1. Rodríguez, F.A., Iglesias X., Barrero A., Ábalos X.,
Moreno D., Abellán R., Segura J. Intermittent
Hypobaric Hypoxia Exposure increases ventilatory
treshold but not running performance in triathletes.
1st WORLD CONFERENCE OF SCIENCE IN
TRIATHLON. Alacant, 2011.
Sport Sciences Research Group INEFC Barcelona
Grup de Recerca en Ciències de l'Esport INEFC Barcelona
Grup Consolidat (2009 SGR1054)
Institut Nacional d’Educació Física de Catalunya
Av. de l’Estadi, 12-22
08038 Barcelona (Spain)
+34 93 425 54 45 grce@gencat.cat @Recerca_INEFC

2. Presented at the I World Congress of Science in Triathlon. Alicante, Spain, March 24-26, 2011.
INTERMITTENT HYPOBARIC HYPOXIA EXPOSURE INCREASES VENTILATORY
THRESHOLD BUT NOT RUNNING PERFORMANCE IN TRIATHLETES
Rodríguez FA1, Iglesias X1, Barrero A1, X. Ábalos1, Moreno D1, Abellán R2, Segura J2
1
Institut Nacional d’Educació Física de Catalunya, INEFC Barcelona Sport Sciences Research Group. Universitat de
Barcelona
2
Institut Municipal d’Investigació Mèdica (IMIM), Departament of Pharmacology. Barcelona, Spain.
Presenting author:
Ferran A. Rodríguez
Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona
farodriguez@gencat.cat
Introduction: Short-term intermittent hypoxia exposure (IHE) combined with sea level training has shown to improve
cycling performance in world-class track cyclists (1), and middle-distance swimming performance (2-3) or VO2max and
ventilatory threshold in competitive swimmers (2-3). This study investigated the effect of IHE on aerobic capacity and
running performance in triathletes.
Methods: After initial testing (Pre), 14 male triathletes of national level were matched and randomly assigned to either
hypoxia (HYPO) or normoxia (NORM) groups. The HYPO group was exposed to IHE at rest for 3 h/day, 5 days/week,
for 4 weeks in a hypobaric chamber (4,000 up to 5,500 m). At Pre, immediately after (Post), and two weeks later (Post
2wk), subjects performed a graded running test in a 400-m track and velocity at VO2max (vVO2max) was determined.
At Pre and one week afterwards (Post 1wk), subjects performed a graded, maximal test on a treadmill. Breath-by-breath
gas exchange parameters were monitored (CPXII, Medical Graphics, USA), and ventilatory thresholds (AT1vent,
AT2vent) were calculated.
Results: 12 subjects completed the study, and their results are summarized in the table.
HYPO (n = 5) NORM (n = 7)
Pre Post Post 1wk Post 2wk Pre Post Post 1wk Post 2wk
vVO2max, km·h-1 16.2 ± 1.1 16.2 ± 1.1  16.4 ± 0.9 16.5 ± 1.0 16.3 ± 1.0  16.3 ± 0.8
VO2max, mL·kg-1·min-1 58.8 ± 4.6  61.0 ± 4.4  60.3 ± 9.5  60.9 ± 5.9 
VCO2max, mL·min-1 5345 ± 390  4882 ± 359*  5465 ± 804  5063 ± 546 
AT1vent, %VO2max 79.8 ± 3.9  83.3 ± 3.1*  80.5 ± 5.6  78.5 ± 5.7* 
AT2vent, %VO2max 89.1 ± 2.3  92.4 ± 2.0**  94.5 ± 2.7  91.6 ± 2.9** 
* p<0.05, ** p<0.001 compared with Pre (MANOVA, Student post-hoc test); data are mean ± standard deviation
Discussion/Conclusion: AT1vent (+4.4%) and AT2vent (+3.8%) significantly increased, while CO2 production at
maximal effort decreased (8.6%) in the HYPO group. VO2max did not significantly change, although a trend was
observed in the HYPO group (+3.7%, p=0.2). These results could not confirm previous observations in which VO2max
during swimming significantly increased after IHE during two weeks (2). In contrast with the previously observed
increase in performance in an maximal 4-min cycling test (1), and 200-m swimming time trial (2), this longer protocol
did not improve graded running performance in the track. The increase of ventilatory thresholds is in line with previous
results with swimmers, but not with runners, exposed to an identical IHE protocol (3).
References:
1. Rodríguez FA, Cabanes T, Iglesias X, Huertas M, Casas H, Ventura JL. Intermittent hypobaric hypoxia enhances
cycling performance in world-class track cyclists. Proceedings, 7th Annual Congress of the European College of
Sport Science; Athens: ECSS, University of Athens; 2002.
2. Rodríguez FA, Murio J, Ventura JL. Effects of intermittent hypobaric hypoxia and altitude training on
physiological and performance parameters in swimmers. Medicine and Science in Sports and Exercise.
2003;35(5):S115.
3. Rodríguez FA, Truijens MJ, Townsend NE, Stray-Gundersen J, Gore CJ, Levine BD. Performance of runners and
swimmers after four weeks of intermittent hypobaric hypoxic exposure plus sea level training. J Appl Physiol.
2007;103(5):1523-35.