# Durability of Parameters Associated With Endurance Running in Marathoners

## TL;DR

The study shows that marathon performance is linked to how well certain endurance markers resist deterioration during prolonged running.

## Contribution

The study introduces durability of lactate threshold parameters as a novel marker for predicting marathon performance.

## Key findings

- Prolonged running reduces peak oxygen uptake and lactate threshold speed.
- Durability of lactate threshold speed is significantly associated with faster marathon times.
- Running economy and fractional oxygen utilization remain unchanged after prolonged exercise.

## Abstract

Physiological markers of endurance performance include the maximal oxygen uptake (V̇O2peak), its fractional utilisation at lactate threshold (FULT), and running economy (RE), which are closely tied to the speed eliciting the lactate threshold (sLT). These parameters deteriorate during prolonged exercise, and the ability to resist such declines (i.e., durability) is now also considered a marker of marathon performance. This study investigated the durability of markers of endurance performance (V̇O2peak, FULT and RE), and whether the durability of these markers was associated with marathon performance. Eighteen participants of the 2024 London Marathon (11 males, age: 41 ± 12 years, marathon finish time: 3:17 ± 0:32 h:min) completed two separate visits to determine V̇O2peak, FULT, RE and sLT in a ‘fresh’ state (PRE) and following a 90‐min run at sLT (POST). Reductions in V̇O2peak (PRE: 56.7 ± 7.2 mL·kg−1·min−1 vs. POST: 53.4 ± 6.3 mL·kg−1·min−1, p < 0.001) and sLT (PRE: 12.8 ± 2.0 km·h−1 vs. POST: 12.1 ± 2.2 km·h−1, p < 0.001) were evident, but RE and FULT were unchanged (both p > 0.05). The percentage change in sLT between POST and PRE (r = 0.680, p < 0.01) was significantly associated with marathon performance, whereby small deteriorations of sLT were associated with faster marathon times. Prolonged running impairs key physiological markers of endurance performance, and the degree of this deterioration, that is, durability, is associated with marathon performance. Marathon runners and practitioners should consider quantifying durability to complement existing physiological markers.

Peak oxygen uptake and parameters associated with the lactate threshold are subject to deterioration following prolonged running.The durability of parameters associated with the lactate threshold, including the relative V̇O2 at lactate threshold and the speed at lactate threshold, are associated with marathon performance.Durability should be considered alongside traditional performance markers to improve physiological profiling in marathon runners.

Peak oxygen uptake and parameters associated with the lactate threshold are subject to deterioration following prolonged running.

The durability of parameters associated with the lactate threshold, including the relative V̇O2 at lactate threshold and the speed at lactate threshold, are associated with marathon performance.

Durability should be considered alongside traditional performance markers to improve physiological profiling in marathon runners.