“Live high–train low” using normobaric hypoxia: a double-blinded, placebo-controlled study

Abstract

Siebenmann C, Robach P, Jacobs RA, Rasmussen P, Nordsborg N, Diaz V, Christ A, Olsen NV, Maggiorini M, Lundby C. "Live high-train low" using normobaric hypoxia: a double-blinded, placebo-controlled study. J Appl Physiol 112: 106 -117, 2012. First published October 27, 2011 doi:10.1152/japplphysiol.00388.2011The combination of living at altitude and training near sea level [live high-train low (LHTL)] may improve performance of endurance athletes. However, to date, no study can rule out a potential placebo effect as at least part of the explanation, especially for performance measures. With the use of a placebo-controlled, double-blinded design, we tested the hypothesis that LHTL-related improvements in endurance performance are mediated through physiological mechanisms and not through a placebo effect. Sixteen endurance cyclists trained for 8 wk at low altitude (Ͻ1,200 m). After a 2-wk lead-in period, athletes spent 16 h/day for the following 4 wk in rooms flushed with either normal air (placebo group, n ϭ 6) or normobaric hypoxia, corresponding to an altitude of 3,000 m (LHTL group, n ϭ 10). Physiological investigations were performed twice during the lead-in period, after 3 and 4 wk during the LHTL intervention, and again, 1 and 2 wk after the LHTL intervention. Questionnaires revealed that subjects were unaware of group classification. Weekly training effort was similar between groups. Hb mass, maximal oxygen uptake (VO 2) in normoxia, and at a simulated altitude of 2,500 m and mean power output in a simulated, 26.15-km time trial remained unchanged in both groups throughout the study. Exercise economy (i.e., VO 2 measured at 200 W) did not change during the LHTL intervention and was never significantly different between groups. In conclusion, 4 wk of LHTL, using 16 h/day of normobaric hypoxia, did not improve endurance performance or any of the measured, associated physiological variables.altitude; LHTL; performance; training OVER THE PAST FIVE DECADES, endurance athletes have attempted to improve sea-level performance by means of altitude training. In the early 1990s, Levine and Stray-Gundersen (36) introduced the "live high-train low" (LHTL) strategy, where athletes reside and spend the majority of the day at moderate altitude while training closer to sea level. This paradigm aims for athletes to benefit from physiological adaptation to hypoxia, while avoiding the detrimental impact of hypoxia on high-intensity endurance training. After an initial study had provided results indicating that LHTL enhances aerobic performance in competitive runners (34), a bulk of follow-up studies confirmed these benefits across a variety of endurance disciplines (7,50,57,59). None of them, however, used a double-blinded design, and thus it cannot be ruled out that the observed effects, especially on performance measures, were, at least in part, mediated by a placebo effect (11, 56). Our main aim with this study was therefore to investigate the effect of LHTL in a double-blinded, placebo-controlled study.A further aim was t...

Ventilatory Chemosensitivity, Cerebral and Muscle Oxygenation, and Total Hemoglobin Mass Before and After a 72-Day Mt. Everest Expedition

“…Variability is also evident when actually measuring total hemoglobin mass at moderate altitude. Siebenmann et al (2012) exposed athletes to either live-high-trainlow for 16 h daily at a simulated 3000 m or else a blinded, placebo nonhypoxic exposure and training for 4 weeks. Notably, high inter-individual variability in tHb-mass was reported in the live-high-train-low group, with five of ten exhibiting increases but three significantly decreasing tHbmass.…”

Point: Counterpoint: Hypobaric hypoxia induces/does not induce different responses from normobaric hypoxia

“…Comparing the training benefits between different hypoxic methods is difficult because changes in performance result from the combination of "hypoxic dose" and training content (19). Interestingly, most of the "living high training low (LHTL)" studies conducted in NH do not report an improvement in performance (i.e., significant difference between the experimental and control groups) (1,2,9,10,21,24,27). Interestingly, some of these normobaric LHTL studies induced a positive erythropoietic response (erythrocytes or Hb mass) (5,22,23), confirming that the red blood cell increase is likely not the only parameter involved in the performance improvement during altitude training.…”

Con: Live High–Train Low Does Not Improve Sea-Level Performance Beyond that Achieved with the Equivalent Living and Training at Sea Level

“…The primary reductionistic mechanisms put forth to explain any purported improvement in sea-level performance with LHTL have been attributed either to an increase in oxygen carrying capacity via an increase in total hemoglobin mass (nHb) Wilber et al, 2007) or to an improvement in mechanical efficiency during exercise (Gore et al, 2007). Group mean increases in nHb with LHTL have been the more consistent adaptation with LHTL (Robach and Lundby, 2012;Robertson et al, 2010), although there is marked individual variation (Chapman et al, 1998;Robertson et al, 2010;Siebenmann et al, 2012), and measurable increases are not always apparent (Neya et al, 2007;Siebenmann et al, 2012). Even a longer duration of chronic terrestrial hypoxic exposure to a higher elevation than was initially presented (Levine and Stray-Gundersen, 1997) failed to increase nHb in elite cyclists (Gore et al, 1998).…”

“…Accordingly, elite athletes, a population with an already elevated nHb (Robach and Lundby 2012), would likely need to spend even more time at a respective elevation to successfully expand nHb (Rasmussen et al, 2013). Thus, the potential for LHTL to improve oxygen carrying capacity in elite athletes lacks probability (Rasmussen et al, 2013;Robach and Lundby 2012) and reliability/ consistency (Gore et al, 1998;Neya et al, 2007;Siebenmann et al, 2012). In regards to enhanced mechanical efficiency during exercise with LHTL, while there is evidence of improved electron coupling efficiency in skeletal muscle with high-altitude acclimatization in untrained individuals , the possible extrapolation of that data into functional alterations in whole body mechanical efficiency has been invalidated (Lundby et al, 2007;Siebenmann et al, 2012).…”