coady

Lucky to be coaching some really awesome & fun people!
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2 Responses to Q&A: Power Caps Versus Power Targets in Racing

  1. Curtis says:

    Thanks for this response, Kevin. It sounds like what you are saying is that, no matter how much data I have, I should pace my race primarily on perceived exertion and then check it against my cap, rather than pacing my race on data and checking it against perceived exertion. Thinking of a “target” wattage puts data before perceived exertion; thinking of a wattage “cap” puts perceived exertion before data. A “target” tends to set up the (dangerous) mindset of “if I ride below this level I may fall short of my potential”; a “cap” sets up the (preferable) mindset “if I ride above (or even close to) this level I risk fading/bonking/blowing up.”

    This change of mindset has two implications, as I see it:

    – Triathletes love data, and power meters, HRMs, and Garmins give us plenty of it, but this is ultimately secondary to perceived exertion. You’ve probably told me this before but I’m only now “getting it.”

    – Recognizing the priority of perceived exertion over data really underlines the importance of taking the race rehearsals seriously because if I don’t have a solid sense of perceived exertion, no amount of data will save me from myself.

    I’d love to hear any further comments you have. Thanks as always for your advice.

    • Coady says:

      Hi Curtis,

      I’d say that you can trust perceived exertion when it says you should go a bit easier than you’d expect, but you can’t trust it (at least early in the bike leg) when it indicates you’re going too easy even at a relatively high power / HR for you.

      Another way to look at it is that you watch heart rate, power and perceived exertion & objectively decide what to do given all 3 variables. For someone who has very little margin of error or who doesn’t have enough experience / objectivity to make a good decision by weighing all 3 (most ironman racers) you should defer to whichever tells you to go easiest, especially in the first half of the bike. (E.g. even if you feel good at the power you expect to be putting out, if your HR is too high then slow down).

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