Forty male soldiers (20.1 ± 0.9 years) participated in the
trial after being informed of the purpose and details of the
trial, any known risks and discomforts, and their right to terminate participation at will. After briefing, the soldiers gave
their written informed consents to participate. The experimental protocol was approved by the Ethical Committee of
the Military Medical Academy in Belgrade. Medical supervision of the subjects was conducted according to international
standards 9. Standard anthropometric measurements were
conducted, baseline levels of maximal aerobic power
(VO2max) was indirectly determined on treadmill.
The investigation was conducted during wintertime
(late November and December) in Military Medical Academy, Belgrade. The soldiers were randomly divided into four
equal groups. The first group were unacclimatized control