Energetics (and kinematics) of short shuttle runs

PurposesThe energy cost of shuttle running (CnetSR), over distances of 10–20 m, was reported to increase with the shuttle speed and to decrease with the shuttle distance. The aims of this study were to assess CnetSR over a shorter distance (5 m), at different speeds, and to estimate the energy cost based on a simple kinematic analysis (CnetK).MethodsTen subjects (six basketball players, BP; four non-basketball players, NBP) performed ten shuttle runs (SR) with 30 s of passive recovery in-between, over a distance of 5 + 5 m (with a 180° change of direction); these experiments were repeated at different speeds (range 2–3.5 m s−1). The values of average (vmean) and maximal (vmax) speed during each run were determined by means of kinematic analysis and CnetK was calculated as: 0.96$$v_{ \hbox{max} }^{ 2}$$vmax2. CnetSR was calculated based on data of oxygen uptake, blood lactate concentration and distance covered.ResultsThe relationships between C (J m−1 kg−1) and v (m.s−1) are well described by CnetK (all subjects) = 11.76v − 13.09, R2 = 0.853; CnetSR (BP) = 11.94v − 12.82, R2 = 0.636; and CnetSR (NBP) = 14.09v − 14.53, R2 = 0.738. Hence CnetSR ≈ CnetK in BP, whereas CnetSR > CnetK in NBP (un-familiar with this specific motor task).DiscussionThe calculations proposed in this study allow to estimate C of short SR based on simple measures of vmax and can be utilized to develop training protocols in basketball as well as in other team sports (characterized by repeated sprints over short distances).