Author(s): WALT, M., WALT, M., COMINO, P., LE GOFF, J.M., CASADO, A. , Institution: UNIVERSITY OF LAUSANNE, Country: SWITZERLAND, Abstract-ID: 1999

INTRODUCTION:
The Power Law (PL) model predicts middle-distance performance more accurately than Critical Speed model [1] from speed (m/s, S) and endurance (E) parameters but assumes these remain constant during exercise, contradicting evidence that capacity deteriorates with time and intensity [2]. Durability, the rate of capacities decline [3], has been studied primarily in long-duration exercise, leaving middle-distance racing dynamics unexplored. Understanding real-time speed capacity (S) depletion would reveal how tactical decisions interact with physiological limits to determine success. This study applied a fatigue-integrated Power Law framework (PLf) [4] to quantify section-by-section speed capacity decline and examined how speed capacity depletion, risk-taking, and competitive context interact to determine performance.
METHODS:
Official 100 m section times from 1,024 male and female Diamond League (DL) and Major Championships (MC) held between 2021–2025 (n=498 unique athletes) were analyzed. The PLf model tracked progressive decline in maximal speed capacity (S) across each 100 m section and calculated a risk ratio reflecting how closely athletes operated (v) relative to their current speed capacity (S). Linear mixed-effects models examined speed durability and risk-taking determinants across competition rounds, events, and sexes. Logistic regression determined associations between speed/durability variables and Top-3 finishing positions, with effect sizes reported as odds ratios (OR).
RESULTS:
Maximal speed capacity declined 30% on average, with high individual variability (0.65–80.78%). Higher risk-taking strongly accelerated speed capacity depletion (p<.001), providing a measurable signature of accumulating homeostatic disturbance during racing. Competition context modulated these dynamics: speed depletion was attenuated in MC heats and semi-finals compared with DL (p<.001), whereas high-risk exposure in finals produced steeper declines (p<.01). Risk expression differed by event, being front-loaded in the 800 m and emerging later in the 1500 m. Performance determinants were event- and sex-specific: maximal speed capacity predicted success in the 800 m (males: OR=1.35, p<.001; females: OR=1.37, p<.001), whereas speed durability became critical in the male 1500 m (male: OR=1.25, p<.01; female: n.s.), alongside strategic positioning (males: OR=1.55, p<.001; females: OR=1.97, p<.001).
CONCLUSION:
Elite middle-distance racing reflects the interaction between speed capacity, durability, and risk regulation. The PLf framework provides the first quantitative measure of speed durability in real-time racing, revealing that success depends not just on physiological capacity but on how athletes regulate depletion through risk-taking. These findings enable individualized training strategies to enhance fatigue resistance at 800–1500 m race-specific intensities and athlete profiling based on durability signatures.
[1] Walt et al.,2025
[2] Jones,2024
[3] Meixner et al.,2025
[4] Drake et al.,2024