telly drama Jamestown has told how he took drastic measures to achieve the rippling physique he displays in the show.Stuart Martin admits he was terrified when he realised he was going to be walking around in a loin cloth in front of millions of viewers as he was so out of shape.The 33-year-old, from Ayr, said: “A couple of months before we started filming, I thought, ‘I’ve got to get to the gym.’ I had been a resting actor, enjoying my life at home, and I was about 15st.“I was chatting to a