I noticed something about Tom whilst watching his Episodes of Doctor Who. Whenever he and others are running around, the other peoples steps are Twice his, lol. There he'd be just loping along and their legs would be doing double time. It's rather amusing.
My hubby is six foot three and I'm a whopping five foot four. So I can empathize with the other actors that had to keep up with Tom.
makes me tired just thinking about it. 
However, as my hubby points out to me whenever I complain about being left behind when we walk. It is not easy for a tall person to keep stopping to wait for the short legged to keep up. Or to have to shorten their stride to match the stumper's, lol. That reminds me of a scene in one of the episodes filmed in Paris where the Doctor and, I think it was Romana, came up out of a train tunnel? Anyway, he was striding along then turned around and saw that she was well behind him. He waited for her to run and catch up to him, lol.
MCH
