A cross sectional study was carried out to evaluate the level of physical fitness of new recruits of the central security forces and to study the effect of training and other various ecological factors on the level of their physical fitness. Seven hundred and twenty individuals were selected from the training camp of central security forces at Quesna district. Menoufia Governorate to be the subjects of this study. The results showed that the training program had a significant positive effect on the physical fitness response and pulmonary function measurements of recruits. Smoking habits residence. Hemoglobin concentration and bilharzial infection were important factors affecting response to training.