%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