You can't pull the brake lever, you can barely move your fingers enough to hold on to the bike because the trapped blood in your forearms makes gripping nearly impossible—you have compartment syndrome, known as 'arm pump', the destroyer of motorcycle racers. Anyone who's ever tried seriously to improve as a motocross rider has experienced arm pump. And although you might need to move up the ranks in short-circuit racing before it afflicts you, it's still almost inevitable, unless your name is Valentino Rossi.
MotoGP recently released a video on YouTube of last September's Hall of Fame dinner, which included Rossi, Dani Pedrosa, Casey Stoner, Giacomo Agostini, Jorge Lorenzo, Freddie Spencer, and Kevin Schwantz. At one point during the dinner, the discussion turned to arm pump, which is when we found out that Rossi won the MotoGP genetic lottery and never suffered from it during his career. The conversation was even more contrasting because Pedrosa was involved and suffered massively from arm pump throughout his career.
Rossi told the group, "I've had it a bit with motocross sometimes, but in MotoGP, never... In my opinion, it’s genetic luck,” continued Rossi before saying, "It depends on your genes; how big your forearms are... That was a great luck [for me].” Now, contrast this to Pedrosa, who had the most extreme surgery you can get to solve the problem—removal of the forearm muscle fascia—and save his career in 2015.
