Hey, fair enough question, but don't jump to conclusions.
Peter has always "burned the candle at both ends," staying on the road 25 days a month, flying between time zones, staying up late, and getting up early. He's always been able to function on very little sleep, sneaking in his "power naps" when he needs them. Most of us lose the stamina to keep those kind of hours in our 20's or 30's. He's still trying to keep his normal pace; maybe age is finally showing.
I saw him last month and thought he looked fine. His energy levels may fluctuate more than they did years ago, but he's still a joy to watch.