Background: Measuring physiological parameters that are affected by military training and operational stress lead to identify optimal methods for enhancing the quality of military courses. The aim of this study was to investigate the effect of eight weeks of ranger training on pituitary-thyroid axis hormones among the students of Military University of Imam Ali.

Materials and Methods: In a quasi – experimental pretest-posttest design, 24 cadets were randomly selected and then divided into two experimental and control groups (n=12 in each group). First, before the start of course, participants attended the laboratory and their blood samples were collected to assess the level of thyroid hormones (T₃, T₄), and thyroid stimulating hormone (TSH). Then, the experimental group performed eight weeks of ranger training program while the control group did no exercise at all. To collect data on the post-test, we re-collected blood samples from subjects. Independent t-test for inferential analysis was performed using SPSS18 software.

Results: The findings showed that the ranger training program had a significant effect on serum T₃ (p=0.012). However, this training had no significant effect on serum T₄ (p=0.552) and TSH (p=0.574).

Conclusion: In general, these findings are useful in the implementation of favorite training regimens in order to sufficient recovery and prevention of overtraining.