Tech 3 Yamaha racer Colin Edwards trailed home in 13th position in Sunday's MotoGP race in Mugello due to physical problems with his arms.
Edwards, who qualified fifth, quickly tumbled down the order in the early laps. After dropping to 11th on the opening tour, he battled back to eighth, before dropping off the pace once more.
"I was out of gas after warm-up," he admitted. "We started getting arm-pump [a muscular condition in the forearm] on Friday – I never get arm-pump. We couldn't figure out what the problem was.
"We played around with it a bit... I wish I knew. I was huffing and puffing and gasping, but nothing was happening. The bike felt alright, but it felt like trying to steer a truck through those chicanes. I had to go slower and slower to keep hitting the apexes, and then it was like I might pass out out here.
"Speaking to Ben [Spies, his teammate] he had much the same feeling. The bike was good for four laps, then it was a handful. I think I need to take a nap."
Edwards has been strongly tipped to take over the injured Valentino Rossi's works Yamaha later this season.
Spies, who finished seventh, added: "It was so physical to ride the bike through these chicanes here. That, and a lack of top speed, made the race way too hard. I'm definitely feeling it after this race."