I hate asking this...but I'm so lost in my zone2/endurance rides

I know this has been discussed to death on the internet. I’ve gone through so many forum posts, podcasts, videos about endurance rides, but I’m still so lost in my particular case. I cannot reach my zone2 HR without my legs falling off. I feel like I’m still not understanding how to gauge what zone 2 is. (without lactate meter). Sometimes I feel like I’m wasting my time doing endurance rides because they’re actually not hard (on the heart) enough. But they feel hard on the legs :frowning:

Some basic stats about myself:

  • My Max HR is 200. (as seen from chest strap)
  • My FTP is 230, if I ride around this wattage for long duration, my HR will eventually climb to 180ish bpm.
  • I can ride at 200W at around 165bpm comfortably for maybe 1 hour. So sweet spot percentages seem accurate
  • I weigh 63kg, been doing structured training for 3years now.
  • Age 35Male
  • Average 12~13hours a week, 500~600TSS. Only 2 intensity days, rest are strictly endurance rides, not Sweetspot, not tempo.

According to calculations:

  • My zone2 Power (56%-75% of FTP) at 128w~172w.
  • My zone2 HR(70%~80% of max) at above 140bpm.

From my endurance rides, I can ride 3 hours at 130-140W(low end of zone2) and my HR is at 125BPM. In order to get to 140bpm (low end of zone2 HR), I essentially have to ride at high end of zone2 power, which I cannot do without FRESH legs feeling like they’re burning after a few hours.

Then there’s the school of RPE, and “you should be able to ride at zone2 all day”. At RPE of 3-4, aka all day pace, I can only produce maybe 130Watts, and my HR sits comfortably at 120bpm, which is essentially recovery…I don’t think I ride at 160watts all day without accumulating a ton of fatigue on an “easy day”

There’s also the talking test, I can talk perfectly fine riding at 160-160w, but I can’t hold that all day because of my legs…

There’s also a big caveat that I do my zone 2 rides the day after my threshold/vo2 max days. My legs already start off like jell-o, and I worry that riding to reach 140bpm will totally ruin me for my next hard workout day.

below is a typical zone2 indoor ride:

Does anyone else experience this? Where their zone 2 power is like zone 1 HR? Should I suck it up and just ride at whatever it takes to get to zone 2 HR, even if my legs are hurting? And hopefully I can recover on time before my next hard workout? (I doubt i can)


Don’t stress about how much power is required to align with some arbitrary HR zones you’ve calculated. Don’t chase that.

Not that it matters much, but I would suggest using LTHR / FTP HR / LTHR (lactate threshold HR) to calculate zones below FTP.

So if your LTHR is 180bpm as stated, then rough zone2 using Coggan classic HR zones suggests endurance is 69-84% or 124-151bpm and by power its 129W-175W.

Consistent with Coggan HR zones that I calculated above, both HR and power at bottom of zone.

By default Intervals uses Friel HR zones, which are higher than Coggan HR zones. Zone2 HR by system:

  • Coggan suggests 69-84% of LTHR
  • Friel suggests 82-89% of LTHR
  • not as familiar but believe USA Cycling 5 zone uses 66-73% (LTHR I assume)
  • not as familiar but believe British Cycling 6 zone uses 66-75% (LTHR I assume)

A few points about endurance riding:

  • build up conditioning to do hard interval work or racing
  • aerobic conditioning of the heart
  • building metabolic fitness in leg muscles

Do them by RPE and don’t worry about aligning power and HR.


HR zones based off percent max heart rate are extremely imprecise/inaccurate. I wouldn’t worry too much.


If you are doing the workout in ERG (looks like it) have you tried a higher gear (big ring in front, smaller ring in the back) or maybe resistance mode?

Does RPE of 3-4 make sense for endurance? Also my RPE for legs and RPE are sooo far apart from one another. I assume RPE of how legs feel should be used in this case?

I have! It’s about the same except I have to pay more attention. Without ERG mode, my power tend to dip a bit, and my HR dips with it too, and it really starts to look like a recovery ride.

On of the biggest things i learned from listening to a lot of the kollie moore stuff was that zone 2 should be easy.

Not doable for a long period, but easy.

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Just don’t let your endurance work interfere with interval workouts. Once you get past that we could start debating the performance benefits of training higher in zone2.


If you’re doing your Z2 rides the day after a hard workout, there’s a good chance residual fatigue is preventing your HR from climbing to where it would be if you were fresh.

Personally, I notice a big decrease in the amount of burn I feel in my legs during my evening trainer sessions if I have a banana or other carbs before getting on the bike rather than just relying on my lunch from a few hours earlier.

This should be a red flag…


Have you looked at the power tab on intervals.icu for your Z2 rides? You could use Power/HR to assess how your HR is responding to a combination of power and duration.

So if your Power/HR is basically pretty much flat for a 2 hour ride at X watts and the RPE felt about right, next time up the power by a handful of watts and see what happens to Power/HR in the second hour compared to the first hour.

If it’s still basically flat, just repeat the same process next time. If there’s clear decoupling btwn power and HR, that’s a sign - assuming RPE is about right - that you might want to keep your endurance riding at that power for a bit and see if training with more rides at that same power level helps build your endurance so that the decoupling reduces to near enough zero.

Long term, bulld out duration (slowly) and power (even more slowly) over as many years as you have left. :wink:

I did a 2 hour endurance ride (65% of FTP) after a Zwift race today. Here are screenshots from intervals.icu so you can see what I’m talking about.

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first post:

Steady power, and HR looks flat to slightly declining. No decoupling for that 2 hour example.

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Yeah, I saw. Great! Add 5 watts and see what happens. Repeat. Any drawbacks to that as a plan?


big ring in front also? higher flywheel speed can make a big difference in feel

If his RPE is high, why raise power? Comes across as a some arbitrary belief system that everything must be progressed, always. My first thought is staying the course and let conditioning come to me.

We don’t even know how much training/riding the original poster is doing.


this is what mine looks like for 2.5hours. Does this show that my power went up and HR dropped? We want to see the two lines matching right?

I’m doing about 13hrs of cycling a week. including 2 hours of active recovery at maybe 80w.

Their RPE wasn’t high on that ride. They said that at RPE of 3 or 4 they’re doing 130 watts. On that ride they’re doing 131 watts. That ride is the start point for what I’m suggesting ie calibrating their endurance pace …

… which is what they asked for, I thought.

yeah I’m probably losing the plot, but there are a lot of misconceptions about how to set zones and use metrics like decoupling.

And maybe I missed it but we don’t have the big picture - training load, training age, etc.

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You’re definitely reading it correctly. If it was me I’d add 5 watts next time, see how it felt and then look at the data :+1:

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Definitely a lot of navel-gazing, especially when it comes to the dreaded “Z2”.

I think what I’m suggesting is a half-decent way to very slowly increase power in the absence of a solid RPE gauge, given that the start point is negative decoupling.