The Gulliver's Travels star, 41, admitted that if he doesn't get a good snooze he ends up just sitting with sons Samuel and Thomas in front of the TV.
He told Parade, 'The more sleep I get, the better dad I am.
'Parenting is 90 percent energy, if you don't have it, then there tend to be some lazy TV-watching days with the kids, and that ain't gettin' it done.'
He added, 'A great day with them - my sons are four and two - is an energised adventure into the world. My best piece of parenting advice? Never try to make a happy child happier.
'Just leave it alone. When you try and kick it up to another level with a scoop of ice cream or whatever, it ruins everything.'