Race pace | 80/20 Endurance

Race pace

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    Me again.

    How would you recommend estimating my race pace for my marathon? I did the marathon simulator 20 miler last weekend at the top end of my Z2 pace. Does this sound about right?

    David Warden

    Dean, it sounds exactly right. See our document Race Pacing and you’ll see that upper Zone 2 is exactly within the range recommended for a Marathon.



    Thanks David. As I say in the other thread, my race has now been cancelled!


    Am I right in thinking you just go off Zone 2 pace for a race and ignore heart rate?

    I did my marathon simulator the other day and kept my pace steady in middle of Zone 2 all the way, but my heart rate went from low Zone 2 to top end of Zone 3.

    It was 22c by the end so i’m guessing this played a part in my heart rate escalating?



    I’ve actually found another marathon to do, so I’m on for 4th October at Dorney Lake. So, I’ve just done the marathon simulator too.

    I did the 16 mile section at the top end of Z2 (about 5 seconds per mile from the very top end) and found it reasonably comfortable. I’m hoping that, given the taper in the final two weeks, I’ll be able to keep that up for the 26 mile total.

    I have noticed that the TrainingPeaks 80/20 level 2 plan allows the meat of the long run to be done in Zone X if desired. I don’t normally go much beyond the top of Z2 for those runs, but I’m expecting that my HR will drift into Zone X for the marathon, even if most of it is run at top end Z2 pace.

    Where’s your marathon Paddy?

    David Warden

    @Paddy Your pacing plan on race day should be the same as your pacing plan in training. If you use HR in training, use it in racing. And, of course you’ll use what you learned in training and apply it to racing. In your case, you learned that you experience cardiac drift (which is normal) in your long runs, and that HR and Pace start to become uncoupled. This will allow you to make the decision to maintain a certain pace even when HR drifts upwards, because you know it worked in training. Since you also used Pace in your training, I’d rely on Pace as a primary and HR as a secondary. It’s still a good idea to set an upper limit on HR for a marathon, say upper Zone X or Zone 3, even with normal cardiac drift.

    The temperature also absolutely played a part in your elevated HR. This is another normal development using HR in increasing temperatures.

    @Dean You’ll notice that not only do the long marathon plan runs give you “permission” to go into Zone X, our Race Pacing guide provides the same range for a marathon. It’s a matter of risk/reward and experience level to decide to wade into Zone X, and should certainly be tested in training first. If your 16-mile run was done in Zone 2, I’d stick there, but a small drift into Zone X after a taper is a limited risk.



    Thanks David.

    This is my first 80/20 marathon, so I’ll be taking it at top-end Z2 pace and see how I go into the final 10k. I’m hoping to be able to push through the last 10k, but have always hit the wall in the past. I’m hoping the increased mileage and Z2 training will help this time around.

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