Sleep and life after competition
What published studies report about fighters after they stop competing: sleepiness, mood, cognition and brain measurements.
Research information, not medical advice. This page does not diagnose, screen or clear anyone to compete.
The library holds one study that measures sleep, and it measures daytime sleepiness by questionnaire in retired male boxers. The other sources on this page compare retired or former fighters with active fighters or with controls.
One source covers a wider group than fighters: a cohort of retired athletes from several contact sports, with former amateur boxers as one subgroup.
What the sources report
Daytime sleepiness in retired male boxers
Esagoff et al., 2024. International Review of Psychiatry.
- Article type
- Observational cohort analysis
- Studied
- 86 retired male professional boxers.
- Status
- Published in a peer-reviewed journal
- 86 retired male professional boxers from the Professional Fighters Brain Health Study were included. Mean age was about 51 and the mean Epworth Sleepiness Scale score was 7.5.
- Higher sleepiness scores were associated with higher impulsiveness scores and higher depression scores in adjusted models.
- The relationship between number of professional bouts and impulsiveness and depression scores was mediated by sleepiness score.
Cognition and brain structure after fighters stop fighting
Zhuang et al., 2022. Neurology.
- Article type
- Longitudinal matched cohort analysis
- Studied
- 45 fighters who stopped fighting and sparring; 45 matched active fighters.
- Status
- Published in a peer-reviewed journal
- 45 male fighters who had no sanctioned fights and no sparring for two years were compared with 45 matched male fighters who stayed active.
- The two groups followed different paths in verbal memory, psychomotor speed, processing speed and neurofilament light levels. Fighters who stopped showed improved cognitive scores and falling neurofilament light. Active fighters showed declining cognitive scores.
- Cortical thickness measures stabilised at group level in the fighters who stopped and declined slightly in those who stayed active.
Regional brain volumes over time with repetitive head impacts
Bernick et al., 2020. Neurology.
- Article type
- Longitudinal cohort analysis
- Studied
- 204 participants with repeated assessments, including fighters and controls.
- Status
- Published in a peer-reviewed journal
This study reports separate results for retired boxers.
- 204 participants with at least two assessments were analysed.
- Compared with controls, active boxers showed a faster yearly decline in the volume of the left thalamus and parts of the corpus callosum. Retired boxers showed the largest declines in the amygdala and right hippocampus.
Win-loss record, neuropsychiatric symptoms and brain health
Bryant et al., 2024. The Journal of Neuropsychiatry and Clinical Neurosciences.
- Article type
- Observational professional-fighter cohort analysis
- Studied
- 212 professional fighters.
- Status
- Published in a peer-reviewed journal
This study reports separate results for retired fighters.
- Data from 212 professional fighters in the Professional Fighters Brain Health Study were analysed.
- Among retired fighters, a better win-loss record was associated with more impulsiveness, slower processing speed and smaller volumes in several brain regions.
Mental health symptoms in current and former elite kickboxers
Bilgoe et al., 2025. Discover Mental Health.
- Article type
- Cross-sectional survey
- Studied
- 45 current and 29 former elite kickboxers.
- Status
- Published in a peer-reviewed journal
This study reports separate results for 29 former elite kickboxers.
- 45 current and 29 former elite kickboxers answered screening questionnaires from the International Olympic Committee Sport Mental Health Assessment Tool 1.
- Among current kickboxers, the most common positive screens were disordered eating (63%) and psychological distress (57%). Among former kickboxers, they were alcohol misuse (43%) and psychological distress (36%).
Suicide and depression in former contact sports participants
Batty et al., 2023. eClinicalMedicine.
- Article type
- Population cohort study plus systematic review and meta-analysis
- Studied
- 2,004 retired Finnish male international amateur athletes and 1,385 controls; boxing subgroup included.
- Status
- Published in a peer-reviewed journal
Scope: Broader contact-sports population. The cohort includes former amateur boxers as one subgroup, alongside wrestlers and soccer players. The pooled analysis concerns soccer and American football.
- 2,004 retired Finnish male athletes who had competed internationally as amateurs and 1,385 general-population controls were linked to hospital and death registries.
- Former boxers did not have statistically higher rates of major depressive disorder or suicide than controls (depression hazard ratio 1.43, 95% CI 0.73 to 2.78; suicide hazard ratio 1.75, 95% CI 0.64 to 4.38).
- Seven other cohort studies were pooled with the Finnish data. The pooled results reported in the abstract concern soccer and American football.
Limits of this evidence
- Daytime sleepiness was measured by questionnaire in one study of 86 retired male boxers.
- Participants were volunteers or members of a registry cohort. The studies do not describe all former fighters.
- Three of the studies on this page included only men.
Fight Medicine Research Institute checked each source’s details against PubMed, Crossref, Europe PMC or the publisher. It has not carried out a formal critical appraisal of each paper.