Originally Posted by
MikeOK
I am in Z4 most of the time, even light pedaling on the flats puts me in the bottom of Z4. I can't keep the bike upright and get in the lower zones. This is a screenshot of a typical ride with a few hills:
Your zones are incorrect. Z4 work requires rapid deep breathing where the ejection of single words is about all you can do. I doubt that's your usual state while riding on the flat.
That said, it is usual for newer riders to have much higher HRs for a given effort than experienced riders. This is normal, but not to the extent you show. As blood volume and heart muscle increase with exercise over time, HR drops because the heart ejection fraction increases. Thus HR zones must be repositioned to reflect these changes.