Behavior of creatine kinase in a variable resistance session

[Purpose] The purpose of this study was to determine the behavior of creatine kinase before and after the execution of a pre-activation protocol with intra-set variable resistance in order to generate post-activation potentiation in female athletes. [Participants and Methods] Six sprint women were part of the study. The study had a quasi-experimental intra-participant design. The experimental condition included a pre-activation with intra-set variable resistance + 1 minute rest + 30-m sprint × 3. The variables were metabolic creatine kinase, total creatine kinase, and 30-m sprints. [Results] Both the experimental condition and the control condition showed an increase in creatine kinase and total creatine kinase 24 hours post-effort. Only the experimental condition showed improvement in 30-m sprints after the pre-activation with intra-set variable resistance. [Conclusion] All those sessions oriented to increasing strength levels with a pre-activation protocol through intra-set variable resistance must consider rests longer than 24 hours between sessions in order not to increase creatine kinase in female athletes significantly.