Mike Bushell feels the freeze at icy swim session

Athletes often boast of taking ice baths to relieve their muscles after a tough workout, but what about actually swimming in near freezing water?

Is this invigorating exercise, or just an exercise in pain?

BBC Breakfast's Mike Bushell joined swimmers at a mid-winter training session at Tooting Bec Lido, home of the UK Cold Water Championships, to find out.