Dea and Kevin Martis with their son Liam, immediately after Dea and Kevin performed their aerial act. Photographer Nick Warner said: ‘I have returned persistently to the Hippodrome to photograph backstage at Britain’s only remaining circus building. During one summer season I asked performers to stand for portraits immediately after they finished their act, as they came off stage. My intention here was to capture the exhaustion of an artist performing two shows a day for weeks at a time