Control of erythropoiesis in humans during prolonged exposure to the altitude of 6,542 m

Richalet, Jean‐Paul; Souberbielle, J.-C.; Antezana, A. M.; Déchaux, M; Trong, J. L. Le; Bienvenu, Annick; Daniel, Filipe Ivan; Blanchot, Caroline; Zittoun, J

doi:10.1152/ajpregu.1994.266.3.r756

Cited by 72 publications

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“…Interestingly, both erythropoietin concentrations (Jelkman, 1992;Richalet et al, 1993;Gunga et al, 1996;Levine and Stray-Gundersen, 1997;Chapman et al, 1998), as well as iron turnover (Huff et al, 1951;Reynafarje et al, 1959) return to sea-level values relatively rapidly with chronic altitude exposure. However, the red cell mass continues to increase for up to 8 months of chronic altitude exposure, at least at altitudes above 4000 m (Reynafarje et al, 1959) (Fig.…”

Section: Erythropoietic Effect Of High Altitudementioning

confidence: 99%

“…Moreover, despite the apparently normal EPO levels and iron turnover, it is important to point out that this level of stimulated erythropoiesis is elevated for the absolute level of the arterial oxygen content. Thus, when altitude natives, or even altitude sojourners, return to sea level, there is a suppression of erythropoietin (Faura et al, 1969;Jelkman, 1992;Richalet et al, 1993;Gunga et al, 1996;Levine and Stray-Gundersen, 1997;Chapman et al, 1998), a dramatic reduction in iron turnover and bone marrow production of erythroid cell lines (Huff et al, 1951;Reynafarje et al, 1959), and a marked decrease in red cell survival time (Reynafarje et al, 1959). This increase in red cell destruction with suppression of EPO levels has been termed neocytolysis and has been observed under other conditions of a relative increase in oxygen content (Alfrey et al, 1996a(Alfrey et al, , 1996b(Alfrey et al, , 1997Rice and Alfrey, 2000;Rice et al, 2001).…”

Section: Erythropoietic Effect Of High Altitudementioning

confidence: 99%

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Intermittent Hypoxic Training: Fact and Fancy

Levine

2002

High Altitude Medicine & Biology

161

142

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LTITUD E TRAINING has been used frequently by endurance athletes to enhance performance. However, not all athletes or teams have the resources to travel to high altitude environments on a regular basis. Moreover, issues such as availability of adequate training facilities have limited the use of mountain-based altitude training. In the last few years, there has been a remarkable increase in the number of techniques designed to "bring the mountain to the athlete." Nitrogen houses, hypoxia tents, and special breathing apparatuses to provide inspired hypoxia at rest and during exercise, all have been developed and promoted to simulate what are perceived as the critical elements of altitude training.Intermittent hypoxic training (IHT) refers to the discontinuous use of normobaric or hypobaric hypoxia, in an attempt to reproduce some of these key features of altitude acclimatization, with the ultimate goal to improve sea-level athletic performance. In general, IHT can be divided into two different strategies: (1) providing hypoxia at rest with High Alt Med Biol. 3:177-193, 2002.-Intermittent hypoxic training (IHT) refers to the discontinuous use of normobaric or hypobaric hypoxia, in an attempt to reproduce some of the key features of altitude acclimatization, with the ultimate goal to improve sea-level athletic performance. In general, IHT can be divided into two different strategies: (1) providing hypoxia at rest with the primary goal being to stimulate altitude acclimatization or (2) providing hypoxia during exercise, with the primary goal being to enhance the training stimulus. Each approach has many different possible application strategies, with the essential variable among them being the "dose" of hypoxia necessary to achieve the desired effect. One approach, called living high-training low, has been shown to improve sea-level endurance performance. This strategy combines altitude acclimatization (2500 m) with low altitude training to ensure high-quality training. The opposite strategy, living low-training high, has also been proposed by some investigators. The primacy of the altitude acclimatization effect in IHT is demonstrated by the following facts: (1) living high-training low clearly improves performance in athletes of all abilities, (2) the mechanism of this improvement is primarily an increase in erythropoietin, leading to increased red cell mass, V O 2max , and running performance, and (3) rather than intensifying the training stimulus, training at altitude or under hypoxia leads to the opposite effect-reduced speeds, reduced power output, reduced oxygen flux-and therefore is not likely to provide any advantage for a well-trained athlete.

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Section: Erythropoietic Effect Of High Altitudementioning

confidence: 99%

Section: Erythropoietic Effect Of High Altitudementioning

confidence: 99%

Intermittent Hypoxic Training: Fact and Fancy

Levine

2002

High Altitude Medicine & Biology

161

142

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“…Human studies, for example, have reported no change (Klausen et al, 1991) or even a drop (Richalet et al, 1994) in MCHC with hypoxia-induced increases in blood EPO level. Though plasma osmolality was not recorded in this study, it is possible that changes in this variable may have contributed to the observed differences in MCHC between 'surface swimmers' and 'divers'.…”

Section: Dive Conditioning and Body Oxygen Reservesmentioning

confidence: 99%

Diving experience and the aerobic dive capacity of muskrats: does training produce a better diver?

MacArthur

Weseen

Campbell

2003

Journal of Experimental Biology

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SUMMARY We tested the hypothesis that the body oxygen stores, aerobic dive limit(ADL) and dive performance of muskrats can be enhanced by dive-conditioning in a laboratory setting. We compared several key variables in 12 muskrats trained to swim a 16 m underwater course to a feeding station (`divers') with those of 12 animals precluded from diving but required to travel identical distances in water to feed (`surface swimmers'). Acclimated muskrats assigned to each group were trained concurrently over a 9–11 week period. We observed significant gains in the haematocrit (P=0.0005) and blood haemoglobin concentration (P=0.015) of `divers', but not `surface swimmers'. The post-training blood O2 store calculated for `divers' (22.9 ml O2 kg–1) was nearly 26% higher than that (18.2 ml O2 kg–1) derived for `surface swimmers'(P=0.03). Dive-conditioning had no apparent effect on lung volume,whole blood and plasma volumes, nor on the glycogen level and buffering capacity of skeletal muscles. Cardiac and skeletal muscle myoglobin levels were also similar in both test groups following training. The mean total body oxygen store of `divers' (37.8ml O2 STPD kg–1) was 13.5% higher (P=0.037) than for `surface swimmers' (33.3 ml O2 STPD kg–1), an increase attributed entirely to the gain in blood O2 storage capacity of the former group. However,owing to a slightly higher estimate of diving metabolic rate in dive-conditioned animals, the calculated ADL for this group (61.3 s) was indistinguishable from that of `surface swimmers' (61.8 s). Few differences were observed in the post-training dive behaviour of `surface swimmers' and`divers', a finding consistent with the strong similarity in their calculated aerobic dive capacities.

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“…2 3 During a 3 week sojourn at high altitude (6542 m) the increase in EPO and the subsequent haemoglobin response to EPO were both found to vary considerably. 2 More recently, Ge et al 3 reported a marked individual variability in EPO increase after 6 and 24 h exposure to hypobaric hypoxia equivalent to altitudes of 1780-2800 m. Furthermore, they concluded that altitudes >2100-2500 m might be a threshold for the induction of increased erythropoiesis in most athletes.…”

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confidence: 98%

Individual variation in the erythropoietic response to altitude training in elite junior swimmers

Friedmann

2005

Br J Sports Med

114

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Objectives: Inter-individual variations in sea level performance after altitude training have been attributed, at least in part, to an inter-individual variability in hypoxia induced erythropoiesis. The aim of the present study was to examine whether the variability in the increase in total haemoglobin mass after training at moderate altitude could be predicted by the erythropoietin response after 4 h exposure to normobaric hypoxia at an ambient Po 2 corresponding to the training altitude. Methods: Erythropoietin levels were measured in 16 elite junior swimmers before and after 4 h exposure to normobaric hypoxia (Fio 2 0.15, ,2500 m) as well as repeatedly during 3 week altitude training (2100-2300 m). Before and after the altitude training, total haemoglobin mass (CO rebreathing) and performance in a stepwise increasing swimming test were determined. Results: The erythropoietin increase (10-185%) after 4 h exposure to normobaric hypoxia showed considerable inter-individual variation and was significantly (p,0.001) correlated with the acute erythropoietin increase during altitude training but not with the change in total haemoglobin mass (significant increase of ,6% on average). The change in sea level performance after altitude training was not related to the change in total haemoglobin mass. Conclusions:The results of the present prospective study confirmed the wide inter-individual variability in erythropoietic response to altitude training in elite athletes. However, their erythropoietin response to acute altitude exposure might not identify those athletes who respond to altitude training with an increase in total haemoglobin mass.

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Control of erythropoiesis in humans during prolonged exposure to the altitude of 6,542 m

Cited by 72 publications

References 0 publications

Intermittent Hypoxic Training: Fact and Fancy

Intermittent Hypoxic Training: Fact and Fancy

Diving experience and the aerobic dive capacity of muskrats: does training produce a better diver?

Individual variation in the erythropoietic response to altitude training in elite junior swimmers

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