A teacher at Bermondsey’s Boutcher Church of England Primary School took bronze at the 2016 Triathlon World Championships, after students helped fundraise her trip.
Hannah Ewens, from Peckham, started doing triathlons two years ago and has since trained every week alongside teaching.
The training paid off last month at the prestigious competition, with her coming third in the Amateur Sprint, 25-29 age group.
Hannah, 26, said: “When I got out to Mexico I did a video link with my reception class. It was good because we were doing stuff about the Olympics and different sports that different countries do.
“Last year they did a couple of fundraising events to help me get to Mexico, like paying £2 to wear sports kit.
“I have an ambition to keep going to get as good as I can while teaching. I love my job. I’ve been teaching here for three years.
“I don’t actually remember it [the triathlon]. I had heat stroke and went onto a drip straight after. What happened to Jonathan Brownlee happened to me but I managed to finish on my own! I finished in one hour and six minutes.
“The event was a 750m swim in the sea, a 20k bike and 5k run. The run is my favourite. I got back on a Wednesday and came straight here [to the school]. I want to get as good as I can but still teach. I think I can manage both.”
The school raised £1,720 to help Hannah get to Mexico, where she shared updates with the children throughout.
The competition was thrown into the spotlight this year after Jonathan Brownlee, one of the Brownlee Brothers, suffered severe dehydration just before finishing first, leading to his brother, Alistair, picking him up and pushing him over the finish line to come in third.