For most running backs, turning 30 signals the end of the line, the time to start slowing down and thinking about life after football. But for Chargers RB LaDainian Tomlinson, hitting this milestone birthday could indicate a new beginning.

Tomlinson, who celebrated his 30th birthday on June 23, has made it his goal this season to prove that age is merely a number. In fact, he’s eager to show that he can be better at 30 than he was at 29.

Hampered by a sore big toe for much of the 2008 campaign, L.T. was not his usual self. Besides finishing with career lows in both carries (292) and rushing yards (1,110) and registering a meager 3.8 yards per attempt, the veteran lacked his trademark burst, elusiveness and cutting ability. Although Tomlinson’s numbers on the ground still ranked among the league leaders, they were far below the 338 carries, 1,521 yards and 16 touchdowns he averaged in his first seven years as a pro.

Things didn’t get any better for the five-time Pro Bowler after the regular season, as a groin injury forced him to miss a large portion of the wild-card playoff game and all of the divisional-round contest. Then, offseason contract issues nearly had the Bolts parting ways with their most accomplished player before GM A.J. Smith ultimately reworked Tomlinson’s deal to keep L.T. in San Diego.

Fast forward to the spring and summer, though, and it was as if he was a completely different person. The way we hear it, not only was he completely healed from his bevy of ailments, but he also looked as fast, athletic and energetic at minicamps as he did in his early 20s. We understand that No. 21 looked more like a youngster ready to have his best season than a 30-year-old coming off his worst year.

Signs point to a bounce-back campaign from Tomlinson, who trails only Emmitt Smith for the career rushing TD record. Unlike last season, his offensive line is now fully healthy, and his lead blocker, FB Jacob Hester, is more experienced and well-rounded entering his second year. Age could be the one thing that slows him down, but it doesn’t seem to have hindered him thus far.

L.T. has just about everything but a Super Bowl ring. With a vintage ’09, he might have that, too.