'Maximum' effective dose (diminishing returns) - Long Rides

germane to “do long rides” thing. a guy I follow locally who finished 2nd at mt washington made a long post about his training process. Last year he said he did massive easy volume (he’d ride 200 miles on many weekends) and lost weight (12lbs) and did worse than he had the prior year by a minute. He’s done a lot of time trialing, so more intensity (and added weight) this past year and he had his best time ever. So just adding lots of endurance, especially at the expense of other types of workouts, may not be the best solution