Originally Posted by GhostRider62

Here is the thing, I doubt there is any way in the world for me to gain 5 % even with the best coach and hardest work. A fit might get me 2% and I would be giddy with that. I cannot see how some random 4 hour ride could discern such a small improvement. OTOH, I know my PD curve very, very well and hills do not lie. Thus, there is less energy expending going slowly up a hill in the heat.