Carbonfiberboy 

I think the issue is that the bolded is still poorly understood. It's insanely complicated. I've tried to read papers about that but I think one would need a PHD in human specific organic chem and be up to date on all the latest research to understand them. Degrees in the mathematics of biology are sought after. So we fall back on empirics perhaps better to say, one has a hypothesis, one experiments, one develops a theory based on experimental results. The problem is trying to eliminate the randomizing produced by the variation in individual biology, which obviously varies quite a bit.

But yeah, I strength train for two reasons: to prevent injuries and to increase endurance. A side benefit was sprinting performance, which was fun but had no practical application for endurance cycling other than the usual beating up on other riders. IME very few endurance cyclists strength train, though the ones who do get results, Peter Sagan for one. Not too many riders are open about their training, and why should they be? Sagan used to have a video up with high rep heavy squats, etc., but it's been taken down, maybe an issue with his team. Now all that I find is him doing callisthenic type work and stretching Boring to most people. We're in nutcase territory here.