London's Leicester Square was transformed into a running track for the premiere of new athletics film Fast Girls.
The British drama, released just weeks ahead of the Olympics, follows a female sprint relay team as they attempt to qualify for a world championship.
Its main actresses - who faced a gruelling training regime before making the film - swapped their Lycra running costumes for designer gowns as they arrived on a red carpet complete with track markings at the Odeon West End.
Leading ladies Lenora Crichlow and Lily James were joined by co-stars Phil Davis and Noel Clarke - who co-wrote the film - and real-life sporting personalities including Dame Kelly Holmes.
Lily revealed the rigorous exercise and diet routine to prepare for her role drove her to tears at times.
"It was just such a change physically and mentally at first. It was really, really hard," she admitted. "When filming wrapped it was Christmas, so I ate and I ate and I ate. My stomach was bursting at the seams."
The actress said she had more respect for real athletes since making the film - and joked that she was keen to show off her new skills at the Olympics. "I might compete, I've been thinking about it. But I'll let them have their day," she quipped.
Lenora, who plays Lily's rival on the track, said she could not stop reading the script when she first received it.
"I think it's a really fresh, unique way of telling an age-old underdog story. It's got fantastic female British leads, they're the heroes of the piece. It's a really positive way of depicting women," she added.
Fast Girls is released on June 15.