The air-resistance to a runner

The resistance of the air to the motion of a badly stream-lined body, in which the negative pressure on the leeward side, due to eddy formation, is appreciable, may be roughly 0·6 pv2A, where v is the relative velocity, p the density of the air, and A the projected area on a plane perpendicular to the direction of motion. In a recent paper Furusawa, Hill and Parkinson (1) have examined the motion of a runner making a maximal effort over a short distance, on the assumption that the air-resistance is negligible when compared with the resistances inherent in the muscles and limbs of the runner himself. This assumption is nearly, but not strictly, true, the air-resistance to a man running in still air at maximum speed being of the order of 2 to 5 per cent, of the total resistance which his muscles have to overcome. In view of the importance of fractions of a second in Model of runner used in wind-channel experiments; spindle visible at top. sprint “records,” and of the well - known influence of a following or head-wind in diminishing or increasing the time in such races, the original treatment of the dynamics of sprint-running may be modified to take account of the air-resistance as follows.