Sitting behind Steve Coogan, a 48-year-old Mancunian, and Rob Brydon, a 49-year-old Welshman, at the Sundance screening of The Trip to Italy was hilarious, as I watched the garrulous twosome chuckle and dig each other in the ribs.
The scene that they clearly found funniest related to their version of exercise as they mounted a small number of stairs and figured that was enough.
Ultimately, Michael Winterbottom's new film, a sequel to 2010's The Trip, is as much about ageing and melancholia as it is about indulging in gastronomic delicacies and travelling along the Amalfi coast.
Afterwards I asked Coogan, who is a household name in the UK for his dowdy Alan Partridge character, if they managed to exercise away from the filming.
"Er, no. We tried to run a bit sometimes. I asked Rob if he'd done any push-ups in the morning but we just gave up the ghost after a while and ate the food and talked about stuff."
Brydon however admits he deliberately ate less because he'd piled on the kilos while making The Trip. (Though he notes, in his Welsh working-class way, that he "had a stuffed onion that I was very happy with".)
That movie had taken the illustrious pair, who had developed a strong chemistry on Winterbottom's unexpected hit, Tristram Shandy: A Cock and Bull Story, to the Lake District in England. As with The Trip, their Italian jaunt has been filmed in six parts for BBC television before being edited into a feature film for cinematic release.
"The film is generally about their relationship and the journey as much as the meals, and the first one was more about the meals," Winterbottom notes. "With both films we took out many of the British references that people outside the UK won't get."
Not that the prolific director exerts too much control over his subjects, who were loosely told to imagine themselves as romantic heroes such as Byron and Shelley.
"The cultural references tend to be English, so they are foreigners in a strange land," Coogan notes. "They don't really get to know the real Italy."
Are the characters different from their real selves? "Not a lot," he notes dryly.
An accomplished writer who was Oscar-nominated as co-screenwriter of Philomena, Coogan largely made it up as he went along.
"Michael had a sort of framework of roughly what we would talk about. We'd go off on tangents talking about Batman, doing impersonations and other stuff that wasn't on the page, then Michael would say to do more.
"So long as the story was going to end up with me reconciling myself with my son, how we got there was sort of up to us, really. There was not really a script at all.
"But when there is a script with Michael I give up learning it because in the morning he looks at it and goes 'I'm not really interested in this. Let's do something else'. Then we improvise anyway. It's all pretty much improvised."
The film screams that Coogan and Brydon had enormous fun during the month-long shoot. "It was an amazing experience. We were at some of the most beautiful places in the world. There was spellbinding scenery wherever we went and we diminished it all by talking crap."
During the day, particularly over lunch, the pressure was on to "press each others' buttons" in front of the cameras. In the evenings the pair, who rarely see each other away from their movies, had a more civilised private dinner together.
"We were staying in the same hotel and it was a lot nicer," Coogan recalls. "We talked about each other's families and both of us cried on different occasions. We had a nicer time than on the previous film."
Fans would come up to them too. "It's that nice kind of thing. People love it. They don't think it's rubbish, so obviously that's great."
Will there be a third trip? "If Richard Linklater can do a trilogy, why can't we?"
Brydon: "I don't know where we'd do it or if we'd do it. But Australia is lovely at this time of the year!" Now that's an idea.