Running backs over 30 years old tend to get a bad rap in the NFL. Many coaches, fans and analysts believe that once a back turns 30, it’s only downhill from there to the end of their careers. Soon-to-be 32-year-old Minnesota Vikings running back Adrian Peterson is out to prove this wrong.

RELATED: Watch Retired NFL Fullback Heath Evans Bang Out 40 Reps of 225 Pounds on the Bench Press

Peterson did not have a successful season last year. During Week 2 against the Green Bay Packers, he tore his meniscus. He finished the season with 72 yards and no touchdowns. But the former NFL MVP knows how to bounce back from an injury, and he will try to do it once again.

To prove that his career and body are not in decline, the 7-time Pro Bowler showed us all how he’s been grinding in the gym this offseason.

Job 8:7 Your beginnings will seem humble, so prosperous will your future be. My mindset pic.twitter.com/YPJdRycu92

— Adrian Peterson (@AdrianPeterson) March 1, 2017

Instead of lowering the bar to his chest during the Bench Press, Peterson stops when his arms hit 90 degrees. This means he could be aiming to strengthen the top part of the rep or he is focusing more on his triceps than his chest. Regardless, pumping out 20 reps of 225 without a warm-up is impressive.

RELATED: Johnny Manziel Deadlifts 400+ Pounds, Proves His Comeback is Legit

The 4-time All-Pro then works on his explosiveness with Weighted Box Jumps and Hill Jumps. It seems that the Vikings are not planning to pick up Peterson’s 2017 contract option, which means he will become a unrestricted free agent.