Originally Posted by
Carbonfiberboy
They're probably going quite hard. I don't know of anyone who climbs in zone 2, even on all day events. The best aerobic conditioning I've ever found is simply riding with a group that's faster than you.
I often climb in zone 2, especially if it's a long-ish social ride. Yesterday's ride was Mt. Hamilton, with a buddy who is fit but climbs a bit slower. 44 miles up-and-down, 5200 feet. About 2.6 W/kg average on the uphill part, right in the middle of my zone 2.