Why now? A physiological perspective on the first official sub-2-hour marathon.

The first official sub-2-hour marathon provides a unique real-world case for re-examining the determinants of elite marathon performance. This Perspective argues that the key scientific issue is not whether human physiology can theoretically support sub-2-hour running, but how physiological capacity can be preserved and expressed under late-race fatigue. Sabastian Sawe's 1:59:30 performance was marked by a 59:01 second half and, based on available split data, a 27:36 segment from 30 to 40 km, indicating late-race acceleration rather than simple pace maintenance. The wider front-group pattern, with Sawe, Kejelcha, and Kiplimo all completing the second half in approximately 60 min or faster, suggests that the barrier fell within a collective performance environment rather than through an isolated individual effort. The core interpretation is that the post-sub-2 era should be studied through fatigue resistance and race execution: the ability to preserve running economy, substrate availability, neuromuscular control, perceptual regulation, and tactical commitment after prolonged marathon-specific stress. High-rate carbohydrate delivery, gastrointestinal training, advanced footwear technology, buffering strategies, competitive proximity, and performance support systems are therefore interpreted not as separate explanations, but as interacting supports for late-race capacity expression. Advanced footwear likely contributed by reducing energetic cost and amplifying the expression of that capacity, although responses to such technology are variable and independent data on the exact shoe model remain limited. The first official sub-2-hour marathon should therefore be viewed neither as a purely physiological achievement nor as a technology-driven outcome, but as an extraordinary human performance expressed through an increasingly integrated athlete-technology-performance system.