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

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