%0 Journal Article
%T Running at altitude: the 100-m dash
%+ Università degli Studi di Udine - University of Udine [Italie]
%+ Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM )
%+ French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA7370) (SEP (EA7370))
%+ Department of Physiopatology and Transplantation, University of Milan (DEPT)
%A Di Prampero, Pietro
%A Osgnach, Cristian
%A Morin, Jean-Benoît
%A Slawinski, Jean
%A Pavei, Gaspare
%A Samozino, Pierre
%< avec comité de lecture
%@ 1439-6319
%J European Journal of Applied Physiology
%I Springer Verlag
%V 121
%N 10
%P 2837-2848
%8 2021-10
%D 2021
%R 10.1007/s00421-021-04752-y
%K Sprint
%K Acceleration
%K Altitude
%K Mechanical power
%K Air resistance
%Z Life Sciences [q-bio]
%Z Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph]
%Z Humanities and Social Sciences/Sport/Sports
%Z Humanities and Social Sciences/Sport/Sport physiologyJournal articles
%X Purpose
Theoretical 100-m performance times (t100-m) of a top athlete at Mexico-City (2250 m a.s.l.), Alto-Irpavi (Bolivia) (3340 m a.s.l.) and in a science-fiction scenario “in vacuo” were estimated assuming that at the onset of the run: (i) the velocity (v) increases exponentially with time; hence (ii) the forward acceleration (af) decreases linearly with v, iii) its time constant (τ) being the ratio between vmax (for af = 0) and af max (for v = 0).
Methods
The overall forward force per unit of mass (Ftot), sum of af and of the air resistance (Fa = k v2, where k = 0.0037 J·s2·kg−1·m−3), was estimated from the relationship between af and v during Usain Bolt’s extant world record. Assuming that Ftot is unchanged since the decrease of k at altitude is known, the relationships between af and v were obtained subtracting the appropriate Fa values from Ftot, thus allowing us to estimate in the three conditions considered vmax, τ, and t100-m. These were also obtained from the relationship between mechanical power and speed, assuming an unchanged mechanical power at the end of the run (when af ≈ 0), regardless of altitude.
Results
The resulting t100-m amounted to 9.515, 9.474, and 9.114 s, and to 9.474, 9.410, and 8.981 s, respectively, as compared to 9.612 s at sea level.
Conclusions
Neglecting science-fiction scenarios, t100-m of a world-class athlete can be expected to undergo a reduction of 1.01 to 1.44% at Mexico-City and of 1.44 to 2.10%, at Alto-Irpavi.
%G English
%L hal-04067772
%U https://insep.hal.science//hal-04067772
%~ SHS
%~ UNIV-ST-ETIENNE
%~ UNIV-SAVOIE
%~ UNIV-LYON1
%~ INSEP
%~ LIBM
%~ UDL
%~ UNIV-LYON