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 [email protected]@Recerca_INEFC
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Intermittent Hypobaric Hypoxia exposure increases ventilatory treshold but not running performance in triathletes
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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
Intermittent Hypobaric Hypoxia Exposure Increases Ventilatory Threshold But Not
Running Performance In Triathletes
Rodríguez FA, Iglesias X, Barrero A, Ábalos
X, Moreno D, Abellán R, Segura J
IMASInstitut Municipald’Investigació Mèdica. IMIMPharmacology Research Unit
Rodríguez 2005 ECSS Congress
Altitude TrainingNatural hypobaric hypoxia
at altitude (mountains)
LH-THHigh-High
LH-TLHigh-Low
Contemporary Applications of Hypoxia
to Athletic Training
Intermittent HypoxiaArtificial hypoxia
(Hypobaric / Normobaric)
IHEIntermittent
Hypoxia Exposure
IHTIntermittent
Hypoxic Training
LL-THLow-High
LH-THO2+ Suppl. O2
IHITIH Interval Training
Please see keynote conference by Dr. Randy Wilber
"Training in Altitude“
(12 h)
Rodríguez 2005 ECSS Congress
Altitude TrainingNatural hypobaric hypoxia
at altitude (mountains)
LH-THHigh-High
LH-TLHigh-Low
Contemporary Applications of Hypoxia
to Athletic Training
Intermittent HypoxiaArtificial hypoxia
(Hypobaric / Normobaric)
IHEIntermittent
Hypoxia Exposure
IHTIntermittent
Hypoxic Training
LL-THLow-High
LH-THO2+ Suppl. O2
IHITIH Interval Training
The short-term IHE model
• Short-term IHE in climbers and endurance athletes 9-21 d, 1.5-5 h/d, 4000-5500 m1-8
• Erythropoietic response EPO, PCV, retics1-7 but not Hbmass increase8
• Increased VO2 max in climbers (+6.2%)1 and swimmers +5.4%6, +3.3%8, but not in runners8
• Improved performance in middle-distance swimmers +0.9% in 200-m time6, world-class track cyclists +2.9% in 4’ trial)7
but not in swimmers and runners8
1 Casas et al. 1998 J Sports Sci2 Casas et al. 2000 Aviat Space Environ Med3 Rodríguez et al. 1998 J Sports Sci4 Rodríguez et al. 1999 Med Sci Sports Exerc
5 Rodríguez et al. 2000 Eur J Appl Physiol6 Rodríguez et al. 2002 IX WSBMS7 Rodríguez et al. 2002 7th ECSS Congress, Athens8 Rodríguez et al. 2007 J Appl Physiol
IHE at hypobaric chamber Randomized, double blind, placebo controlled study
23 trained athletes (10 runners, 13 swimmers)3-km and 100/400-m time trial (performance markers)submax and maximal VO2 (treadmill or flume)3 h/d, 5 d/wk, 4 wks
Gore et al. 2006 J Appl Physiol Rodríguez et al. 2007 J App Physiol Truijens et al. 2008 J Appl Physiol
Intermittent Hypoxia Study 2003
• To examine the effect on triathletes of 4 weeks of moderate-severe IHE in a hypobaric chamber (SA 4,000-5,500 m) on
aerobic capacity running performance
• Hypothesis: aerobic capacity and running performance would further improve in the IHE group as compared to sea level control group
Aims
Subjects
• 14 male triathletes
• Age 19-37 y, height 172-185 cm, body mass 66-84 kg
• Regular training 7-25 h/wk
• Competing at regional/national level
• Continued to train at sea level throughout the study
Experimental Design
• Randomised controlled trial
• Subjects assigned to HYPO or NORM group (n=7 each)
• Very similar training schedule at SL (ave. 20 h/wk)
• Same supplementation (Fe, folate, vitamins A, C, & E, Mg)
HYPO Sea level training IHE at rest: 4 weeks, 5 d/wk, 3 h/d at 4,000-5,500 m
NORM SL training only
0
1000
2000
3000
4000
5000
6000
1 8 15 22 29 36 43 50
Time (days)
Sim
ulat
ed a
ltitu
de (m
)
t1t1´
Treadmill test
Pre Post 1 Post 2
t3
Field test (UMTT)
Blood tests
t2t2´
Chronogram
• Université de Montréal Track Test (UMTT)* to determine MAS (vVO2 max) in a synthetic 400-m track
v0 = 7 km·h-1
v = 1 km·h-1 / 2 min
Running Field Testing
* Léger & Boucher 1980 Can J Appl Sports Sci
• Maximal, incremental test on a running treadmillv0 = 6 km·h-1
v = 1 km·h-1 / 1 minslope 5%
• Expired gas continuously measured BxB CPXII, Medical Graphics, USA
• Highest 15 s averaged VO2 = VO2 max
• Ventilatory thresholds VT1 VT2 = RCP
Treadmill Running Test
• MANOVA (general linear model, SPSS)
• Main effects time: Pre, Post, Post 1 wk, Post 2 wk treatment: HYPO vs NORM
• Time x treatment interaction
• Post-hoc paired comparisons (Student)
Statistical Analysis
VO2 max
NORM
% Change of VO2max
-14
-10-6
-2
2
610
14
18
Pre Post 1
HYPO
% Change of VO2max
Pre Post 1
NORM HYPO
+3.7%p=0.2
VT1
NORM
% Change in VT1 (% VO2max)
-12
-8
-4
0
4
8
12
Pre Post 1
HYPO
% Change in VT1 (% VO2max)
Pre Post 1
NORM HYPOGroup (NORM, HYPO) x Period (pre, post1) = 0.017
Group (NORM, HYPO)
x Period (pre, post1) = 0.017
+3.5%p<0,05
VT2
NORM
% Change in VT2 (% VO2max)
-12
-8
-4
0
4
8
12
Pre Post 1
* *
HYPO
% Change in VT2 (% VO2max)
Pre Post 1
*
NORM HYPO
Group (NORM, HYPO) x Time (pre, post1) = 0.00032
+3.8%p<0,001
Running Performance
-7-5-3-11357
Pre Post Post 2 Pre Post Post 2
NORM HYPONS main effects (MANOVA)
• No changes in MAS in contrast with increased performance
+2.9% in 4-min trial in world-class track cyclists (IHE 15)1
+0.9% in 200-m time-trial in swimmers (IHE 10 d)2
consistent with no improvement in 100-400 m and 3 km time-trials in swimmers and runners3
1 Gore et al. (1998) J Sci Med Sport2 Rodríguez et al. (2002) IX WSBMS3 Rodríguez et al. 2007 J Appl Physiol
Field Running Performance
• NS change in VO2 max (+3.7%, p=0.2) lower than in
Runners (+5%) Hi-Lo at 2,500 m for 4 wk1
Trained climbers (+6.2%), IHE for 17 days2
Swimmers (+5.4%), IHE for 10 days3
similar toSwimmers (+3.3%), IHE for 4 wks4
• Limited scope for increase in highly endurance-trained athletes or reduced sample effect?
1 Levine & Stray-Gundersen (1997) J Appl Physiol2 Casas et al. (2000) Aviat Space Environ Med3 Rodríguez et al. (2002) IX WSBMS
4 Rodríguez et al. (2004) Med Sci Sports Exerc5 Gore et al. (1998) J Sci Med Sport
Discussion: VO2 max
• Significant increase AT1 +3.5% VT2 +3.8%
consistent with LT improvement in climbers1,2 and swimmers3
• Significant decrease VCO2max -8.7%
• Changes suggesting improvement of aerobic endurance and lower reliance on glycolitic metabolism: mechanism?
1 Rodríguez et al. 1999 Med Sci Sports Exerc2 Casas et al. 2000 Aviat Space Environ Med3 Rodríguez et al. 2007 J Appl Physiol
VT and VCO2 max
Rodríguez et al. 2007 J Appl Physiol
HYPO Swimmers
PRE-MEAN POST1 POST2
% C
hang
e in
VO
2 at V
T
-10
0
10
20
30NORM Swimmers
PRE-MEAN POST1 POST2
-3.5% [-0.7 to -6.2]p = 0.56
+8.9% [5.4 to 12.5]p = 0.007
+0.4% [-2.1 to 2.9]p = 0.98
+12.1% [7.0 to 17.2]p < 0.001
Group x Test F(1,10) = 6.80, p = 0.006
Intermittent Hypoxia Study 2003
NORMHYPO
• EPO secretion stimulated (mean=100-440%)
• No subsequent erythropoietic response1
• Changes not attributable to an increase in total Hbmas as in a double-blind study with runners and swimmers2
1 Abellán et al. 2004 Haematologica2 Gore et al. 2007 J Appl Physiol
Erythropoietic Response
• IHE combined with SL training to moderate-severe hypoxia did not improve track running performance (MAS) in triathletes
• Unlike in swimmers1, change in VO2 max were NS,
• This may be explained by limited scope for further increase in ET triathletes limited sample effect
Conclusions
1 Rodríguez et al. 1999 Med Sci Sports Exerc
• IHE significantly increased VT and decreased VCO2 max suggesting improved aerobic endurance capacity
not due to increased erythropoiesis or efficiency other adaptations (ventilatory, mitochondrial)?
• Although benefits can be expected, more research is needed to clarify the effect of IHE in endurance athletes
Conclusions
IMASInstitut Municipald’Investigació Mèdica. IMIMPharmacology Research Unit