The evidence for Nadal being a chem-cheater has little to do with his musculature. What stands out is:
(1) He plays arguably the most demanding, highest-energy-expending game in tennis today, if not in tennis history. He stands WAY behind the lines, so he runs more and farther than anybody. He NEVER gives up on a ball, and seems to run down everything. And he swings at each and every ball EXTREMELY violently. So on each point, he is expending many times the energy of his competitors.
(2) Yet, he continues to be able to do it, not only week-in and week-out, but day-in and day-out. Indeed, he seems to suffer no recovery issues at all, which would be about as likely as a world-class marathoner running his best race, every day, day-in, day-out for a year. Which is to say: impossible, without "assistance." I should say, he seems to suffer no recovery issues at all, EXCEPT...
(3) ...For the frequent, minor injuries that have a tendency to crop up in those who subject their systems to chemical enhancements. Human physiology is not made to withstand the sorts of stresses that performance-enhancing chemicals allow it to. So eventually, something gives.
And, oh yeah, (4), as somebody already mentioned, there is an awful lot of "to do" about that left bicep, yet so much of the rest of his physique isn't what you'd expect of a juiced-up musclehead...right? Well, roids only work to produce musculature insofar as the person is willing to work the muscles. What they do is maximize the possible gains, primarily by allowing super-fast recovery so that you can get through the break-down/rebuild phase as fast as possible and start working again. That boost to recovery is why they're so popular among endurance athletes, too. Yet, why would Nadal (or anyone) work out his bicep so much harder? Well, he wouldn't, if bodybuilding were the issue. Yet, the amount of work that arm gets relative to the rest of the body through repeated stress COULD lead to muscular hypertrophy, if (and probably only if) it were subjected to those chemical enhancers. Put bluntly, you wouldn't expect a huge muscular imbalance -- no matter how hard one particular limb was worked every day during the daily grind -- in any body that WASN'T enhanced. The breakdown and recovery simply couldn't happen fast enough to produce that kind of imbalance.
So, tally it up. Prolonged periods of superhuman efforts, followed by layoffs that are the results of "minor injuries," and imbalanced muscular hypertrophy should be raising red flags with anyone interested in seeing the best interests of competitive justice maintained.
One would like to think that "frequent testing" would make this a non-issue, but of course, we all know that tennis doesn't exactly have a stellar reputation where fair-and-equal testing across the board is concerned. There is "rumored" :roll: history of big-name players being given a pass on positive tests for fear ratings and public interest will suffer. Tennis has a vested interest in keeping "The King of Clay" on the courts this time of year.
Not that I'm saying Nadal is doping/juicing, but you've got to wonder, when so much evidence points to it.