Background: We evaluate whether a recent history of cigarette smoking is a
risk factor for exercise-related injuries sustained during Army basic train
ing, controlling for meters such as demographic, physical fitness, and heal
th variables.
Methods: We conducted an observational cohort study in 1087 male and 915 fe
male Army recruits undergoing 8-week basic military training, Data were col
lected from questionnaires, anthropometric measurements, physical fitness t
ests, 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 wome
n who lost more than 5 days of training due to injury. Recruits who reporte
d smoking at least one cigarette in the month prior to beginning basic trai
ning (which was conducted in a smoke-free environment) had significantly hi
gher 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 analy
ses controlling for all other factors consistently showed adjusted odds rat
ios of about 1.5 for injury rate in those with a history of smoking compare
d to those without.
Conclusions: The association of history of cigarette smoking with injury oc
currence was consistent throughout the analyses, with very little confoundi
ng by other factors. The detrimental effects of smoking on injuries appears
to persist at least several weeks after cessation of smoking.