To study the respiratory and physical health of young men, 224 asthmatic and 668 non-asthmatic military conscripts were recruited from the intake groups of July 2004 and January 2005 in Kajaani, Finland. Factors affecting respiratory health were elicited by a questionnaire at the beginning of the service, and results of high sensitive C-reactive protein (hsCRP) determination, peak expiratory flow (PEF), and 12-minute running test were collected at the beginning and the end of the service. Respiratory infections were diagnosed by a study physician. Upon entering military service, asthmatics had frequent exercise- and cold-related asthma symptoms (69.6% and 76.3%), and 48% of them had no medication for asthma. At the beginning, 25.8% of asthmatics and 19.1% of non-asthmatics had a poor result of less than 2,200 m (p = 0.05) in the 12-minute running test, and after 180 to 362 days of service, the corresponding percentages were 11.7% and 9.7% (p = 0.434). The levels of hsCRP, a marker of low-grade systemic inflammation, decreased significantly among both asthmatics, 1.5 (p = 0.001), and non-asthmatics, 1.6 mg/L (p < 0.001). Asthmatic men had 0.2 and non-asthmatics 0.1 respiratory infections per month (p < 0.001). In summary, asthmatic conscripts can enhance their physical fitness by training similarly to non-asthmatic ones. Their levels of hsCRP also decrease.