A cartoon illustrating the relationship between displacement, force, and contractile energy. The same amount of energy is used to deform the springs in cases 1 and 2. For the soft spring, a small force is applied over a long distance. In the stiff spring, a large force is applied over a short distance. The work done in each case is equivalent (W₁ = W₂ = F₁Δx₁ = F₂Δx₂). Conversely, in case 3, a small force results in only a small displacement, and therefore requires less energy (W₂ < W₂).