Hey Lady TT, no worries. Glad to share some of my perspective. I'm not sure everyone will agree with everything we all have to say, but that's why we can have good discussion here. There's always room for healthy dissension here, not some of the sick hating stuff one sees at other forums.
I'm still trying to get a handle on the fitness factors. Not always sure what General Hercules means about the lean muscle mass, that oxygen level thing. I know he is into cycling, so maybe he can elaborate on some of this, especially in terms of Rafa. I can only look at it from what I know in layman's terms. I know if I'm out 4-5 hours playing tennis in the hot sun with either a ball machine or two people hitting to me almost everyday or even every other day on the rowing exercise machine, I'll be pretty fit in just a few weeks. But I know you have to be pretty injury free to practice and train with intensity, and you have to have the dedication to do it without much distraction, and the recognition either by yourself or a coach to target specific areas of your game that either need reinforcement (your strengths) or improvement (your weaknesses).
For example, after losing to Novak at Indian Wells, Roger said he wasn't too distressed about the loss, and that the match gave him information on what exactly what he needed to work on, and while players were playing Miami, he would take a few days off, and then train hard on these things on the clay in Switzerland to be ready for Monte-Carlo. Let's hope Rafa can also get some good training in prior to that tournament since he went out relatively early in Miami. I have a feeling this will be a very interesting clay season. Hopefully we can get some videos/pics from their practice sessions.
Respectfully,
masterclass