At 31, I felt old. Not in the ‘I wish I was 20 again’ or ‘life’s passing me by’ type of way; quite the contrary. But within my fitness levels, or more accurately lack of them. I would make an ‘ooooff!’ noise while getting up off the sofa, or be out of breath after a last-minute dash for the train. To put this in perspective, I am a size 8 and eat a very healthy diet. But recently when I forced myself to think about exactly how much exercise I do, the answer was a big, fat zero. I run my business from my office at home, so I don’t even walk to and from work. Tragic.