Effects Of Repetitive Training At Low Altitude On Erythropoiesis In Elite 400m And 800m Runners

Abstract

Classical altitude training was shown to cause an increase in total body hemoglobin (THB) if a certain "dose of hypoxia" is reached (moderate altitude ≥2000 m, duration ≥3 weeks). PURPOSE: To find out if already at low altitude an increase in erythropoiesis and in TBH can be induced when repetitive training camps are used. METHODS: 8 elite 400 m and 800 m runners (4 males, 4 females, 22.6±2.6 yrs, 180±11.2 cm, 67.6±11.4 kg) performed training camps in South Africa (1300 m) and Namibia (1650 m) for 20 and 22 days, interspersed by 19 days of sea-level training. A control group (CG) of 9 young well-trained runners (6 males, 3 females, 19.7±2.4 yrs, 178±5.7 cm, 66.3±11.2kg) performed comparable sea-level training. TBH was determined with the optimised CO-rebreathing method (typical error 2.5% in our hands) before and after each training camp as well as Erythropoietin (EPO), soluble Transferrin Receptor (sTfR) and Ferritin from venous blood samples. In the altitude training group (AG) EPO, sTfR and Ferritin were also repeatedly measured during the training camps. Athletes with low ferritin values received iron supplementation. RESULTS: Repeated Measures ANOVA revealed a significant (p = 0.05) increase in THB by 5.1% (0.2-13.6%) from 806±214 g to 850±235 g in the course of the 2 altitude training camps while THB remained unchanged in CG (from 770±126 g to 798±140 g, p = 0.243). During training in South Africa, EPO was significantly (p = 0.05) increased by 28% on days 10 and 17 compared to the value measured before altitude training, while in Namibia, EPO was significantly increased by 33-45% on days 2, 10 and 17 compared to the values measured after altitude training. STfR was significantly (p = 0.05) increased on day 17 of both altitude training camps by about 24% and after the training camps by about 8% while ferritin significantly decreased at the beginning of the first altitude training camp and remained slightly decreased compared to the value before altitude training. In CG, a slight, but significant decrease in sTfR was observed at the end of the study, while ferritin remained unchanged. CONCLUSION: Repetitive training at low altitude (1300-1650 m) induces an increase in erythropoiesis and, apparently, might also cause a consecutive augmentation of TBH. Supported by the Bundesinstitut für Sportwissenschaft (HA1VF070106/07)