Bow down, puny humans, before the Mountain. While we were all pitifully struggling to hit one mile on the treadmill, the Game of Thrones actor has apparently been training to become a human tow truck. The results of these efforts can be seen in a new video that finds him pulling a 17-ton big rig with terrifying speed.

For those of us who watched actor Hafthór Björnsson lose an arm-wrestling match to the much smaller heavyweight-champion arm wrestler Devon Larratt—and thought for a split second that the Mountain isn’t as strong as he looks—well, we were wrong.

In the video, we see Björnsson huffing and puffing and pulling the giant truck down a road as a couple other men—trainers, presumably?—bark at him. According to TMZ, this video isn’t even the half of it—he did laps pulling this thing.

O.K., so this shouldn’t really come as much of a surprise. The guy is huge, as any Thrones fan can attest. Just last year he defended his title as Europe’s Strongest Man—and won for the second year in a row.

Björnsson has also competed for World’s Strongest Man: he placed third in 2012, 2013, and 2015. He even placed second in 2014. Talk about gymspiration. Let’s just hope his training rituals don’t involve too much skull-crushing.