So true.
A few years ago, I did my fitness test one month before I turned 50. My good friend who is 47 was in my group, plus 7 others. Of those 7, one was in his 30's and the rest were young Airmen in the 20's.
I finished first in the 1.5 mile run, followed by my friend about 25" behind me. The two of us stood by the finish line and yelled "old guys rule!!" to the rest of the runners as they went by. It was pathetic to watch the ones in their early 20's struggling to make it 6 laps. They should be in great shape, and certainly good enough to beat a 50 year old Lt Col with an artificial hip.