Have you ever wondered how at his age, James Harrison can move 330-pound offensive linemen around with relative ease? Well, the Pittsburgh Steelers linebacker has given us a clue.

Harrison, who will turn 39 on Sunday, posted a video of one of his workouts. In this one, he is seen pushing nearly 1,400 pounds.

https://www.instagram.com/p/BTjY7clgshZ/?taken-by=jhharrison92

Yikes.

If you’re an offensive lineman on Harrison’s 2017 schedule, you might want to get to the gym. Harrison may be nearly twice the age of the incoming rookies, but he can still move ungodly amounts of weight around.

We’re equal parts curious and afraid to see what he might do next.