Cigarette smoking and exercise-related injuries among young men and women.

BACKGROUND: We evaluate whether a recent history of cigarette smoking is a risk factor for exercise-related injuries sustained during Army basic training, controlling for factors such as demographic, physical fitness, and health variables. METHODS: We conducted an observational cohort study in 1087 male and 915 female Army recruits undergoing 8-week basic military training. Data were collected from questionnaires, anthropometric measurements, physical fitness tests, company training logs, and medical records of all clinic visits. RESULTS: During the 8-week training period, 33% of men and 50% of women had at least one clinic visit for injury, including 14% of men and 25% of women who lost more than 5 days of training due to injury. Recruits who reported smoking at least one cigarette in the month prior to beginning basic training (which was conducted in a smoke-free environment) had significantly higher injury rates during training than those who did not report smoking (40% versus 29% for men, and 56% versus 46% for women). The relationship with smoking history was present most strongly for overuse injuries (32% versus 24% in men and 51% versus 40% in women). Multiple logistic regression analyses controlling for all other factors consistently showed adjusted odds ratios of about 1.5 for injury rate in those with a history of smoking compared to those without. CONCLUSIONS: The association of history of cigarette smoking with injury occurrence was consistent throughout the analyses, with very little confounding by other factors. The detrimental effects of smoking on injuries appears to persist at least several weeks after cessation of smoking.

Effect of rest from running on overuse injuries in army basic training.

BACKGROUND: It has been hypothesized that a period of rest from running in the early weeks of basic military training will prevent stress fractures among recruits. DESIGN: Modification of running schedules in companies of Army recruits undergoing basic military training was assigned. SETTING/PARTICIPANTS: Six male training companies were enrolled and followed during their 8 weeks of basic military training at Fort Bliss, Texas, in summer/fall 1989. INTERVENTION: Intervention companies were asked to rest from running during the second, third, or fourth week of basic military training. MAIN OUTCOME MEASURES: Data were collected from questionnaires, anthropometric measurements, Army physical fitness tests, company training logs, and medical record abstraction of all clinic visits. RESULTS: Among the 1357 enrolled male recruits, there were 236 (17%) with overuse injury and 144 (11%) with traumatic injury, resulting in 535 clinic visits and 1927 training days lost. Stress fracture/reaction rates varied from 3 to 8 per 100 recruits among the intervention companies and 2 to 7 per 100 recruits among the non-intervention companies. Total injury rates were 18 to 35 per 100 recruits in the intervention companies and 18 to 29 per 100 recruits in the non-intervention companies. CONCLUSIONS: The study provided no evidence for a protective effect on overuse injuries of resting from running for 1 week early in basic military training. There was varied physical training among the companies, however, with variation of injury rates that likely related to factors other than the intervention.