Channing Tatum told Jimmy Fallon on The Tonight Show Wednesday that he put on "a nice 10 lbs." at the beginning of the COVID-19 pandemic before buckling down with his health and fitness

Channing Tatum isn't exactly known for not being in shape, but he insists he feels like "a completely new person" in terms of his fitness these days.

During a Wednesday appearance on The Tonight Show to promote his first children's book, The One and Only Sparkella, out now, the 41-year-old actor told host Jimmy Fallon that his transformation during the COVID-19 pandemic didn't come right away.

"For the first week or two weeks, I definitely was just drinking beers and riding dirt bikes but I was like, 'I can't do this for two months. This is bad,' " said Tatum.

The Magic Mike star went on to say he and a friend "just went really, really hard" after that, in terms of "training every day."

"And it was great — I mean, I came out a completely new person," he said.

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Channing Tatum on Getting in Shape amid COVID Pandemic: 'I Came Out a Completely New Person'
Channing Tatum
| Credit: NBC

"How big did you get drinking beers and riding dirt bikes? Fallon, 46, asked his guest.

"Pretty fat. I would say, you know, college 10 — a nice 10 lbs. And then I took it off," Tatum said.

The host then held up a black-and-white photo of Tatum that the actor had previously shared on Instagram back in September: a shirtless selfie showing off his fit frame.

"It's like looking in a mirror," Fallon joked.

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Fallon went on to note that Tatum got in shape for his upcoming movie Dog, in which he is set to star and also make his directorial debut.

As of December, he was also in final talks to appear alongside Sandra Bullock in the action-lacked romantic comedy The Lost City of D.

The latter film's plot follows a romance novelist (Bullock, 56) who is dreading going on a book tour with the steamy cover model (Tatum) of her latest work. Things get much worse when a kidnapping attempt sweeps them both into an adventure, where the two eventually fall for each other under very dangerous circumstances.

Ryan Reynolds was previously attached to Tatum's role. Back in October, Variety reported that Reynolds, 44, might be reunited with Bullock for the action rom-com. (The two last starred together in the 2009 comedy The Proposal.)