Over the past two decades, Steve Backshall has pushed himself to his limits in every high-octane environment that you can imagine, from scaling sheer mountains in Venezuela and wading through Argentinian swamps to descending into desert canyons in Oman. When we caught up, the Deadly 60 host (which airs on BBC Earth in the UK) is fresh from a fortnight spent thundering down violent white-water rapids on Russia’s Kamchatka Peninsula.

The trip was as grueling as it gets. “Occasionally, you had to put your boat on your back and hike with it,” he says. “One day, we spent eight hours thrashing through dense bush. Then, you had to get back in and tackle the rapids. It was brutal.”

Bodyweight exercises form the foundations of Backshall’s training, which is tailored to every expedition. To prepare for Kamchatka, he alternated steady-state kayaking with intense HIIT. “I had a good deal of power work—lots of plyometrics, calisthenics, tossing big tyres,” he says. “It’s all geared towards having that explosiveness available when you need it. At my age, it’s one of the first things that tends to go, if you don’t work on it.”