Figure 5. Plot (a) shows the effect of run-up velocity on the energy change of the athlete during the take-off phase (∆ = – ), the energy gain of the athlete due to muscular work performed during the pole support phase of the vault (∆ = – ), and the total energy gain of the athlete during the vault (∆ = ∆ + ∆ = – ). Plot (b) shows the effect of run-up velocity on the energy loss of the athlete during the pole bending phase (∆ = – ) and the energy gain of the athlete during the pole recoiling phase (∆ = – ).