Cumulative fatigue. You just ride the fatigue out of your legs and your body has forgotten what feeling good feels like because you’re never recovered. So when you ride easy you feel the chronic fatigue you’ve built up.
There are many reasons.
You haven’t specified whether this is indoors or outdoors or both, so let me address both. On the trainer, the biggest two factors that make Z2 rides hard, especially those longer than 2:30 hours, are boredom and saddle discomfort. Basically, it is boring, too hard to be easy and unlike harder workouts, there are no rest intervals. Personally, I don’t like watching TV or so, and usually cannot stomach listening to a podcast the entire time. So I have to combine things. Let me add a third point that isn’t a factor for me, personally, but might be for you or others: proper fueling. Also endurance rides should be fueled, especially long ones. In my experience, 80–100 g/h work very well. Taking in carbs is known to lower RPE.
Outdoors, personally, RPE is not a problem, provided I picked the right route and can govern my enthusiasm. Outdoors it is so easy to just want to smash it, especially if there are hills or longer climbs. My trick here is to get on my mountain bike, hitch the bike trailer to it and ride a loop along the coast with my daughter. I pace by heart rate.
Lastly, let me reiterate one thing the others have said: long endurance rides are a different beast than recovery spins. Endurance rides do incur fatigue even if you don’t feel it right away. So you should be well-rested and fuel properly. Also rest afterwards if you can.
I don’t think that’s what’s being described at all.
It’s certainly not true for me. I can do a Zwift century no problem and my biggest event this year was 10h30 ridden non stop (literally).
But when pacing at sub Z2, there’s just this nagging sensation that something is missing. Up the pace to tempo and it disappears.
Last week I noticed it when I took a long warm up spin to a group ride. For 90minutes I felt awful. Despite being fresh, fully fulled and sipping carbs. Then I realised I was pushing my luck to be late so I upped the pace to sweetspot and it was like I was floating along- I felt brilliant!
Then smashed the group ride, (340w for 1h01) and felt great.
6 miles home at z2- felt awful again
Your bladder is my hero!
(But seriously, 10:30 hours indoors, that’s massive.)
I think I have mentioned exactly that issue for outdoor rides: you need to be able to govern your enthusiasm. All of us like to smash it, but endurance rides are like the vegetables that are good for us and that we need to eat. Whereas hard rides are the tempting ice cream, the juicy steak, the delicious chicken wings. I love the feeling of being able to pull off x watts without feeling much in the way of fatigue. But you gotta eat your vegetables to get stronger!
10h30 was outdoors thankfully - a gravel event.
It’s not a pacing issue, or a motivation one. It’s a physical sense that something is missing.
I guess a glucose monitor might shed some light on it.
I was so glad to hear the OP say it because I’ve been banging on about it to mates for the past ten years
That’s what I am saying, you are going faster than you should, because you want to. You cannot or don’t want to govern your pace.
This is not the reason.
Its probably already been said @Dunk but sometimes you just get in the zone (pardon the accidental pun) and are motivated on those days tempo/ss feels relatively free flowing where as on other days endurance rides can seem more of a drag a lot of it is psychological. Lol I can have it during one ride, it can feel a drag at Z2 but with a little bit of motivation (sometimes due to the higher tempo its self) suddenly tempo/ss is free flowing.
Though i always struggle with motivation for zone 2. Possibly just mental as i doesn’t release the endorphins that higher zone work does,
@OreoCookie both indoor and outdoor.
I’m not going faster than I should? I’m really good at pacing recovery and z2 rides and have excellent decoupling rates over say 6hrs.
But it feels harder, physically, than Z3 and above does.
220w feels harder than 270. Obviously it’s not, and I’ll ride much further at 220 but in terms of perception- it actually, tangibly, physically feels like I’m doing something that is materially tougher.
Six hours of Z2 feels harder than six hours of Z3?
No that’s not what I said.
I said obviously I can do the lower wattage for longer but the entire time my RPE is higher at Z2.
If I attempted 6hrs of Z3, RPE would start lower then probably increase as my wattage dropped and the Z3 became Z2 anyhow.
How are you determining zones by power or heart rate?
And how did you determine the top of your Z2 power?
Around 75% of ftp but it would be unusual for me to ride a Z2 paced ride that high. Usually closer to 60%
I having a hard time following duration. What is your usual duration of a 60% paced z2 ride? For example all my z2 workouts up to 3 hours are targeted at 70-75%.
It depends. Can be anything from 45 mins to 10.5hrs.
And just to reiterate. I’m not saying Z2 is harder than Z3. I’m saying it always feels like it is and always has done for the last decade since I first bought Joe Friels book and knew what a zone was.
If for example, you gave me a blind ERG test, ramped up over 5 mins to either Z3 or Z2, I would report my RPE to be higher in the Z2 setting.
So interestingly, doing endurance rides by RPE would almost certainly result in me going too hard.
It’s called “Happy Hard” for a reason right
With the survey results from TR workouts the team will be able to speak to this. I wonder if there is a subgroup where RPE is a different shape than what is expected? e.g. RPE curves where Z1 and Z2 work are reported as harder (REP) than zone 3. I know there are riders who over report (RPE vs lactate) zone 3 and 4. Could be another way to help shape workouts and tailor programs for athletes of different types. Power Curve and RPE curves. Sounds like a podcast topic.
I do agree with the posters upthread - - even if it feels better from an RPE perspective, too much happy hard, when you are meant to be getting zone 2, is going to lead to over reaching eventually. Been there and done that one.