Everyone likes to laugh at the big lummoxes lumbering round the 1,500m at the end of the decathlon, but these people are running 1,500m at 3km/min pace (the max setting on most treadmills – a speed I can just about manage for about 30 seconds at a flat-out sprint) after having done nine other events to elite standard. It’s an absolutely astonishing piece of athleticism, endurance and sheer will.