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.
OK, so Plaxico Burress isn't the player he once was, but the Pittsburgh Steelers wide receiver has done just enough to sneak into the bottom spot.
He had only three catches in three starts after returning to the Steelers late last year, but the former No. 8 overall pick had 612 yards and eight touchdowns with the New York Jets in 2011. That year, he was by far the best receiver in the league among those 34 or older.
And keep in mind that there are no more than a couple dozen active NFL players over the age of 35, so this isn't exactly high praise for the guy.
When you hit 35, merely staying in the league is an accomplishment. Yeremiah Bell might not be a special player, but he's staying employed and staying on the field.
The safety started all 16 games for the New York Jets last season and has missed only a single start since 2007. He signed with the Arizona Cardinals earlier this offseason, and Kent Somers of the Arizona Republic projects that he'll start there too.
Pro Football Focus ranked him 55th last year among 88 qualifying safeties, and the former sixth-round pick didn't force a single turnover. But you know what you're getting with him, which is why he won't go away.
A lot of people have given up on former Defensive Player of the Year James Harrison, who has missed eight games the last two seasons and has seen his sack and forced fumble numbers drop consistently. But after he toiled on the open market for quite a while, the Cincinnati Bengals decided to give him a shot.
That could pay off, because a motivated Harrison is a dangerous Harrison. And keep in mind that he still managed to put together five sacks in the last seven games of the 2012 season with the Pittsburgh Steelers.
Expect Bengals defensive coordinator Mike Zimmer to squeeze some juice out of the four-time All-Pro as he shifts into a SAM linebacker role in Cincinnati's 4-3 defense.
Ninety-five days: That's how long seven-time All-Pro defensive back Charles Woodson sat unsigned on the free-agent market this winter and spring before finally reuniting with the Oakland Raiders.
Woodson missed the majority of the 2012 season in Green Bay due to injury, but the guy had seven interceptions only two years ago and was Defensive Player of the Year only two years before that. Even in seven starts last season, the guy had a pick, a forced fumble, 1.5 sacks and 38 tackles, earning a positive PFF grade in his first year as a full-time safety.
That's the role he'll play in Oakland, where it wouldn't be surprising to see the former Heisman winner put on one last impressive show.
London Fletcher, who is easily the oldest player on our list, has managed to make the Pro Bowl each of the last four years. He's not only a natural leader who brings intangible benefits to the Washington Redskins defense, but he continues to be a force in the middle of that linebacking corps.
Fletcher did miss 21 tackles last year, which, according to PFF, was the second-highest total in the league. But the good still greatly outweighs the bad for a heavy hitter with great range and top-notch instincts.
This might be Fletcher's last year, but if that's the case, he'll walk away on top of his game.
Despite the fact he had 10 sacks while forcing six fumbles as a situational pass-rusher with the Atlanta Falcons last year, John Abraham has yet to find a new job after becoming a cap casualty earlier this offseason in Atlanta.
There's no way that'll last into the season, because the NFL's active sack leader is still getting it done. He was rated by PFF as the fifth-best 4-3 defensive end in football in 2012 after bringing the heat for all 16 regular-season games. In fact, the three-time All-Pro has missed only two games since 2006.
Abraham seems to be taking a stubborn approach to free agency, but he's too good to remain on the market much longer.
After breaching the triple-digit total mark while also holding it down in coverage with a trio of interceptions, Antoine Winfield was rated by PFF as the best all-around cornerback in football last season. For a 35-year-old, that's simply amazing.
The three-time Pro Bowler has jumped from the Minnesota Vikings to the Seattle Seahawks, where he'll have less pressure while maintaining the ability to flash his versatility and playmaking nature as a nickel cornerback.
If he can stay healthy, there's no reason to think Winfield won't be one of the league's best defensive backs yet again.
After flirting with retirement early this offseason, the league's best 35-plus-year-old non-quarterback is returning for one more kick at the can. And there's no reason to believe that Tony Gonzalez won't continue to perform like one of the best tight ends in football.
The 10-time All-Pro (you read that correctly) is coming off a 93-catch, 980-yard, eight-touchdown campaign. He hasn't missed a start since 2006 and hasn't had fewer than 70 catches, 650 yards or five touchdowns in any of those seasons.
In fact, only he and Jerry Rice have caught at least 70 passes in 13 separate seasons. The guy is a legend, and he'll keep building on that with the Atlanta Falcons in 2013.
Tom Brady wouldn't have been able to qualify for this list one year ago, but he'll turn 36 before the 2013 season gets underway, and he hasn't lost even a partial step from his "prime."
His numbers took a slight dive, with injuries slaying many of his top targets last season, but Brady still ranked in the top six in the league in yards, touchdowns and passer rating while leading the New England Patriots to another double-digit-win season and division title.
Don't expect the three-time Super Bowl champion to start fading just yet.
I don't think anyone would object to either Brady or Peyton Manning in this spot, but we're giving the edge to Manning because he's two years older than Brady but managed to post the better passer rating, average, touchdown total and completion percentage in 2012.
The four-time MVP might not have Aaron Rodgers' ability at this point, but you can't place any other active quarterbacks ahead of him after such a stellar campaign with the Denver Broncos.
The neck is fine, and now Manning has a full year under his belt in Denver. With Wes Welker joining the fray, too, expect No. 18 to have another huge season at the age of 37.