All the subjects lived at sea level throughout the study.
As physical activity students, they were active subjects
but anyone among them was a weight trainer or sprint
runner. No one was a competitive athlete or was maintaining
a non-study related training throughout the protocol
with a potential alien impact on the post-study outcomes.
Three training sessions were performed weekly for a month
(4 weeks). Each session lasted for about two hours, was
conducted at room temperature (ranging from 20—24 ◦C)
and was exactly equal in workload and volume for both
groups. The NOR group trained at near sea level (75 m a.s.l),
whereas the HYP group trained inside a computer-controlled
hypobaric chamber (CHEx-1; Moelco, Spain) at a barometric
pressure of 747 hPa, equivalent to 2500 m of altitude.
The HYP group was exposed to hypobaric hypoxia for a
total time of about 26 hours. The time of ‘‘ascent’’ to altitude
inside the hypobaric chamber (10 min) was used for
warming-up, and the ‘‘descent’’ (15 min) for the recovery
procedure, and an identical procedure was also established
for the NOR group. All subjects were instructed on the
level of effort required during training. None described
intolerance to training under normoxic nor hypoxic conditions.