Impact of compulsory military service on public health: significant benefits for obese and unfit young adult men

Obesity and poor physical fitness are essential concerns for public health and disease prevention. Alarmingly, the prevalence of both risk factors is increasing in younger populations. We investigated what is the impact of compulsory military service on waist circumference and cardiorespiratory fitness in large sample of Finnish young men. Our study was based on a database from the Finnish Defence Forces, which includes information on 249,279 healthy male conscripts (age 19.1 ± 0.4 years.). We measured the waist circumference, and cardiorespiratory fitness (12-min running test) of conscripts in the beginning and at the end of the service and evaluated how these values differed in individuals with different baseline data. The mean changes in waist circumference and cardiorespiratory fitness were −2.1 cm [95% confidence interval (CI): −2.2 to −1.9] and +62 m (95% CI: 57–68). Conscripts with the largest waist circumference at baseline decreased their value the most and conscripts with the poorest cardiorespiratory fitness at baseline increased their fitness the most. Compulsory conscription benefits public health by reducing waist circumference and improving cardiorespiratory fitness of initially obese and unfit young men. Changes, if maintained, are likely to translate into lower morbidity and mortality of chronic illnesses. Interventions containing similar features as military services including increased physical activity, regular sleep and healthy eating habits could be considered in decision making to counteract the growing problem of obesity and poor physical fitness. Obesity, and poor cardiorespiratory fitness are among the leading global public health concerns. Both are risk factors for several noncommunicable diseases. The potential of compulsory military service to decrease waist circumference, a measure for harmful ectopic adipose tissue, and to increase cardiorespiratory fitness in population-level is unknown. Compulsory military service decreased waist circumference and improved cardiorespiratory fitness. The service was especially beneficial for young men with baseline waist obesity and poor cardiorespiratory fitness. Compulsory conscription can be considered as an effective population-level intervention to improve body composition and physical fitness of young men from public health perspective.