The athlete known for playing The Mountain on “Game of Thrones” is looking considerably less mountainous these days.

In before-and-after photos that Hafþór Björnsson — who played Gregor Clegane, a.k.a. The Mountain on the HBO hit — shared on Instagram, he reveals he’s lost a whopping 110 pounds, altering his weight from a massive 451 pounds down to a still-massive 341.

In his post, Björnsson links to a video he posted on YouTube, taking viewers through his daily diet and exercise regime.

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Björnsson, 32, retired from strongman competitions and is now training to become a boxer.

“Feeling good, feeling healthy,” he says in the video. “I think I’m doing everything I can to push myself to the limits.”

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