Published in a peer-reviewed journal
Effect of Weight Class on Regional Brain Volume, Cognition, and Other Neuropsychiatric Outcomes among Professional Fighters
Michael J. C. Bray, Jerry Tsai, Barry R. Bryant, Bharat R. Narapareddy, Lisa N. Richey, Akshay Krieg, William Tobolowsky, Sahar Jahed, Guogen Shan, Charles B. Bernick, Matthew E. Peters. 2021. Neurotrauma Reports.
Summary
The study examined weight class, brain volumes, cognition, depressive symptoms, and impulsivity in professional fighters, reporting different trajectories across weight classes and sports.
What the work reports
- Fighters had brain MRI scans and cognitive testing, and completed questionnaires on depressive symptoms, impulsivity and daytime sleepiness. The authors grouped them as lightweight (139.9 lb and under), middleweight (140.0 to 178.5 lb) or heavyweight (over 178.5 lb).
- Compared with lightweights, heavyweights showed larger yearly reductions in the volume of some deep brain structures and in some measures of thinking speed. The structures and tests differed between boxers and MMA fighters.
- Lightweights showed larger reductions in some of those structures per professional fight. The authors raise weight cutting as one possible explanation and say it needs more research.
Limits to keep in mind
- The authors combined the sport’s many weight divisions into three groups.
- The authors report that no sample-size calculation was done in advance, so a result showing no difference may reflect too few fighters.
- The study shows patterns across groups of fighters. It does not predict what will happen to any one fighter.
Publication status
Published in a peer-reviewed journal. Original research article in Neurotrauma Reports.
No correction or retraction notice was found in Crossref, PubMed or Scite when this record was checked.
Rights
CC BY 4.0. Open access under the Creative Commons Attribution 4.0 License. The summary on this page is FMRI’s own wording. No text or figure from the article is reproduced here. Licence terms.
FMRI’s role
None. This is external research by the authors and institutions named. FMRI lists it and summarizes it in its own words.
See the source record for the authors' funding and disclosures.