Its easy for a guy that's been racing for years to do a regimented program solo. I suppose its easy for everyone but my point is newer racers should be either racing or riding in a fast group at least once a week. If I'm doing solo stuff for a few weeks I am definitely a tad bit off during a race. The purpose of a fast group ride for me is to acclimate so I'm not a **** during the race.
Twenty hours a week is pretty crazy. I do about 10 and I'm constantly tired. Of course, Intensity + Duration = Load and noodling for 20 hours is easy but doing real work at that volume would destroy me.