LAUSR

OBJECTIVE The influence of environmental conditions, such as temperature, barometric pressure, humidity, precipitation, sunshine and cloud cover on marathon running has been widely investigated. However, the influence of such conditions on the pacing of elite marathoners has not been considered yet. The present study aimed to investigate whether environmental conditions are related to the running speed and pacing of the fastest marathoners competing in the fastest racecourse in the world, the 'Berlin Marathon'. SUBJECTS AND METHODS A total of 668,735 finishers (520,715 men and 148,020 women) competing between 1999 and 2019 in the 'Berlin Marathon' were analyzed by comparing elite and recreational runners. The associations between time-adjusted averages of the environmental conditions, the race times and running speeds were investigated. The runners were divided into performance groups consisting of recreational (all runners) and elite runners (the top 100, the top 10 and the top 3) which were separately analyzed for male and female participants. RESULTS During race days, the temperature increased while humidity decreased showing a strong negative correlation between the two variables. For all runners, the average running speed through the race showed a strong negative correlation with temperature and a strong positive correlation with the level of humidity. Faster runners experienced lower temperatures and higher humidity levels than slower runners. When the performance groups were analyzed, temperature and humidity remained correlated to a similar extent for the top 100 but dropped dramatically for the top 10 and top 3, suggesting a weaker influence. In addition, barometric pressure showed a positive correlation with running speed in the top 100 and top 3 groups. CONCLUSIONS Temperatures increased during race days while humidity decreased and both variables were negatively and significantly correlated. Faster runners experienced lower temperatures and higher humidity levels, while slower runners experienced higher temperatures and lower humidity levels which had a stronger negative impact on running speeds. Running speed was also significantly and positively correlated with barometric pressure in elite runners.