Ryan Reynolds thought he "rode a unicorn to work" in the weeks after his daughter was born.

Ryan Reynolds

Ryan Reynolds

The 'Deadpool' actor - who has 13-month-old James with wife Blake Lively - is amazed he was able to function for the first few months after he became a father because he was so sleep deprived, and admits his exhaustion caused him to "trip".

He said: "During those first six months, it's amazing that you find a way to keep going.

"You want to trip balls? Have a kid and see what it's like to be awake for a month straight. You'll have moments where you're like, 'Did I really ride a unicorn to work? I'm pretty sure I didn't, but I don't know. Was Willie Nelson cradling my testicles this morning? It probably wasn't him, but let me check his tour schedule just to be sure.'"

The 39-year-old star is devoted to his little girl but worries some of his habits are "insane".

He told the new issue of Men's Health magazine: "I still check on her in the middle of the night and put my fingers under her nose just to make sure she's still breathing.

"Is that insane? I feel like it might be a little bit insane."

Despite his busy work schedule and family life, Ryan always finds the time to stay active.

He said: "I get depressed if I don't move. I don't necessarily need to have 400 pounds on my back in the squat rack and then take a picture of myself and send it out to my Twitter followers: 'Part of the 400-pound club today.'

" I like to hike and go biking, that kind of thing. Get outside, move my body, get some fresh air pumping through my lungs. That's my idea of a workout now."