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The Time course of the Erythropoietic Response to Natural Altitude Training in Elite Endurance Cyclists: 738May 29 2:15 PM - 2:30 PM

Garvican, Laura A.1; Martin, David T.1; Clark, Melissa A.1; Quod, Marc1; Stephens, Brian1; Prommer, Nicole2; Schmidt, Walter F. FACSM2; Impellizzeri, Franco M.3; Rampinini, Ermanno3; Sassi, Aldo3; Gore, Christopher J. FACSM1

Medicine & Science in Sports & Exercise: May 2008 - Volume 40 - Issue 5 - p S52
doi: 10.1249/01.mss.0000321672.78284.55
D-11 Free Communication/Slide - Altitude and Hypoxia: MAY 29, 2008 1:00 PM - 2:30 PM ROOM: 122

1Australian Institute of Sport, Belconnen, ACT, Australia. 2University of Bayreuth, Bayreuth, Germany. 3Mapei Sports Research Centre, Castellanza, Italy.


(No relationships reported)

Erythropoietin (EPO) induced increases in total haemoglobin mass (tHb) are generally thought to explain improvements in endurance performance following 3-4 wks of altitude training. However, the time course of the tHb response to natural altitude in endurance athletes is not well documented.

PURPOSE: To identify when the greatest gains in tHb occur during 3 wks of natural altitude training in elite endurance cyclists.

METHODS: tHb (CO re-breathing), [EPO], reticulocytes, and soluble transferrin receptor (sTfr) were measured throughout 21 nights of structured training in 13 internationally competitive cyclists preparing for the World Championships (Mean±SD Mass, Age, VO2max: 67.9±6.0 kg, 21.0±1.5 y, 73.7±6.1−1.min−1). Eight cyclists (ALT) lived at 2760m and trained for 3-6 h.d−1 at 1000-2760m. Five cyclists (SL) lived and trained at ∼600m. All cyclists completed similar training (600-900 km.wk−1; low intensity with frequent climbing 10,000-15,000 m.wk−1). Duplicate measures for all dependent variables were performed at baseline (D0). Daily iron supplementation (305mg ferrous sulphate + 1000mg Vitamin C) was administered for 1-2 wks prior to and during the study.

RESULTS: Typical Error for tHb was 1.6% (ALT) and 1.8% (SL). tHb at D0 (ALT 946±67 g; SL 991±96 g) increased for ALT (Mean±90%CI; D6 1.2±1.2%, p=.12; D11 2.9%±1.2, p=.01; D19 3.5%±1.6, p=.01; D23 2.0%±1.6, p=.07) but not for SL. [EPO] increased from D0 (15.4±4.0−1) in ALT (D2 66.2%±17.3, p<0.001) but returned to D0 values by D12. [EPO] did not increase in SL. Reticulocytes (%) increased slightly from D0 (0.9% ± 0.2 - absolute value) in ALT (D5 20.3%±11.3 p=.02; D12 23.1%±15.7, p=.05 - relative changes) but were not different than D0 by D20 (p=.57). For ALT, sTfr was higher than D0 (2.9±0.5mg.l−1) at D12 (19.9%±9.9, p=.01) but not different from D0 at D20 (13.2%±11.3, p=.1). For SL, sTfr was only elevated from D0 at D21 (10.3%±4.7, p=.03)

CONCLUSIONS: The greatest gains in tHb in this study occurred over the first 11 d of altitude training. tHb did not noticeably increase with an additional 10 d of exposure. The signal for erythropoiesis appears to be attenuated after ∼12 d as reflected by [EPO], sTfr and reticulocytes. In this instance, we observed that the final week of altitude exposure elicited little benefit on tHb.

©2008The American College of Sports Medicine