Exploring the wall in marathon running

Abstract

The wall is an iconic feature of the marathon. If runners hit the wall, usually around the 30km (20mi) mark, their pace slows dramatically, leaving them to struggle to the finish-line. While the physiology of the wall is reasonably well understood – a critical combination of fatigue and a lack of available fuel as the body’s glycogen stores become depleted – its actual impact is less well studied. In this paper we present a large-scale data-driven study of how and when recreational marathon runners hit the wall. We do this by analysing the pacing patterns of almost 60,000 runners across more than 250 races. The main contributions are: (1) an operational definition of the wall by identifying its key pacing features; and (2) and analysis of hitting the wall for runners, based on their age, gender and ability, using this definition.