REF-779 · Hoffman & Krishnan, 2014 · PLoS ONE, Vol. · Paper · PubMed

Health and Exercise-Related Medical Issues among 1,212 Ultramarathon Runners: Baseline Findings from the Ultrarunners Longitudinal TRAcking (ULTRA) Study

B+moderate evidenceMeasured on recreational to highly trained athletesWritten before October 2026, being re-checked

Enrolment data from 1,212 active ultramarathon runners in the ULTRA Study were analysed for chronic disease, health-care use and risk factors for exercise-related injury. The most common chronic conditions were allergies/hay fever (25.1%) and exercise-induced asthma (13.0%); serious conditions were uncommon but present.

In the year before enrolment, 64.6% reported an exercise-related injury that cost training days (median 14 days), the knee was the most common site, and 5.5% had a stress fracture, most often in the foot. Injured runners were younger and less experienced, and stress fractures were more common in women.

Participants

n=1,212 active ultramarathon runners enrolled in the ULTRA Study; data retrospective and self-reported at enrolment. Age, sex split and race distances are not given in the abstract.

Protocol

Retrospective, self-reported enrolment questionnaire from an ongoing longitudinal observational study.
Outcomes: prevalence of chronic diseases, health-care use, days missed from work or school, exercise-related injuries in the preceding year and their risk factors.

Key Results

Chronic conditions (prevalence):

ConditionPrevalence
Allergies/hay fever25.1%
Exercise-induced asthma13.0%
Cancers4.5%
Coronary artery disease0.7%
Seizure disorders0.7%
Diabetes0.7%
HIV infection0.2%

Injuries in the year before enrolment:

64.6% reported an exercise-related injury that cost training days (median 14 days lost).
Median days off work or school for illness, injury or exercise-related conditions: 0 for each.
The knee was the most common area of exercise-related injury.
Stress fractures: prior-year incidence 5.5%, most (44.5%) involving the foot.
Injured runners were younger (p<0.001) and less experienced (p<0.01) than uninjured runners.
Stress fractures were more common in women than men (p<0.01).

Practical Application

Among 1,212 active ultramarathon runners, 64.6% reported an injury that cost training days in the past year (median 14 days), the knee was the most common site, 5.5% had a stress fracture (44.5% of them in the foot), and the younger, less experienced runners and, for stress fractures, women were most at risk (self-reported, cross-sectional). Getting hurt at least once a year is the norm in ultrarunning, not bad luck; the runner new to the distance is the one to protect.
A runner new to ultras should build distance and vertical gain more cautiously than an experienced one; inference, not tested here: inexperience here likely stands for a younger training history and less tolerance built up, but the paper reports only the association.
Foot pain that localises to a bone in a woman ultrarunner deserves particular suspicion of stress injury, given the higher stress-fracture rate in women and the foot as the most common site.
Exercise-induced asthma (13.0%) and allergies (25.1%) are common in this group; the authors say they are more prevalent than in the general population. Not from this paper; the base's own practice: breathing symptoms that come with exercise are a reason for a medical assessment, not for pushing through.
The authors compare the annual injury incidence with shorter-distance runners as similar, but with a higher proportion of foot stress fractures; the abstract gives no numbers for the comparison group.

Limitations

Retrospective and self-reported: injuries, diagnoses and stress fractures were not clinically confirmed.
Cross-sectional baseline data: associations (younger, less experienced, women) are not causes.
Enrolment was voluntary, so healthier or more engaged runners may be over-represented.
The comparisons with the general population and with shorter-distance runners are the authors' statements; the abstract gives no comparison numbers.
Written from the abstract and record metadata only (full text not read); injury definitions, age and sex split are not given here.
How this entry was checked and changed
Why this level

large observational sample (n=1212), self-reported, retrospective