Rooney isn't a great example seeing as he declined badly around the age of 28. Hell, an argument could be had that his last great season was when he was 26. He kept playing for quite a while after that but he wasn't close to the same player anymore.
I'd also say that Giggs was a 'physical freak' in pretty much the same way as Ibra was, just without the size. Both were blessed physically and then looked after themselves incredibly well, keeping themselves at a perfect body weight, doing yoga and focusing on flexibility, etc. The fact that a 40 yo Giggs who was protecting his hamstrings by not running at full speed was still faster than most players says it all.