This is the hilarious moment a gym-goer photobombed his friend's workout video while he was filming himself doing bicep curls.

Gio Bautista was trying to record his exercise sets when his mischievous friend, Wendell Villegas, suddenly appeared in the frame at Project Fit gym in Batangas, the Philippines.

Footage shows Gio placing his phone on the ground before walking towards a barbell to begin his routine on July 18.

Moments later, Wendell, who was performing a back hyperextension nearby, leaned up mid-crunch with his arms crossed on his chest and made a cheeky appearance in the background beneath the camera.

After completing three reps, he burst into laughter and slid off the machine, eventually rolling safely onto the floor.

Gio said: 'Wendell knew I was filming, and he intentionally interrupted me just to annoy me.'