How hard to go on intervals

I do not have a power meter so train with only HR and RPE. I realize that for shorter intervals, HR does not respond fast enough so I am left with RPE In this case, I pretty much go as fast as I can do for the given time period, while trying to keep the effort steady. I always do my intervals on the same stretch of (uphill) road so can gauge my effort by how far I go, too. I feel that I pace my workout fairly well, with very little variance in the distance that I travel for the given time period. Since I have no real idea what % of FTP effort i am doing, is it possible that I could be doing my intervals too hard? Or is the point to always go as far as I can in the given time period?
Note: I am talking about shorter intervals here ( < 5 min ). For longer efforts, HR help a lot more.


Perfect. Literally don’t change a thing.


It is certainly possible. Do you ever do efforts on a trainer for comparison of RPE?

Don’t overcomplicate things. Intervals at either MAP or anaerobic (heck, even threshold) power levels should be done at an all out power level sustainable for the duration you’re working on the rest interval prescribed, not a % of FTP. If everyone did what this rider is doing for their short intervals, their training would be more productive.

Dead serious here, @orangeJ you are doing these intervals perfectly by going as hard as you sustainably can and judging that by how far you get on the climb on each effort. When you go substantially shorter on an effort, call it a day.

Zen master short interval status here. Don’t let anyone tell you otherwise.


As @kurt.braeckel has indicated, you have perfected the execution of these type of intervals. They have nothing (or very little) to do with %FTP. There are entire threads on here dedicated to over-complicating what has to be one of the simplest workout prescriptions known to endurance athletes.

Sounds harsh but :man_shrugging:.

Congratulations on avoiding the second-guessing, over-thinking, and forum debate that always happens when you don’t do exactly what you described above.

Kudos to you.


When I ran a lot I was often told that in training you should finish your last interval knowing you could do another if you ABSOLUTELY had to but you’re VERY glad you don’t have to…same applies to cycling I think :grin:

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Definitely does :+1:

And for the same reason.


THIS. @kurt.braeckel said it best.

Also, OP, listen to Kolie Moore’s Empirical Cycling podcast about VO2 intervals. High Cadence, high heart rate - who cares about power - highest power you can sustain for the prescribed intervals.

I am of the opinion that locking yourself into a % FTP for VO2 is short-changing the athlete - and should be done outdoors ignoring power or in resistance mode on the trainer - you should be gasping for air by the end.

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Yup, for these VO2 type intervals you really can’t go too high in power. Maybe the first one can be but you already said ‘sustainably’ so I think you’ve got that covered.

Really, the only thing you are missing by not having power is

  1. Not being able to track progression. Though you can probably get decently close with your relative distance, just not as granualar.
  2. A bit harder to tell if your power has dropped too much to be productive any more. But I think this can also be gagued by either distance up the hill or just a super high RPE.

Keep doing what you’re doing.

Before I had power - I used a 4ish minute hill around me as a guage. I just looked at the strava segment times afterward to gauge relative effort. Now, I look at the average power across intervals on after the ride

I think youre probably doing this better than most people with power meters to be honest…

For the first few months with my coach, he told me to remove power from my head unit. Everything was on HR and RPE. I thought he was nuts, but it made me start to appreciate my actual HR zones and have a good idea where I was without looking at anything. When I was doing intervals purely based on power, I was hitting Z5Hr way to long and often, which meant my recovery was complete crap.

Youre absolutely correct that HR isnt going to respond quick enough for short intervals, but its a great metric for the longer ones at LT or AP

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Thanks everyone for the great feedback! I especially like the advice to not overthink things, as I tend to do that. Also great to hear from those who have made progress w/o a power meter.

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