Why?

paul jones 64

Why am I finding it so easy to run in HR zone 2 but find it so difficult to maintain zone 2 on the bike. I’m good for maybe 1 to 1.5 hour but after that , nope. I’m following a half distance training program which requires up to 4 hours zone 2. I’ve tried high revs low power and low revs grinding. Just can’t maintain 128 +
Running at HR 150 all day long. Any advice ?

Ynnec

Do separate HRmax tests for both running & cycling and derive your zones from those.

It's very common for peeps to have a higher running threshold (~10bpm) than that when cycling.

All the best.

Gobi

PJ - do you mean you are running out of gas so HR is dropping due to not being able to maintain effort ?