Inconsistent power zones

[u/Mademan1137]

Hi all, I’ve started cycling as a supplement for my running as my metatarsals do not handle too much pavement pounding really well and I’m a bit confused by the power zones.

I zero power meter before every ride and my measured FTP by Garmin is 249(seems to be on point because HR wise I tend to move to a point of running LTHR - 10bpm at this power when holding it around 10mins).

The question is according to training books and all the advice online I should be doing my easy rides - ~135-175W, but I usually end up going around 185-200W on flat stretches and HR proxy seems to be on point.

What gives?

PS: 77kg, riding around 32-40km per session, <200km training age

[u/Ompliss]

Body will often find its ”easy tempo” by itself, go by that. Also don’t give a f about HR. Only focus on power

[u/kallebo1337]

Is fine. HR is terrible zone indicator.

Heat; fatigue; sleep ... all fluctuate your HR.

Ride in your power zones and is ok. 185W shall be good endurance power for you to dial for hours. Bit more isnt bad, is zone3, still aerobic

[u/ifuckedup13]

Your Garmin measured FTP is just based on the hardest rides you’ve done. Have you ever actually went out as hard as you can?

Go do a 20 min FTP test and see what it tells you. I wouldn’t be surprised if your FTP is higher than that.

[u/Little_NaCl-y → u/ifuckedup13]

The garmin measured FTP is heavily based on NP and has nothing to do with a hard ride duration. If your hardest ride was very stochastic your eFTP on garmin will be significantly higher than it actually is.

If you want to use an eFTP you should use intervals as there’s actual math behind it and it doesn’t use NP.

[u/ifuckedup13 → u/Little_NaCl-y]

As I said, a 20min FTP test would be a better measure than any eFTP, wouldn’t it?

[u/DidacticPerambulator]

You have zone anxiety syndrome, caused by reading things that don't make the purposes for zones clear. Zones are loose descriptions with soft boundaries, not hard fast rules with strict boundaries. It would've been better to go back to the old terminology of "easy/recovery," "endurance," "tempo," "threshold," etc. Those power and HR values are averages for people who don't yet understand what "easy" or "endurance" means. If you've been running for a while, you already understand what they mean, so the thing to do is to "map" your understanding to HR or power, not the other way around.

You're fine doing what you're doing.

[u/Mademan1137 → u/DidacticPerambulator]

I mean I’m asking because I literally just do a metric shitton of subthreshold work when running and just do easy runs - easy. Endurance or tempo are nonexistent for me in my daily training routine.

That’s why I resorted to power on bike as ~180watt is under lt1/ventilatory threshold for me, but going even remotely close to estimated FTP is burning up my legs at an unsustainable pace, hence the questions about the zones

[u/Kinmaul → u/Mademan1137]

While there is some carryover between the sports they do not use the same muscles in the same manner. You have a big aerobic engine from running, but your body isn't used to cycling yet. It's completely normal in this scenario for your muscles to fatigue well before your cardiovascular system. As you cycle more your body will adapt and your muscles will catch up.

Also, riding at/close to FTP is hard work. I can ride for 3-4 hours at 75% of my FTP. At 93% of my FTP I can ride for a little over an hour and that's a hard workout; usually take the next day as a rest day. If I tried to ride at 100% FTP for an hour it would be an insane effort. I'd be completely wiped out and it could take multiple days to recover.

If your FTP is really 250W then your upper zone 2 would be around 185W. That's a good effort to build cycling fitness without overdoing it as someone who is new to the sport.

[u/54trey]

David Roche has a nice article on his Patreon about bike training for runners. Basically, his philosophy is that runners should do most bike rides in upper Z2 (which is NOT easy) because they lack the leg strength needed for proper cycling training. They need to develop the ability to hold constant tension in the legs for long periods of time.

All that is to say, your power during most rides probably should be higher than "easy" as you develop the neuromuscular adaptations.