The Analysis of Elite Marathon Pacing Strategy and Performance in the Doha 2019 IAAF World Championship Female Marathon: The Effect of Extreme Hot Conditions

Introduction. The IAAF World Championships female marathon in Doha 2019 had an attrition rate of over 41% (68 entrants to 40 finishers), compared to the 14% attrition (91 entrants to 78 finishers) at the previous event in London 2017, which had a significantly faster winning time. The obvious difference in environmental conditions, potentially dictated the difference in performance. The extreme, hot conditions in Doha (32°C and 74% humidity), greatly contrasted those in London (19°C and 56% humidity). It is yet to be established if this contributed to impaired performance or if sub-optimal pacing strategy or inherent physical characteristics, (e.g., body surface area, VO2max, etc.) explain this. Method. Secondary public data were accessed for all female competitors in both races. Separate analyses of hot vs temperate marathon pacing (5km splits) and performance (common and uncommon of both races), hot marathon pacing (all finishers split into four groups; n=10 per group), hot marathon finishers vs non finishers (restricted to 10km distance) and predictors of marathon pacing in the heat were conducted. Data were compared using repeated measures ANOVA and multiple stepwise regression (0.05 alpha level). Results. Five kilometre mean split time in Doha (00:20:17 ± 00:1:55) was significantly slower than London (00:19:30 ± 00:01:35) at all 5km splits (p=0.00). Split times of finisher and non-finisher groups at 5km (p=0.768) and 10km (p=0.239) were not significantly different. World Ranking significantly predicted 61.2% of the variance in average pace in Doha (p=0.00 and adjusted r2= 0.612). Discussion. The extreme environmental conditions in the Doha 2019 World Championships resulted in slower times when compared to London 2017, a temperate environment. Athletes who finished outside of the top 10 selected poor pacing strategies, specifically those in Group 2 who followed the same even pacing strategy as Group 1 until this became unsustainable (at 25km). Non-finishers ran the first 10km at the same pace as finishers, suggesting they set off with an early aggressive pace, that was unsustainable. Inherent physical characteristics, combined with competitive experience (i.e., World Ranking) predict performance in the heat.