David Beckham has attempted to outdo his friend Guy Ritchie in the 22 Push-Up Challenge by sharing his effortless workout at 44,000ft.
The retired footballer accepted Guy's nomination for the latest social media craze, #22pushups, which challenges people to do 22 press-ups for 22 days to raise awareness of suicide among military veterans.
In response to his film director friend, who joked that he was "roping in the football star", 41-year-old David completed his first video in the aisle of an aeroplane.
Guy, 48, increased the difficulty of his own workout by completing the push-ups with his daughter Rivka on his back.
But David also struck a more serious note, explaining that his video was about more than joking around with his friend.
"This isn't one of his daily routines where he likes to teach u a lesson and beat you it's for a very good reason," he wrote.
"22 service men kill themselves post conflict... 22 a day, basically 1 an hour."
Other stars who have embraced the challenge so far include actors Jason Statham, Chris Pratt, Chris Evans, Dwayne Johnson, Anna Faris and John Krasinski.
The craze follows in the footsteps of the Ice Bucket Challenge, which saw social media users and celebrities across the world gritting their teeth against ice-cold water to raise awareness of motor neurone disease.
The viral campaign raised millions, leading to a scientific breakthrough.
David has tagged Justin Theroux and his own 17-year-old son Brooklyn, nominating them to begin the challenge.