ABSTRACT
Objective To study the changes of ventilatory function of young soldiers coming from different regions during cold - tol-erance training. Methods The recruited young soldiers were divided into 2 groups:Group Ⅰ (50 coming from the northern region)and group Ⅱ (50 coming from the southern region) . According to the new training outline of cold -tolerance in winter,their ventilatory func-tions were tested before training and 60 days after training. Ventilatory functions were compared between smoking and non - smoking sub-jects. Results 25% forced expiratory flow (FEF25%) , 50% forced expiratory flow (FEF50%) and 75% forced expiratory flow (FEF75 %) were significant different between two groups before the course of training (P < 0.05). After 60 days, ventilatory functions of two groups were improved significantly as compared with that before training (P <0.01 ,P <0.05). There was no significant difference in ventilatory between two groups after 60 days of training (P > 0.05). There was significant difference in partial small airway function be-tween smoking and non - smoking subjects. Conclusion Cold air could decline the small airway function of soldiers coming from south-ern region before training. Cold -tolerance training has significant influence on soldiers' ventilatory function. Long- term and heavy smok-ing could decline the small airway function.