Recruits were asked before they started training about their smoking habits, and researchers kept track of the new soldiers' clinic visits during training.
Forty percent of men who had smoked reported an injury, compared with 29 percent of nonsmokers. Among women, 56 percent of the smoking group reported an injury, compared with 46 percent of nonsmokers.
One factor possibly accounting for smokers' higher injury risk is their lower levels of fitness at the start of training, according to the report. Other studies show that smokers have less endurance than do nonsmokers. Injury rates are higher among those less fit, because they fatigue more easily.