Regular Long Runs and Higher Training Volumes are Associated with Better Running Economy Durability in Performance Matched Well-Trained Male Runners.

Introduction: Running economy (RE) deteriorates during prolonged running (i.e. RE durability), although it is unknown if runners' training characteristics influence RE durability. Furthermore, the extent of the decrement in neuromuscular capabilities after running could also contribute to differences in RE durability. Therefore, this study aimed to compare RE durability during a 90 min run and the decrements in neuromuscular capabilities, between athletes that did, or did not, practice regular long runs, whilst pair-matched for performance status.

Methods: Two groups of 13 male runners were recruited as long (LDT; regular long runs ≥90 min) or short distance training runners (SDT; all runs <70 min) and matched for 10 km performance (39:10 vs 39:00 min:s; maximal oxygen uptake (V̇O2max) 56.6 vs 58.9 ml·kg-1·min-1). Participants completed preliminary assessments to determine lactate threshold (LT) and V̇O2max, then on a separate occasion, a 90 min run at LT. Respiratory gases were collected every 15 min, and isometric squat peak force and countermovement jump (CMJ) were assessed before and after the run.

Results: Changes in RE occurred earlier and were larger for SDT than LDT, reaching +6.0% vs +3.1% at 90 min, respectively (p < 0.001). Isometric squat force (-19.4 vs -12.2%; p = 0.002) and CMJ mean power (-6.6 vs +2.2%; p = 0.011) decreased more in SDT than LDT runners, however these changes were not correlated with RE durability, whilst correlations were found between RE durability and the weekly longest run (r = -0.67; p < 0.001) and training volume (r = -0.48; p = 0.0038).

Conclusions: This study is the first to demonstrate that the presence of long runs and higher training volumes positively affects RE durability and decrements in neuromuscular capability in performance-matched runners. These results provide important insights into how training characteristics may help explain differences in durability, although intervention studies are needed to confirm these cross-sectional findings.