Sprint Resisted and Assisted Priming for Peak Performance.

Krzysztof, K, Aleksander, M, Adam, Z, and Krzysztofik, M. Sprint resisted and assisted priming for peak performance. J Strength Cond Res 37(12): 2354-2361, 2023-This study aimed to investigate resisted and assisted sprint, or a combination of both, as a conditioning activity (CA) on creatine kinase activity, biceps femoris stiffness, postactivation performance enhancement (PAPE), and priming in a sprint. Ten female sprinters (age: 20.1 ± 2.3 years, body mass: 56.4 ± 4.2 kg, body height: 171 ± 5 cm, training experience: 5.6 ± 2 years) participated. Before the warm-up, blood samples were drawn to determine creatine kinase at baseline. After the warm-up, biceps femoris stiffness was determined, and consequently, 50-m sprint time (with 0- to 20-m and 20- to50-m split time evaluation) was assessed 5 minutes before (pre-CA) and in the seventh minute after the completion of each CA (4 sets of 40 m either: 10% body mass resisted [RST]; 105% maximum velocity assisted [AST] sprint; or 2 sets of each sprint as the CA [COMB]), as well as after 48 hours of recovery. Furthermore, another blood sample was taken 48 hours later, before the warm-up, to assess changes in creatine kinase activity. A significantly higher 20-m sprint time at post-CA ( p = 0.006; ES = 0.4) and post-48 ( p = 0.011; ES = 0.59) compared with pre-CA in the RST condition was found, whereas a significantly lower sprint time was reported in post-48 compared with post-CA ( p = 0.019; ES = 0.44) in the COMB condition. However, a significantly lower 30-m flying sprint time at post-CA ( p < 0.001; ES = 0.28) and at post-48 ( p = 0.014; ES = 0.22) compared with pre-CA in the RST condition was revealed. Moreover, a significantly lower 30-m flying sprint time at post-48 compared with the pre-CA ( p = 0.007; ES = 0.7 and p = 0.003; ES = 0.77) and with the post-CA ( p = 0.019; ES = 0.61 and p = 0.009; ES = 0.68) in the AST condition and COMB was reported. Furthermore, a significantly lower 50-m sprint time at post-48 compared with pre-CA ( p = 0.015; ES = 0.51 and p = 0.011; ES = 0.64) and with post-CA ( p = 0.005; ES = 0.46 and p = 0.001; ES = 0.55) in the AST and COMB condition were found. The creatine kinase activity at post-48 during AST was significantly lower than during RST ( p = 0.028; ES = 0.73) and COMB ( p = 0.028; ES = 1.48). No significant changes were found for biceps femoris stiffness ( p = 0.085; η 2 = 0.199). The COMB and AST contributed to the improvement of the 50-m sprint time 48 hours after activation, which may be a good precompetition approach. However, during training sessions aiming to induce an acute PAPE effect and improve the 30-m flying sprint time, the best solution might be to use low-volume-resisted sprints.