Intermittent Hypoxia Improves Endurance Performance and Submaximal Exercise Efficiency

Abstract

The purpose of the present study was to elucidate the influence of intermittent hypobaric hypoxia at rest on endurance performance and cardiorespiratory and hematological adaptations in trained endurance athletes. Twelve trained male endurance runners were assigned to either a hypoxic group (n = 6) or a control group (n = 6). The subjects in the hypoxic group were exposed to a simulated altitude of 4500 m for 90 min, three times a week for 3 weeks. The measurements of 3000 m running time, running time to exhaustion, and cardiorespiratory parameters during maximal exercise test and resting hematological status were performed before (Pre) and after 3 weeks of intermittent hypoxic exposure (Post). These measurements were repeated after the cessation of intermittent hypoxia for 3 weeks (Re). In the control group, the same parameters were determined at Pre, Post, and Re for the subjects not exposed to intermittent hypoxia. The athletes in both groups continued their normal training together at sea level throughout the experiment. In the hypoxic group, the 3000 m running time and running time to exhaustion during maximal exercise test improved. Neither cardiorespiratory parameters to maximal exercise nor resting hematological parameters were changed in either group at Post, whereas oxygen uptake (.V(O2)) during submaximal exercise decreased significantly in the hypoxic group. After cessation of intermittent hypoxia for 3 weeks, the improved 3000 m running time and running time to exhaustion tended to decline, and the decreased .V(O2) during submaximal exercise returned to Pre level. These results suggest that intermittent hypoxia at rest could improve endurance performance and submaximal exercise efficiency at sea level in trained endurance athletes, but these improvements are not maintained after the cessation of intermittent hypoxia for 3 weeks.

Acute Normobaric Hypoxia Stimulates Erythropoietin Release

“…Recently, Lundby and colleagues (2005) concluded that 120 min of hypobaric hypoxia was not great enough to cause a significant increase in EPO; yet their data produced a mean increase of 31.6%. It is at least plausible that the lack of a statistical change in EPO in the Lundby et al (2005) study and other work (Katayama et al, 2003) may have been due to error of measurement (TEM). However, this is at best speculative, as the authors did not publish these data.…”

“…Hypoxic-induced elevations in EPO and so possible increased erythropoiesis has clear tangible benefits for both athletic (Stray-Gundersen et al, 2001) and clinical (Silverberg et al, 2004;Corwin, 2004) populations. However, other investigations have failed to conclude the effectiveness of acute on intermittent hypoxia (Vallier et al, 1996;Katayama et al, 2003;Julian et al, 2004). For a review, see Wilber (2001).…”

“…The authors hypothesized that the timings of blood collection could have prevented the detection of possible changes in EPO (Katayama et al, 2003, Julian et al, 2004 and that a hypoxic-normoxic ratio of 5:5 is an insufficient stress. Garcia et al (2000) failed to witness any change in EPO following an exposure (F I O 2 ϳ 0.13; 3500 m) above what Ge et al (2002) termed the optimal threshold, and the period of exposure was continuous (120 min).…”

The effects of single versus twice daily short term heat acclimation on heat strain and 3000m running performance in hot, humid conditions

“…Consequently, for moderately trained individuals used within the study, there b b b ' merely reflect a reduction in perceived exertion and improved thermal comfort under heat stress. Previous studies investigating various interventional strategies on 3 km performance, include intermittent hypoxic (Stray-Gundersen, et al, 2001;Katayama, et al, 2003Katayama, et al, , 2004Rodriguez et al, 2007), plyometric (Spurrs et al, 2003;Pellegrino et al, 2015) and intense training periods (Smith et al, 1999;Coutts, et al, 2007;Esfarjani, et al, 2007), reporting a vast range in improvements from 0.8 to 7.3%. However, the le ' aerobic fitness level, running experience, length and method of intervention vary considerably and so comparisons to this study must be interpreted lightly.…”

Entrenamiento en hipoxia intermitente y rendimiento ciclista en triatletas / Intermittent hypoxic training and cycling performance in triathletes

“…Lo mismo sucede en el estudio de Hinckson, Hopkins, Downey y Smith (2006) en el que se aplicó un programa de 14 sesiones de 90 minutos de duración entre el 80-92% de la SpO2 en remeros. También existen otras investigaciones previas (Calbet et al, 2003;Consolazio, Nelson, Matoush & Hansen, 1996;Wolfel, Groves & Brooks, 1991;Tadibi, Dehnert, Menold & Bartsch, 2007) que utilizan la exposición a hipoxia intermitente como estímulo, donde el umbral anaeróbico no se modificó o incluso descendió trasun programa de altitud simulada (Katayama, Matsuo, Ishida, Mori & Miyamura, 2003;Lundby, Nielsen & Dela, 2005). Los resultados de nuestra investigación son compartidos por Bonetti et al (2009) que observaron un incremento del 6.5% en la potencia generada en el umbral anaeróbico de 18 triatletas y ciclistas después de 15 sesiones de 60 minutos de duración a una SpO2 del 76-90% o por Friedmann et al (2005) que observaron un incremento del 3 % en la velocidad del umbral anaeróbico tras un programa de IHE de 4 horas diarias al 15 % del FiO2 en 16 nadadores.…”