Anyone who is wondering whether James Harrison, who turns 37 in May, will be in shape when the Pittsburgh Steelers' 2015 season starts can put their doubts to rest.

The five-time Pro Bowler has been posting videos of himself in the weight room, and it sure looks like he is in playing shape.

Harrison's most recent video may be the most impressive. In it he is lifting 135 pounds with one hand:

Looks real bad at 135!!!

A video posted by James Harrison (@jhharrison92) on

Harrison has had a rather tumultuous go of it since he was released by the Steelers after the 2013 season. He had one unproductive year with the Bengals before re-signing with the Steelers in September 2014 so he could retire as a member of the franchise.

But Harrison wasn't done, coming out of retirement several weeks after calling it quits. In 11 games he played well, recording 5.5 sacks and 29 solo tackles.

Much of the reason for Harrison's success at his age is due to his incredible work ethic. A scrappy, undersized player who went undrafted out of Kent State and spent a season playing in NFL Europe, Harrison has proven that he is willing to log countless hours at the gym.

No workout clothes, no problem for Harrison. He'll lift weights in a suit and tie.

Working everyday

A video posted by James Harrison (@jhharrison92) on

Lifts that seem impossible for most of us are made to look easy by Harrison:

Back work

A video posted by James Harrison (@jhharrison92) on

Harrison is working so hard to stay in shape so he can keep competing at the highest level. But he's surely not hiding another byproduct of his time in the gym, which is these impressive abs:

Core day!!!

A photo posted by James Harrison (@jhharrison92) on

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