In the NFL, shelf lives are extremely short. When researching for this article, I stumbled across the fact that not a single running back over the age of 31 had even one rushing yard in 2012.
But backs aren't the only football players who don't age well. In fact, it was extremely difficult to find 10 guys who have remained productive and valuable beyond their 35th birthday.
Caveat: It's possible that in some extremely unlikely scenario, I missed someone. If you believe that to be the case, make a case for him in the comment section, and we can break it down.
Caveat No. 2: In order to be considered, these old men had to be under contract with an NFL team. No lingering free agents allowed. However, I made an exception for John Abraham, because he's almost certain to sign somewhere before the 2013 season starts.
Without any further ado, here are the NFL's top 10 players born before June 1, 1978.