26/11/2012 12:07 GMT | Updated 26/01/2013 05:12 GMT

EXCLUSIVE FEATURETTE: Behind The Scenes With Jason Segel On Judd Apatow's Film 'This Is 40'

Remember Paul Rudd and Leslie Mann's characters in 'Knocked Up'? The happy but frustrated pair watching on as Seth Rogen and Katherine Heigl came to grips with an unexpected pregnancy? Well, they're back.

Judd Apatow has focused his fourth film as a director on Pete and Debbie, those two supporting characters in the 2007 global hit. No sign of Rogen or Heigl this time around, but there is Jason Segel, who played Jason last time around.

Paul Rudd and Leslie Mann star in 'This is 40'

In 'This Is 40', Segel's Jason is a fledgling professional trainer who works with Debbie and her friend, Barb (played by "Bridesmaids" co-writer Annie Mumolo). The role gives Segel plenty of opportunities to land a barrage of funny one-liners, often at the expense of Mumolo. It also gives him the chance to get up close and personal with Mann, who happens to be Apatow's real-life wife.

Rudd and Mann play Pete and Debbie in this look at what happens when we hit the big 4-0

HuffPostUK Entertainment is happy to debut a new behind-the-scenes look at Segel's role. Watch the feature, 'On The Set: Bodies By Jason', above.

As well as Rudd, Mann and Segel, the film also stars Chris O'Dowd, Megan Fox, Maude Apatow, John Lithgow and Albert Brooks.

This is 40 is in UK cinemas from 14 February 2013.

Photo gallery 'This Is 40' Stills See Gallery