Whenever the subject of performance-enhancing drugs arises, I am drawn to something the American memoirist and poet Robin Magowan wrote in the late 1970s. “As sports fans we prefer to dream about angels on wheels, somehow immune to the uppers and downers of our own pill-popping society.” Alas, if you followed the build-up to Anthony Joshua’s fight at the O2 arena last night, there were no angels.