"fall halfway down the track" It means that the runner falls on the ground in the middle of the competition or the runner falls behind other runners? Sports day might be necessary at a highly-competitive independent school, but not at a village primary school. For the children who can fly like the wind, sports day cause no problem. For those who are overweight or just not good at sport, it is nightmare（噩梦）. Even for those who enjoy running but fall halfway down the track in front of the entire school and their parents, it can prove a disaster.