SARAH RAINEY joins the die-hards who go swimming in Hyde Park every morning - so is it really good for you?

SARAH RAINEY: My toes are numb, my legs are turning an alarming shade of purple - and I've got goosebumps in places I didn't know I had. It's just gone 7.30 am on one of the coldest days of the year (-14C, to be exact) - and I'm standing on the snowy banks of the Serpentine in London 's Hyde Park, wearing a swimsuit. Shivering doesn't come close to describing the strange way my body is convulsing as I tentatively dip one foot in the icy water, followed by the other. But while the rest of us shivered under our duvets, there were groups of hardy swimmers - all perfectly sane, rational people - doing just that. The UK's oldest swimming club, the Serpentine Swimming Club, based in Hyde Park, has never seen such a busy week. The snow and super sub-zero temperatures just add to the fun, say members. But is it fun? I'll get back to you on that.