Skin Suit Aerodynamics in Speed Skating

Performances analysis in sports is complex since many factors linked together contribute to the final result thus a quantification of the effects of different suits on speed skating performances just with field measurements is a difficult task. In fact, field measurements and competition results do not clearly show the effect of using different suits. Industries and Olympic committees have then been pushed to increase the number of laboratory tests on materials, apparels and equipments in order quantify the effects of different textiles on skating suits. In some sports like cycling and speed skating the speed is entirely determined by the equivalence between external power and the power lost both by frictional losses and in order to increase the speed ((

Di Prampero et al 1979a

) and (

Ingen-Schenau 1982

)). Forces acting against the athlete and power dissipated are related with the equation:

1

$$ P = FV $$

where

F

is Force and

V

is velocity. Drag, in these sports, is the most important among the frictional losses. In cycling and speed skating, when the athlete reach a constant speed, D is about 80% of the total force while the frictional force is only about 20%. Drag acting on the athletes has been often represented as:

2

$$ D = \frac{1} {2}A_p C_p \rho V^2 = KV^2 $$

K has been considered as constant both in cycling

(Di Prampero et al. 1979b)

, and speed skating (

Di Prampero et al 1979a

).