Creatine kinase as a contextual biomarker of functional recovery after exercise, training and competition in athletes: protocol for a scoping review

Protocol (version 1.0) for a scoping review that will map temporally anchored responses of circulating creatine kinase (CK) and objective functional performance after exercise, training and competition in athletes and habitually trained sport participants. The review follows JBI methodological guidance for scoping reviews and will be reported according to PRISMA-ScR, with the search reported according to PRISMA-S. Eligibility follows the Population–Concept–Context framework. PubMed/MEDLINE, SciELO and OpenAlex will be searched from inception to the date of execution with the strings fixed in this protocol, followed by backward citation searching. Two reviewers will screen and select records independently, with a third reviewer adjudicating disagreements. Charted data will be synthesised descriptively by post-exposure window and CK–function pattern (concordant, discordant, inverse-discordant, joint recovery), without pooling or inferential testing. An earlier, unregistered version of this review identified 80 reports; its original search strings were not retained. This protocol restarts the review from the search stage. The 80 previously identified reports serve as a benchmark for search sensitivity and are screened under the same criteria as every other record, with no guaranteed inclusion.