The actor said life is great after his daughter was born, reported Ace Showbiz.
"I gotta jump in and do all those sorts of things. I mean, I've even tried breastfeeding," the first-time father joked.
"It's frustrating for the baby and frankly disturbing for me... Not well is the answer. It's amazing that you can be that exhausted and that happy at the same time," he added.
Reynolds, 38, and his actress wife Blake Lively, 27, welcomed their first child together last December, two years after they got married.
The hunky actor was at the Sundance Film Festival to promote his new film, "Mississippi Grind".