Fig. 5. The predicted net cost of running (E_run) and walking (E_walk) using the new allometric equation of the net cost of running (Eqn 2; solid line) and the new allometric equation of the net cost of walking (Eqn 4; broken line). The point where these relationships intersect (20 kg) represents the theoretical mass where the net cost of walking and running are equivalent. Above this mass, the net cost of walking is predicted to be greater than the net cost of running, and below this mass the opposite is predicted.