What is it? A weird version of Professor Burp’s Bubbleworks in which you’re pummelled with the constant threat of death.

How much does it cost? Lee Valley White Water Centre in London, which hosted the 2012 Olympic rafting events, charges from £35 per person for a session, which includes kit, safety briefing and instructor.

What does it promise? A moderate cardio workout – expect to burn up to 350 calories an hour – that utilises your upper body and core while perhaps boosting your self-esteem and helping you bond with others.

What’s it actually like? Frightening. You’re handed an oar, perched on the side of an inflatable boat alongside eight total strangers (in my case, at least), and expected to maintain basic coordination while you drop down what seems like an endless succession of ridges and get blasted by an infinite number of giant waves. Slowly but surely, you learn to place your trust in your team-mates. And then, inevitably, it all goes wrong: the boat flips, everything goes dark, and you’re thrust through the remaining ridges and waves on your back. Weirdly, this was the most exciting part of the session, and not at all scary. Either this means I had a good working understanding of the course’s safety procedures, or that my heart is black and I welcome the prospect of death with open arms. Fingers crossed it’s the former.

Best and worst bit The worst bit is inevitably the safety briefing, where the instructor lists all the horrible things that could happen to you. The best bit is when the horrible things actually do happen. Who knew almost drowning could be so exhilarating?

Is it worth it? Absolutely.