Journal of Sports Analytics 4 (2018) 229–242 229 DOI 10.3233/JSA-170205 IOS Press Fast starters and slow finishers: A large-scale data analysis of pacing at the beginning and end of the marathon for recreational runners Barry Smyth∗ Insight Centre for Data Analytics, School of Computer Science, University College Dublin, Ireland Abstract. Every year millions of people participate in big-city marathons around the world, with such events routinely attracting thousands and even tens of thousands of participants. Careful pacing is widely considered to be an important determinant of success in the marathon and, come race-day, most participants will have decided on a pacing strategy to ensure they manage their energy levels and optimise their finish-times. While researchers have examined the pacing of elite athletes, recreational runners are less well understood. We present an analysis of 1.7 million recreational runners, focusing on pacing at the start and end of the marathon, two particularly important race stages. We show how starting or finishing too quickly can result in poorer finish-times, because fast starts tend to be very fast, leading to endurance problems later, while fast finishes suggest overly cautious pacing earlier in the race. We find that women tend to pace their race more effectively than men, but they can be more cautious too, costing them minutes overall. These findings help to quantify the costs of uneven pacing at the start and end of a marathon, and may help to improve coaching and performance in endurance races. Keywords: Marathon running, pacing, recreational runners 1. Introduction project1, designed to break the two hour marathon time, albeit in a highly engineered race setting. In the There are few sporting events quite like the end Eliud Kipchoge registered an impressive 2:00:25 marathon. For many it is the iconic endurance event time, only narrowly missing the two hour target. As and yet, despite its gruelling 26.2 miles (42.195 kms), as a result the narrative around this milestone time it appeals to millions of runners every year, men and has shifted somewhat, from a discussion of “if” to women, young and old, and from all walks of life. The “when”. marathon is unique because many events see recre- Careful pacing during the marathon is widely ational athletes competing side by side with top elites. considered to influence performance, and come race- For many it is all about surviving the distance, for oth- day most participants, whether recreational or elite, ers it’s about achieving a personal best, and for a rare will have carefully considered their pacing strategy. few it is about winning, and even breaking records. Should a runner aim to run with an even pace through- Just as the 100 m sprint and mile distances have had out the race? Or is it better to plan for a faster first their landmark times (ten seconds and four minutes, half, bank time, and hope to hold on during a slower respectively) so too does the marathon, with its fabled second half (a so-called positive split)? Or, should two-hour target time. In fact, at the time of writ- runners pace more conservatively during the first half ing, Nike have recently completed their Breaking2 of the race, speed-up in the second half, and then push ∗ hard for a fast finish (a so-called negative split)? In the Corresponding author: Prof. Barry Smyth, Insight Centre past researchers have focused on the pacing patterns for Data Analytics, School of Computer Science, University College Dublin, Dublin 4, Ireland. Tel.: +353 1 716 2473; E-mail: [email protected]. 1https://en.wikipedia.org/wiki/Breaking2. 2215-020X/18/$35.00 © 2018 – IOS Press and the authors. All rights reserved This article is published online with Open Access and distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC 4.0). 230 B. Smyth / Fast starters and slow finishers of elite athletes (Abbiss and Laursen, 2008; Esteve- 2. Related work Lanao et al., 2014; Gosztyla et al., 2006; Hanley, 2013, 2015; Lara et al., 2014; Renfree and St Clair There is a growing body of work that explores Gibson, 2013; Tatem et al., 2004; Tucker et al., 2006). the various factors that influence pacing during a However, the pacing patterns of recreational run- wide range of athletic events. Indeed, with the advent ners are less well understood, notwithstanding some of cheaper and more reliable timing technologies, recent work (Barandun et al., 2012; Deaner et al., endurance races such as the marathon, and the ‘big 2014; March et al., 2011; Santos-Lozano et al., 2014). data’ that they can generate, provide new opportu- The popularity of the marathon, and the availabil- nities to capture, analyse, and better understand the ity of reasonably fine-grained timing data at many performance patterns of athletes, at all levels of train- mass-participation events, now presents a unique ing and ability. In what follows we will summarise a opportunity to explore many aspects of race perfor- representative sample of pacing research for various mance, including pacing, for recreational runners. In endurance events, for elite and recreational runners, this article we present one such study, in the form to provide a context for the work presented in this of a large-scale, multi-year, multi-race data analy- article. sis of more than 1.7 million recreational runners, Tucker et al. (2006) examined the pacing strate- focusing on pacing during the critical opening and gies of male runners in world-record performances closing stages of the race. Our main findings include for 800m, 5,000m, and 10,000m events, from 1912 to the following: 1997. They showed that the optimal pacing strategy, during such performances, differed depending on the 1. Starting or finishing too fast is associated with event duration. The 800m event saw more speed at slower overall finish-times, as partly predicted by the start (first lap) of the race, with limited evidence Denison (2007), and there is evidence of a causal of athletes increasing their speed during the remain- relationship between start pace and finish-time, in der of the event. Indeed, world-record 800m races are particular. characterised by a second lap that is typically much 2. Fast starts are injurious to finish-time perfor- slower than the first lap, supporting the notion that mance because they have a tendency to be much performance in shorter events is improved by a fast faster than most other race segments, leaving run- start, even at the cost of a slower finish. In contrast, ners with a longer remaining distance to endure, world records in the 5,000m and 10,000m events were and increasing the probability that they will go reported to be characterised by fast starts, followed on to hit the wall later in the race (Buman et al., by a period of slower running during the middle of 2008a,b, 2009; Rapoport, 2010). the race, and then a significant burst of speed in the 3. Fast finishes are also associated with slower closing stages. finish-times, because they sometimes signal cau- Physiologically, the final burst of speed suggest tious pacing earlier in the race, as if runners are athletes are able to effectively manage their reserve holding back for a final sprint. capacity during the middle section of the race, and to 4. While women may pace more effectively than draw on these reserves late in the race, to overcome men (de Koning et al., 2011; Hubble and Zhao, those factors that were responsible for the earlier 2016; Santos-Lozano et al., 2014) they may do reduction in speed. The manner in which elite ath- so too cautiously, which can cost them minutes in letes choose a sub-maximal speed at the start of terms of their overall finish-times. the race, and then optimise their pace during these longer events, is still not well understood. Of course, In the following sections we will review related it needs to be acknowledged too that world-record work on the topic of marathon pacing before describ- performances are, by definition, unlikely to be repre- ing the data used for this study, and explaining our sentative of regular race performances, even among analysis methodology and key findings in detail. We elites, and thus are not necessarily achieved with opti- believe that these findings will be of general inter- mal pacing strategies. In the present work, where the est to runners, coaches, and sports scientists alike, by focus is on recreational runners, there is a finish- quantifying the importance of careful pacing, espe- time cost for both a fast start and a fast finish in cially at the start of the marathon, while highlighting the marathon. This suggests that, compared to elites, the risks of conserving too much energy for the end recreational runners are much less adept at select- of the race. ing or maintaining optimal pacing, relative to their B. Smyth / Fast starters and slow finishers 231 training or ability, during the marathon event, as a fair basis for comparison; a woman finishing in 3 might be expected. hours can be considered to be performing at a higher In related work, Gosztyla et al. (2006) studied the level than a male runner with the same finish-time, optimal pacing strategy for 5,000m races, this time all other things being equal. To address this, Deaner for moderately trained female distance runners. The et al. (2014) focused on comparing the pacing of results, based on an analysis of 11 runners, suggest male and female recreational runners while correct- that the best performance can be achieved by run- ing for this.