Phil Mickelson won the PGA championship at the age of 50 (almost 51 as a matter of fact!) This sets the record for the oldest champion of a major tournament in men's professional golf. Interestingly, Phil is also eligible to compete in the Champions tour (formerly known as the Senior tour) but his win guarantees full exemption status in the PGA tour for the next five years.
In his post-win interview, he mentioned that he undergoes a fasting period for 36 consecutive hours each week to reset the body. He probably undergoes more physical training now than in his prime days. However, with the way he is going, who knows, maybe his prime is still ahead of him!
Phil Mickelson's win shows that old age doesn't necessarily equate to declining performance. Age brings wisdom and experience, and if combined with proper conditioning, the combination can prove to be a winning formula!