Training-related risk factors in the etiology of overuse injuries in endurance sports.
OBJECTIVE
The purpose of this study was to clarify training-related risk factors for overuse injuries.


METHODS
This was twelve-month retrospective study which was done by self-reported postal questionnaire. The study group consisted of 446 men and women top-level Finnish athletes representing three different endurance sports (cross-country skiing, swimming, long-distance running) between the ages of 15-35. Self-reported anthropometric and training-related variables (such as starting age of training, years of active training, hours trained yearly, competition hours and weekly resting days) and occurrence of overuse injuries.


RESULTS
Athletes with less than 2 rest days per week during the training season had 5.2-fold risk (95% confidence intervals [CI] 1.89-14.06, P=0.001) for an overuse injury, and athletes who trained more than 700 hours during a year had 2.1-fold risk (95% CI 1.21-3.61, P=0.008) for an overuse injury compared to the others. Athletes who reported a tendon injury were on average two years older than athletes without such an injury (P<0.001).


CONCLUSIONS
We found that low number of recovery days and a high amount of training are training-related risk factors for overuse injuries in top-level endurance athletes. The higher number of tendon overuse injuries in older than younger athletes may indicate that age-related degeneration plays an important role in the etiology of tendon injuries. These findings should be taken into account when planning exercise programs for endurance athletes.
ORTON Orthopaedic Hospital ORTON Foundation, Helsinki, Finland - leena.ristolainen@orton.fi.
L
L
Ristolainen
J A
JA
Kettunen
B
B
Waller
A
A
Heinonen
U M
UM
Kujala
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001265:Athletic Injuries / Q000209:etiology*; D012090:Cumulative Trauma Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D064797:Physical Conditioning, Human / Q000009:adverse effects* / Q000379:methods; D010807:Physical Endurance / Q000502:physiology; D012146:Rest / Q000502:physiology; D012189:Retrospective Studies; D012307:Risk Factors; D013708:Tendon Injuries / Q000209:etiology; D055815:Young Adult