House of the Dragon Star James Norton, 40, Shares His Cold-Water Rule for Building Lasting Fitness

James Norton has now completed the London Marathon, but when he joined us on the Built For Life podcast, the actor was still a few weeks out from the start line and deep in the trenches of marathon training. That wasn't the only physical challenge on his plate. Norton has also entered the Game of Thrones universe, starring as Ormund Hightower in the third season of House of the Dragon – which, as physical challenges go, sounds exactly as medieval as you'd imagine. 'Lots of armour and swords,' Norton told us. 'Doing those fight sequences with that amount of armour on, it's brutal.' Even with everything stripped down and made as light as possible, he said, 'it's so heavy, your lower back blows up... having to do these fight sequences over and over is brutal, man.' But while swords, armour and medieval battle scenes are one thing, Norton's marathon training forced him to rethink a very different kind of physical ritual: cold water. 'I'm a real advocate of cold water,' Norton said. 'I do that every day.' Sauna has also become part of the ritual. 'Sauna I've got addicted to,' he admitted. But balancing both with marathon training proved 'interesting'. The issue? Norton assumed taking the plunge immediately after every run would be 'brilliant every time'. It turns out, not quite. 'That's actually not the case,' he said. 'You can't go cold before a run because it tightens everything up.' More importantly, he has had to rethink his post-run routine because, as he put it, 'on those tempo days, you're meant to just let your body sit in that inflammation for a little bit.' That might sound counterintuitive, especially when cold plunges are often sold as a shortcut to better recovery. But Norton has landed on the more nuanced view: cold can make you feel better, but feeling better immediately isn't always the same as adapting better. So, during marathon training, he tried to resist the thing he wanted most. 'What I'm trying to do now is leave it two hours before I get into the cold,' he said. 'Especially as the weather gets hotter, there's nothing I want more than to get cold quickly after the run.' We never thought we'd be writing about the discipline and willpower required to stay out of an ice bath, but Westeros' newest addition is clearly cut from a different cloth. What Does the Science Say? He's not wrong. The science is nuanced, particularly for runners. Cold-water immersion doesn't appear to blunt classic endurance adaptations in quite the same way it can interfere with strength and muscle growth. But running isn't just an aerobic pursuit; it's also a repeated impact stress on muscles, tendons and connective tissue. After hard or long runs, some of that soreness and inflammation forms part of the signal that tells the body to repair, remodel and become more resilient. Cold water can be useful if you need to feel fresher quickly or perform again the following day, but using it immediately after every session may not always be the wisest move if your goal is long-term adaptation. The Takeaway Ice baths aren't bad. But sometimes the most productive recovery strategy is simply giving your body a little time to do its own thing – it's pretty good at it, after all.