Rob Brydon says shooting his new movie 'Swimming With Men' was like ''returning to the womb''.

The 53-year-old comedian stars in the drama 'Swimming With Men' - which is an adaptation of the documentary 'Men Who Swim' - and Rob revealed that shooting the underwater scenes in the film was a strange experience.

He shared: ''There is something wonderful about swimming. Not to get too Freudian over lunch, but there's something of returning to the womb about it: the warmth, the fact it is noiseless. And so long as you get into a rhythm, you can focus on just that one thing. Reach, hold and glide ... Reach, hold and glide...''

Rob was required to do some training for his role in the new movie.

And the British star - who previously appeared in the popular sitcom 'Gavin & Stacey' - admitted the physical challenge left him feeling exhausted.

He told GQ magazine: ''One has to begin to like exercise a little more the older one gets.

''We trained for about two weeks in the pool, each day about three hours in the water. By heavens, it's exhausting. But oh, the sleeps you have after a day of physical activity. I haven't slept that well since my childhood.''

Meanwhile, Rob previously admitted that in spite of being a ''short, middle-aged Welshman with bad skin'', he never worried about having to strip off to his Speedos to shoot the film.

He said: ''I think that's a non-actors' quandary. Actors are used to all sorts of humiliating things.''