The aim of the current study was to analyze men's and women's world records across the full range of running disciplines to contextualize the recent debate about the possibility of a sub-2-h marathon. The average male-female gap is currently 11.2% ± 1.0% for all running events. However, reducing the marathon time to below 2 h would produce a performance 12.9% (+1.7 SD) faster than the women's marathon record. This gap would be greater than all current world-record differences and would also require a reversal of medium- and long-term historical trends in the men's and women's record differences. We therefore conclude that based on historical trends and known differences between men's and women's performances, the current women's world record is not yet the equivalent of a sub-2-h marathon and, therefore, that an imminent sub-2-h marathon is implausible.
Keywords: evolution of performance; sex differences; world records.