The ÖTILLÖ is a gruelling swim-run race in which competitors race over land and water.

Adventure journalist Tarquin Cooper gives a first-hand account of the lessons learnt from running in wetsuits and swimming in trainers. It’s the adventure sport that’s exploding in popularity. Forget triathlons, mud runs and so-called Obstacle Course Racing (OCR). The most highly prized t-shirt to get these days is to complete an ÖTILLÖ race.