Can’t sustain ‘all day’ pace

UPDATE: Thanks all for the great advice. Longer rides + proper nutrition (I’m not getting anywhere near enough carbs) seems like the fix.

Zone 2 is frequently touted as ‘all day’ pace. Problem is, I can’t sustain it beyond about four hours let alone all day. This is going to be a big problem with some long, tough events I have coming up this year.

Here are my numbers from a recent 6.5hr century. According to my FTP (268) zone 2 should be 150-201w. As you can see I’m at the bottom end of that and was pretty cooked by the end.

First quarter - NP = 153w
Second quarter - NP = 151w
Third quarter - NP = 150w
Fourth quarter - NP = 145w

Is it just a case of building that aerobic base? More training, more long miles? I’m on low vol Gran Fondo with longer weekend rides where I can (not often).

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Yes! And highlights nicely my own personal mindset shift away from focussing on FTP to Lt1 (etc).
(FTP for vanity “My Zone 2 is (on paper) x watts!”,
Lt1 for sanity “I can actually ride at x watts for 10hours!”)

TR has oft-said that growing your FTP is the tide that lifts all ships. Because mathematically, it seems to raise all of your percentage based zones.
But it seems to me that actually, it can just drag your FTP away from your Lt1!
So as you have discovered, you haven’t actually magiced up a big diesel engine, you’ve just strapped a huge turbo to the same 1.0l runaround that you started with :grinning:


How many hours per week can you train?

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Same here, TR tends to give too tough Z2 trainings.

As I don’t have my LT1 from lab tests, I used formula from this blog Polarized Training - A Detailed Look (Faster by FLO Podcast #13)

In short: LT1 = (HRmax - HRrest)*0.6+HRrest .

Note: HRrest is resting, not sleeping HR.

With this i feel my Z2 workouts on a trainer finally aren’t destroying me.

Best regards

At what point does breathing become difficult to hold a conversation?

If you’re not eating / drinking enough then longer rides can be really hard. Also, if you’ve not recovered from previous workouts or have had a tough week at work then that can have an impact.


About 4 or 5 hours at the moment.

TR makes a big deal that you can prep for a Gran Fondo on nothing more that 1.5hr training rides but I just can’t see how that will work for me.


If you can ride 4, but not 6, I’d say your food is off. If you are in calorie deficient, it will catch up to you.


Could be the case. I’m eating every hour on the dot; banana, flapjack, half a PB&J sandwich.

Does that sound low?

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Yes, training more, just more, is going to help this. Ride longer at zone 2 and that aerobic system will improve. It takes a lot of time, but spending that time is the way to get there.

Personal anecdote as a former bike messenger… I spent about 8 hours a day riding my bike while working as a messenger. Before that, I rode bikes for fun all throughout my early teens. Going FAR was way more fun than going hard, and subsequently, I got really good at it. I am no longer a bike messenger, but my aerobic system is disproportionately developed compared to the high end. I find that my zone 2 is far “larger” that most people’s. I can ride in “tempo” (above 80-85% ftp) territory for hours on end while easily maintaining conversation and breathing through my nose. However, since I’ve done far less high end training, I “underperform” as the intensity ramps up.

Also - it sounds like you’re not eating enough. For rides that long, you should be eating at least 75g of carbs per hour, and what you mentioned above doesn’t even come close to that. So, eat more, and train more!


Maybe try liquid calories?


A dedicated period of base training, followed by more carbs, has largely fixed this for me.

My FTP currently sits at 275 (NP over 45 minutes - that’s the test I use). Yesterday, I averaged 179w average, 199NP for 3hrs 58 mins. Av HR 136 (my max is 186). This is with a 30 minute sweetspot effort in the last hour.


For context, this was a hilly group ride, with some waiting at the top of hills.

3 months ago, the same ride saw an average power more like 170 (185NP) with an average HR of 147. FTP has only gone up 7-8w (and that reminds me to update it in Training Peaks, actually).

Lots of easy sessions, a few long SS intervals, and upping to 60-70g of carbs an hour, eating every 30 minutes, has made a huge difference.


This sounds like solid advice - appreciate the detail

If I read this correctly you are eating once an hour on the hour? If that is the case, switch to eating every 15 minutes starting immediately.

Also, how much in total calories are you eating per hour?


A quick check tells me my bars are 250cals, and what’s a banana? 150cals?

Sounds like nutrition likely biggest culprit. How am I going to fit double the food in my jersey :laughing:


If you’re wanting to ride continuously, or otherwise not pick up stuff whilst out, think of a top tube bag. I’ve seen photos of pros training that way when they want long rides without a team car following.

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Yes Karvonen Formula. Works well enough for me @2.7w/kg endurance rides. But from what I’ve read in this forum LT1 is higher. Like a low tempo.

I’d suggest most people’s LT1 is a bit below Karvonen, but it’s obviously very individual.

Granted it’s possible to get a lot out of a little, but specificity matters and so does raw volume.

Other folks are also right to correct your nutrition, but no amount of nutrition will let your body perform at peak capacity when you train at 25% of your target event distance.

Do you have a breakdown of your heart rate for each of those quarters as well?

You can’t expect to have developed your all day endurance if you’ve never trained it. Those Z2 rides are not just filler between high intensity work as some would make out.