It is that time of year when many a New Year’s resolution takes a back seat in favour of the more enticing of life’s activities, especially in London. But with the spring/summer season fast approaching, toning those thighs and honing those abs needs to be top of the agenda. And there really is no excuse. London has plenty more to offer than run of the mill gyms, riverside running and sweaty yoga. From cycling underwater to studio volleyball and one-on-one lean and mean pilates, get...