Zone 4 Workout Question

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  • #24267

    Hi there

    I am doing the 20 week Intro to Ultra Running plan and have started doing the Zone 4 workouts.

    I notice that my heart rate lags when I increase my pace uphill and takes a good 45-60s to get into Zone 4. Similarly when I slow down it takes about 30s for my HR to decrease to Zone 2.

    How do I account for this with the Zone 4 workouts which rely on timing and with short intervals? Should I just start counting from when I increase my pace to what I know will get me to Zone 4 and stop timing when I slow down? Or should I actually go by my HR and ‘guesstimate’ when to slow down to hit the 2 minute mark? I feel relying on the exact HR time in Zone 4 will be tricky for the 30-30s given the lag in HR and short intervals.

    Lastly, I noticed for one workout it talks about doing 2×8″ hill sprints. Should I walk between the hill sprints rather than totally rest (like the specific hill sprint workouts), if this is supposed to be part of a warm up?


  • Inactive
    Anonymous on #24348


    The best benefit for the Z4 interval workouts will come from spending as much time as the plan calls for actually in Z4. It does that a minute to come up to full Z4 levels and then some time to drop back to Z1-2 levels during the rest intervals. You should try to get the specified time in Z4 for each repetition rather than just going by the watch time from when you start.

    For the 8 sec hill sprints you should take long recovery between. Typically this means walking down hill to the start very slowly for 2-3 minutes.


    Anonymous on #24362

    Remember that HR is the tail of the dog. Your pace is what’s wagging it. Without flat terrain or power meters, we’re left with HR as an intensity measure. But as you state, a lagging intensity measure is not ideal.

    For 30-30s, I try to go by pace rather than HR, but it takes a while to learn what that target pace is.

    Jo on #24401

    Great thanks for the advice. Tried the 30-30s today and aside from tripping a few times because I was looking at my watch so much and losing track of where I was at with the time occasionally it was ok. I definitely got a bit better sense for when I needed to speed up/slow down by the second set. Looking at Training Peaks graph afterwards I think it took a bit more time for my HR to come down after I slowed my pace towards the end of the last set which makes sense and is something I can account for in the future.

    Thanks again!

    Anonymous on #24418

    What type of watch do you have? If it’s a Garmin or Suunto, you can build workouts ahead of time, and then use the watch’s alarms to tell you when to start and stop intervals.

    I’m not familiar with Suunto, but with Garmin, you can build workouts in their Garmin Connect app and then sync them to the watch.

    Jo on #24474

    I have a Garmin watch…I will totally look into this. Might help me from falling flat onto my face because I’m too busy looking at my watch next time I’m doing 30-30s 😉 Thanks!

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