Is there an effect of the order of realization of sprint and endurance for intermittent test?

The aim of this study was to examine whether the sequence in which sprint (S) and endurance (E) races are executed has effects on performance and physiological responses in children. Seventy-seven male pubescent students aged 18 ± 3 years performed two protocols (P1 and P2) consisting in 2000m walking to warm-up (W), followed by S on 100m and E on 1000m; (P1= W + S + E and P2 = W + E + S). Heart rate (HR) was monitored continuously. Systolic blood pressure (SBP) and skin temperature (Tsk) were measured at the beginning and at the end of protocol. Two resting electrocardiogram (ECG) were registered before and after protocols. Performances of W (1183 ± 119 vs 1186 ± 130 s); E (389 ± 59 vs 355 ± 104s); S (21 ± 3 vs 21 ± 5s) during P1 and P2 respectively were similar. HR, Tsk were lower after E than S (p <0.01). SBP were higher after E than S (p <0.01). No significant differences were found in ECG between P1 and P2. In conclusion, the sequence in which S and E are executed induces different physiological responses and has no effect on physical performance in children.