Fighter health

Read this first

This page reports what specific studies found. It is not medical advice, and it cannot tell you what is happening in your own body. If something is wrong, see a doctor. If you were hurt in a bout or in sparring and you feel worse, get medical care now.

Every statement below links to a research record. The record tells you who did the work, who was studied, how strong the study is and where it falls short.

What the library reports

After the bout: checking for a head injury

One record in the library reviews the evidence on concussion screening at ringside and describes a structured examination for use after a bout. Its source states two things every fighter should know: a normal screen cannot rule out a concussion, and the examination never clears a fighter or permits a same-day return.

The work is a preprint. It has not been peer reviewed, and the examination it describes has not been validated in any sport.

Source: Standardized post-bout ringside concussion screening in combat sports (Sears, 2026)

Who can stop your fight

One record examines how United States commission rules assign the authority to stop a bout. It is a critical review of an earlier article. The review reports that the earlier article’s main finding did not hold up when checked against the rules themselves, and it questions whether giving physicians independent stoppage authority makes fighters safer.

Source: Ringside physician stoppage authority in United States combat sports commissions (Sears, 2026)

Your brain over a career

A study of 53 professional boxers and 103 professional MMA fighters used brain scans and thinking tests. Compared with lightweights, heavyweights showed larger yearly reductions in the volume of some deep brain structures and in some measures of thinking speed. 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.

The study shows patterns across groups of fighters. It does not predict what will happen to any one fighter.

Source: Weight class, brain volume and cognition in professional fighters (Bray et al., 2021)

CTE

Chronic traumatic encephalopathy (CTE) is a degenerative brain condition. A 2023 commentary in a forensic pathology journal states that its only known cause is repeated blunt head trauma. In both CTE records in the library, the condition was identified by examining brain tissue after death.

In 2018, researchers re-examined preserved tissue from 14 boxers first studied in 1973. Seven of the 14 met the criteria for CTE that the researchers applied. Fourteen cases cannot tell anyone how common CTE is among boxers.

Source: CTE: features and forensic considerations (Byard et al., 2023)

Source: The aftermath of boxing revisited (Goldfinger et al., 2018)

Mood and confidence

A study of 231 boxers in China used questionnaires. Boxers who scored higher on confidence in their own ability and on self-control reported fewer depressive symptoms. Everything was measured at one point in time, so the study shows a link and cannot show what causes what. The authors note that the questionnaires had not been validated in boxers.

Source: Self-efficacy and depression in boxers (Chen et al., 2020)

Where the library is empty

The library does not yet hold a verified record on emergency response at events, on post-traumatic stress disorder in fighters, or on suicide risk in fighters. Those are three of FMRI’s research priorities for that reason.

How to read a study label

Every record in the library carries labels. This is what they mean.

Preprint

A manuscript made public before other experts have reviewed it. Treat its findings as provisional.

Peer reviewed

Other experts examined the work before publication. Peer review lowers the chance of error. It does not make a finding certain.

Systematic review

A study of studies. The authors search for all the research on a question using a stated method and report what it shows together.

Cohort study

A group of people is followed over time, and changes are measured.

Cross-sectional study

Everything is measured once. It can show that two things go together. It cannot show that one causes the other.

Commentary

Experts explain or argue a point. A commentary reports no new data from participants.

Validated

A test has been checked against a trusted standard in the people it will be used on. A test that has not been validated may still be useful, but nobody has shown how accurate it is.

If you are asked to join a study

These are the rules FMRI proposes for its own research. They are also fair questions to put to anyone who asks you to take part in a study.

• You can say no. Declining or leaving a study must not affect your licence, your bouts, your purse, your ranking or your medical care.
• The person asking should have no hold over your career. A commissioner, promoter, manager, coach or clearing physician should not be the one recruiting you.
• Not right after a fight. If you have just been knocked out, stopped or hurt, you should not be asked to sign anything.
• Care comes first. A study must never delay your examination, treatment or transport.
• Ask who sees your results. You should be told before you agree whether anything could go to a commission, a promoter or anyone else, and why.
• Ask who reviewed the study. A study with people should hold a written determination from an independent ethics review board before it starts.
• Ask for the results. A study should offer to tell you what it found, in words you can use.

The full proposed rules are in FMRI’s participant protection policy. FMRI is not recruiting for any study.

Tell FMRI what to study

FMRI’s proposed charter gives fighters a formal voice through a fighter advisory council. Before the council is seated, FMRI still wants to hear which questions matter to you.

FMRI has not yet published a contact address. It will not list one until the address reaches a monitored inbox. When that is in place, the address will appear here and on the Contact page.

Do not send medical details, test results or anything about a personal crisis.