Abstract
We aimed to identify potential physiological and performance differences of
trained cross-country skiers (V˙o2max=60±4
ml ∙ kg–1 ∙ min–1)
following two, 3-week long altitude modalities: 1) training at moderate
altitudes (600–1700 m) and living at 1500 m (LMTM;N=8); and 2)
training at moderate altitudes (600–1700 m) and living at 1500 m with
additional nocturnal normobaric hypoxic exposures
(FiO2 =0.17;LHTM; N=8). All participants
conducted the same training throughout the altitude training phase and underwent
maximal roller ski trials and submaximal cyclo-ergometery before, during and one
week after the training camps. No exercise performance or hematological
differences were observed between the two modalities. The average roller ski
velocities were increased one week after the training camps following both LMTM
(p=0.03) and LHTM (p=0.04) with no difference between the two
(p=0.68). During the submaximal test, LMTM increased the Tissue
Oxygenation Index (11.5±6.5 to 1.0±8.5%;
p=0.04), decreased the total hemoglobin concentration (15.1±6.5
to 1.7±12.9 a.u.;p=0.02), and increased blood pH
(7.36±0.03 to 7.39±0.03;p=0.03). On the other hand, LHTM
augmented minute ventilation (76±14 to 88±10
l·min−1;p=0.04) and systemic blood oxygen
saturation by 2±1%; (p=0.02) with no such differences
observed following the LMTM. Collectively, despite minor physiological
differences observed between the two tested altitude training modalities both
induced comparable exercise performance modulation.
Key words
moderate altitude training - muscle oxygenation - blood pH - ventilation - normobaric
hypoxia
