Effect of Professional Fighters' Weight Class on Regional Brain Volume, Cognition, and Other Neuropsychiatric Outcomes

To read the full-text of this research, you can request a copy directly from the authors.


Objective To evaluate the relationship between professional fighter weight class and neuropsychiatric outcomes. Background Traumatic brain injury (TBI) is a common source of functional impairment among athletes, military personnel, and the general population. Professional fighters in both boxing and mixed martial arts (MMA) are at particular risk for repetitive TBI and may provide valuable insight into both the pathophysiology of TBI and its consequences. Currently, effects of fighter weight class on brain volumetrics (regional and total) and functional outcomes are unknown. Design/Methods n = 53 boxers and n = 103 MMA fighters participating in the Professional Fighters Brain Health Study (PRBHS) underwent volumetric magnetic resonance imaging (MRI) and neuropsychological testing. Fighters were divided into lightweight (=139.9 lb), middleweight (140.0–178.5 lb), and heavyweight (>178.5 lb). Results Compared with lightweight fighters, heavyweights displayed greater yearly reductions in regional brain volume (boxers: bilateral thalami; MMA: left thalamus, right putamen) and functional performance (boxers: processing speed, simple and choice reaction; MMA: Trails A and B tests). Lightweights suffered greater reductions in regional brain volume on a per-fight basis (boxers: left thalamus; MMA: right putamen). Heavyweight fighters bore greater yearly burden of regional brain volume and functional decrements, possibly related to differing fight dynamics and force of strikes in this division. Lightweights demonstrated greater volumetric decrements on a per-fight basis. Conclusions Although more research is needed, greater per-fight decrements in lightweights may be related to practices of weight-cutting, which may increase vulnerability to neurodegeneration post-TBI. Observed decrements associated with weight class may result in progressive impairments in fighter performance, suggesting interventions mitigating the burden of TBI in professional fighters may both improve brain health and increase professional longevity.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... After selection based on the pertinence and relevance to the topic of the review, 11,191 records were excluded, leaving 47 articles meeting the selection criteria. The full texts of the selected articles were assessed for inclusion, and 30 further articles were excluded as 3 were case reports [17,19,45], 1 review [46], 1 reported participation in sports as a leisure activity [47] 2 reported data only on an overall measure of physical activity [48,49] 2 included only athletes who had ≥ 1 head/brain injury [50,51] 8 did not report any measure of risk of NDs and/or NCDs [20,[52][53][54][55][56][57][58] and 13 were already included in the 2016 review [59][60][61][62][63][64][65][66][67][68][69][70][71]. ...
Full-text available
Objective The aim of this systematic review (SR) was to gather all available epidemiological evidence on former participation in any type of sport, at a professional and varsity level, as a potential risk factor for neurodegenerative diseases (NDs) and neurocognitive disorders (NCDs). Design Systematic searches were performed on PubMed, the Cochrane databases, and the ISI Web of Knowledge databases. Included studies were assessed using the NOS checklist. Eligibility criteria for selecting studies All epidemiological studies reporting data on the possible association between a clinical diagnosis of amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND), dementia or mild cognitive impairment (MCI), Parkinson’s disease (PD), chronic traumatic encephalopathy (CTE) at any stage and with any clinical pattern and the former participation in any types of sport at a varsity and professional level were included. Results Data from the 17 included studies showed a higher frequency of NDs and NCDs in former soccer and American football players. Updating the previous SR confirmed a higher frequency of ALS/MND in former soccer players. Data reported a significantly higher risk of dementia/AD in former soccer players, and of MCI in former American football players. Results also showed a significantly higher risk of PD in former soccer and American football players, and a significantly higher risk of CTE in former boxers and American football players. Summary/conclusions This SR confirmed a higher risk of NDs and NCDs in former professional/varsity athletes. However, the pathological mechanisms underlying this association remain unclear, and further high-quality studies should be performed to clarify whether the association could be sport specific.
ResearchGate has not been able to resolve any references for this publication.