Erythropoiesis and Performance after Two Weeks of Living High and Training Low in Well Trained Triathletes

Abstract

The purpose of our study was to evaluate hematologic acclimatization during 2 weeks of intensive normoxic training with regeneration at moderate altitude (living high-training low, LHTL) and its effects on sea-level performance in well trained athletes compared to another group of equally trained athletes under control conditions (living low - training low, CONTROL). Twenty-one triathletes were ascribed either to LHTL (n = 11; age: 23.0 +/- 4.3 yrs; VO 2 max: 62.5 +/- 9.7 [ml x min -1 x kg -1]) living at 1956 m of altitude or to CONTROL (n = 10; age: 18.7 +/- 5.6 yrs; VO 2 max: 60.5 +/- 6.7 ml x min -1 x kg -1) living at 800 m. Both groups performed an equal training schedule at 800 m. VO 2 max, endurance performance, erythropoietin in serum, hemoglobin mass (Hb tot, CO-rebreathing method) and hematological quantities were measured. A tendency to improved performance in LHTL after the camp was not significant (p < 0.07). Erythropoietin concentration increased temporarily in LHTL (Delta 14.3 +/- 8.7 mU x ml -1; p < 0.012). Hb tot remained unchanged in LHTL whereas was slightly decreased from 12.5 +/- 1.3 to 11.9 +/- 1.3g x kg -1 in CONTROL (p < 0.01). As the reticulocyte number tended to higher values in LHTL than in CONTROL, it seems that a moderate stimulation of erythropoiesis during regeneration at altitude served as a compensation for an exercise-induced destruction of red cells.

Living high–training low: effect on erythropoiesis and aerobic performance in highly-trained swimmers

“…Subjects were control (n=9) and LHTL swimmers (n=9). Iron intake was recorded daily (see Methods) before (PRE), over 5 days at simulated altitude of 2,500 m and 8 days at simulated altitude of 3,000 m, and over the first (R-1) and second week (R-2) after 13 days of LHTL blood cell volume after 28 nights at 2,500 m (Levine and Stray-Gundersen 1997), but differed from other works, showing an absence of change in red blood cell volume after 12 nights at 2,650 m (Ashenden et al 1999a), 23 nights at 3,000 m (Ashenden et al 1999b), or 14 nights at 1,956 m (Dehnert et al 2002). Among the reasons accounting for these conflicting results in the literature, the daily exposure to hypoxia appears to be a critical factor; whereas an exposure of 8-10 h day À1 did not enhance red blood cell volume, independent of the total number of consecutive nights (Ashenden et al 1999a, b) longer exposure (16-20 h day À1 ) was associated with a rise in red blood cell volume (Levine 2002).…”

“…Among the reasons accounting for these conflicting results in the literature, the daily exposure to hypoxia appears to be a critical factor; whereas an exposure of 8-10 h day À1 did not enhance red blood cell volume, independent of the total number of consecutive nights (Ashenden et al 1999a, b) longer exposure (16-20 h day À1 ) was associated with a rise in red blood cell volume (Levine 2002). Finally, in spite of a daily exposure to hypoxia of 13 h, Dehnert et al (2002) did not find an increase in red blood cell volume, probably because the hypoxic stimulus used in Values are means ± SD. Subjects were control (n=9) and LHTL swimmers ( , before (PRE), 1-2 days after (POST-1) and 2 weeks (POST-15) after a 13-day period of LHTL.…”

Time course of haemoglobin mass during 21 days live high:train low simulated altitude

“…org/resource/stats/xcrossover.xls), which is based on the paired t statistic, was used to analyse Hb mass , VO 2max , and sEPO. The smallest worthwhile change for sEPO was adopted from the Cohen's (1988) classification system that a small effect size is C0.2, whereas the smallest worthwhile change of 1% was adopted for both Hb mass and VO 2max . A modification of Cohen's effect size classification system (trivial 0.0-0.2; small 0.2-0.6; moderate 0.6-1.2; large 1.2-2.0) was used to interpret the magnitude of the change in the mean.…”

“…3 The increase in red cell volume (RCV) or haemoglobin mass (Hb mass ) as a linear function (and 95% confidence limits) of total hours of hypoxic exposure for 15 Live High:Train Low studies (Ashenden et al 1999a, b;Brugniaux et al 2006;Dehnert et al 2002;Laitinen et al 1995;Levine and Stray-Gundersen 1997;Myhre et al 2003;Neya et al 2007;Piehl-Aulin et al 1998;Saunders et al 2009;Robach et al 2006a, b;Rusko et al 1999; Eur J Appl Physiol (2009) 106:399-406 403 treatments that do not exceed 12 h/day or a total of 300 h ). The optimal duration of LHTL, or other moderate altitude modalities, is unknown since the rate of 1% per week is unlikely to continue indefinitely before a plateau is achieved.…”

Acute Normobaric Hypoxia Stimulates Erythropoietin Release

“…Knaupp et al (1992) Rusko et al (1995); Mattila and Rusko, (1996);Chapman et al (1998);Piehl-Aulin et al (1998); Rusko et al (1999); Ashenden et al (2000); Koistinen et al (2000); StrayGundersen et al (2001);Ge et al (2002);Friedmann et al (2005) Ն3800 m (F IO2 ϳ0.135) Eckardt et al (1989); Knaupp et al Vallier et al (1996);Garcia et (1992); Savourey et al (1996);al. (2000); Katayama et al Rodriguez et al (2000); Niess et al (2003); Julian et al (2004); ( Rusko et al (1995); Mattila and Rusko (1996); Savourey et al (1996); Chapman et al (1998);Piehl-Aulin et al (1998a);Piehl-Aulin et al (1998b); Rusko et al (1999); Ashenden et al (2000); Koistinen et al (2000); Stray-Gundersen et al (2001); Dehnert et al (2002); Ge et al (2002) brecht and Littell, 1972;Eckardt et al, 1989). However, most studies have used exposure times greater than 2 h ( Table 1).…”