Running mechanics during the world's most challenging mountain ultramarathon

Francis Degache, Jean Benoît Morin, Lukas Oehen, Kenny Guex, Guido Giardini, Federico Schena, Guillaume Y. Millet, Grégoire P. Millet

Research output: Contribution to journalArticlepeer-review


The aim of study was to examine the effects of the world's most challenging mountain ultramarathon (Tor des Géants [TdG]) on running mechanics. Mechanical measurements were undertaken in male runners (n = 16) and a control group (n = 8) before (PRE), during (MID), and after (POST) the TdG. Contact (tc) and aerial (ta) times, step frequency (f), and running velocity (v) were sampled. Spring-mass parameters of peak vertical ground-reaction force (Fmax), vertical downward displacement of the center of mass (Δz), leg-length change (ΔL), and vertical (kvert) and leg (kleg) stiffness were computed. Signifcant decreases were observed in runners between PRE and MID for ta (P <.001), Fmax (P <.001), Δz (P <.05), and kleg (P <.01). In contrast, f signifcantly increased (P <.05) between PRE and MID-TdG. No further changes were observed at POST for any of those variables, with the exception of kleg, which went back to PRE. During the TdG, experienced runners modifed their running pattern and spring-mass behavior mainly during the frst half. The current results suggest that these mechanical changes aim at minimizing the pain occurring in lower limbs mainly during the eccentric phases. One cannot rule out that this switch to a "safer" technique may also aim to anticipate further damages.

Original languageEnglish
Pages (from-to)608-614
Number of pages7
JournalInternational Journal of Sports Physiology and Performance
Issue number5
Publication statusPublished - Jul 1 2016


  • Anticipatory adaptations
  • Safer technique
  • Sleep deprivation
  • Spring-mass behavior

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine


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