Most people training for and running a marathon will have heard of'' hitting the wall' and received the advice to "avoid going out too fast at the start". Well in a study that looked at non-elite performances at the 2015 Chicago Marathon, data analyst Barry Smyth provides the data behind such sound advice.
It was found that 50% of runners who hit the wall ran their first 5km as their fastest segment of the race. However, for those who ran the first 5km as their slowest segment, they never hit the wall and on average finished 50 minutes faster than those who had started too quickly.
Possibly shades of 'The tortoise and the hare' here.
The study also showed that male runners tended to be 3 - 4 times more likely to hit the wall than women.
More details of the study can be found here