Stress Fracture and Attrition in Basic Underwater Demolition SEAL Trainees

The Basic Underwater Demolition SEAL (BUD/S) training program is a six-month rigorous program that prepares trainees for specialized instruction before being assigned to a SEAL team. Two major but separate issues affect this program: stress fractures and attrition. Stress fracture rates are around 5-9% and may lead to attrition or training delays. Ultimately, only about 25% of trainees complete the program. The purpose of this study was to examine both stress fractures and attrition outcomes among BUD/S trainees by evaluating a combination of administrative records and self-reported health behavior data. Methods: The study was conducted at the Naval Special Warfare Center (NAVSPECWARCEN) BUD/S training program in Coronado, California, between April 2002 and November 2003 (classes 241 to 249). The trainees (n = 1046) were followed from the start of training to graduation (at least six months) or attrition. A 33-item health habits questionnaire was administered to the trainees upon entry. Other data sources included BUD/S training records, the NAVSPECWARCEN Command Information Management System, the Naval Medical Center San Diego medical and radiological database, and the Career History Archival Medical and Personnel System. Results: During the training period, 72 men (6.9%) incurred at least one stress fracture or stress reaction. Men reporting shin pain “most or all of the time” (potentially indicating recent or existing injury) on the baseline questionnaire had three times the risk of developing a stress fracture during training, even after controlling for low body mass index (BMI). Running pace, frequency, and age were not associated with stress fractures. For attrition outcomes, only 26% of the trainees graduated and half of those men took more than 263 days to finish the program. Successful graduates were more likely to have high BMI, high education, officer rank, and the modifiable factors were self-reported measures of fitness, intensity of workouts, ability to do more than 10 pull-ups, and never smoking tobacco. Not all factors were equally associated with on-time graduation, delayed graduation, and overall graduation. Many of the self-reported behaviors were associated with overall graduation, but only the ability to do more than 10 pull-ups was associated with on-time graduation. Stress fracture occurrence was associated with delayed graduation, but not with overall graduation. Discussion: Very few of the expected risk factors were found for stress factures in this population. The attrition analyses found differences in risk factors between those who graduated on time, late, and not at all. Conclusions: Future studies should analyze training days of exposure to further explore the timing and risk factors for stress fractures. However, a better understanding of stress fractures, though valuable in itself, will not necessarily clarify attrition. The large number of voluntary drops contributed substantially to a low graduation rate and should be the focus of future studies. Disclosure Statement: The views contained herein are those of the authors and do not necessarily reflect the official Department of Defense position. The United States Special Operations Command and the Journal of Special Operations Medicine do not hold themselves responsible for statements or products discussed in the article. Unless so stated, material in the JSOM does not reflect the endorsement, official attitude, or position of the USSOCOM-SG or of the Editorial Board.