Halfway up a long hill in the Kenyan wilderness, a photographer pointed towards the bush. Just 20 metres (66 feet) away, a hyena was running through the undergrowth, chasing its prey. It was exhilarating – and a little terrifying. I was taking part in Beyond the Ultimate’s For Rangers Ultra, a five-day, 230km (143-mile) race through five Kenyan wildlife conservancies, where encounters like this were all part of the unique experience. Armed rangers were stationed around 300 metres apart along the...