Version of recordNarrative, scoping or critical review
Effects of Weight-Cutting Practices on Sleep, Recovery, and Injury in Combat Sports
A Scoping Review
Adrian Kużdżał, Oleg Bilianskyi, Zbigniew Wroński, Grzegorz Magoń, Gracjan Olaniszyn, Magdalena Hagner-Derengowska, Anna Michalska. 2025. Journal of Functional Morphology and Kinesiology.
Published in Journal of Functional Morphology and Kinesiology, a peer-reviewed journal
DOIhttps://doi.org/10.3390/jfmk10030319
Read the full text at PubMed CentralPDF filesPubMed 40843850
The medical question
What is known about how cutting weight affects a fighter’s sleep, recovery and risk of injury?
The Fight Medicine Research Institute uses this evidence to frame questions about recovery, injury and sleep around a weight cut. The review’s small and varied set of studies, most of them rated at high or serious risk of bias, determines which questions it can inform.
Summary
A scoping review of 17 studies links rapid weight loss in combat sports with higher markers of muscle damage, more fatigue and higher injury rates, with sleep measured in only one study.
What the work reports
- The authors searched PubMed, Scopus and Web of Science on 20 May 2025 for studies of combat sport athletes who cut weight and had sleep, recovery or injury measured. Of 2,784 records, 17 studies were included; the protocol was registered on the Open Science Framework.
- Creatine kinase, a blood marker of muscle damage, rose after rapid weight loss in the studies that reported it, perceived fatigue rose in most, cortisol results were mixed, and the one study of sleep quality recorded a small change in score, from 5.15 to 5.52, which the review describes as no significant change. In one cohort of taekwondo athletes, injury rates during weight-loss periods were 22.71 per 1,000 athletic exposures in males and 45.62 in females, against 10.86 and 17.64 in normal training.
- The authors conclude that rapid weight loss may impair recovery and raise injury risk, with possible mild sleep disruption, and that small samples, differing weight-loss protocols and a high risk of bias limit firm conclusions.
Limits to keep in mind
- The review rated four of the five randomized studies at high risk of bias and 11 of the 12 non-randomized studies at serious risk.
- The authors state that the studies differed too much in weight-loss methods, athletes and sports for a meta-analysis, and that studies without a comparison group cannot separate the effect of weight loss from the stress of competition.
- Sleep was measured in one study and injury in two, and one study included only women.
Source issues recorded
- The article includes 17 studies. Its text counts 13 male-only studies, 1 female-only study, 3 mixed-sex studies and 1 that did not report sex, which adds up to 18, and its evidence gap map section gives percentages that correspond to 20 studies (for example, 14 studies as 70%). This record uses the count of 17 given in the study selection results and in Table 1 of the article.
Publication status and notices
Published in Journal of Functional Morphology and Kinesiology, a peer-reviewed journal. Scoping review in Journal of Functional Morphology and Kinesiology.
Form of this work: Version of record. The version of record is the final article as issued by its publisher.
No correction or retraction notice was found in Crossref or Europe PMC when this record was checked.
Fight Medicine Research Institute contribution
Fight Medicine Research Institute selected and catalogued this study, prepared an original research summary, verified its bibliographic details, and maintains the associated citation record.
PDF files
- Open the record sheet (PDF): Effects of weight-cutting practices on sleep, recovery, and injury in combat sports
- Full text at PubMed Central: Effects of weight-cutting practices on sleep, recovery, and injury in combat sports
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Article details
- Relationship
- External research catalogued by the Fight Medicine Research Institute. The original authors, journal and DOI are unchanged.
- Published online
- 18 August 2025
- Repository date
- 18 August 2025 (Europe PMC first-publication date)
- Date used here
- 18 August 2025 (Crossref publisher deposit, online publication date)
- Rights
- CC BY 4.0. Open access under a Creative Commons Attribution licence (CC BY 4.0), as recorded by Europe PMC and the licence link in the source record. The summary on this page is Fight Medicine Research Institute’s own wording. No text or figure from the article is reproduced here. Licence terms.
- Source check
- , against PubMed Central full text, Crossref and Europe PMC. Checked under the direction of Casey C. Sears, Founder. An LLM was utilized as a research tool with direct human oversight.
- Appraisal
- The check covered bibliographic details, links, licence and notices. It is not a formal critical appraisal of the full paper.
- Clinical review
- None. This record is a research summary, not clinical education.
- Funding and conflicts
- The article states that the research received no external funding and that the authors declare no conflicts of interest.
- Catalog
- FH-058, added
Cite the original work
These files cite the work by its own authors, journal and DOI. Fight Medicine Research Institute appears only in a note, as curator of this catalog page.
Adrian Kużdżał, Oleg Bilianskyi, Zbigniew Wroński, Grzegorz Magoń, Gracjan Olaniszyn, Magdalena Hagner-Derengowska, et al.. Effects of Weight-Cutting Practices on Sleep, Recovery, and Injury in Combat Sports: A Scoping Review. Journal of Functional Morphology and Kinesiology. 2025;10(3):319. https://doi.org/10.3390/jfmk10030319
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