Effects Of Moderate Altitude Training On Total Hemoglobin Mass And Hematology In World Class Sprint Cyclists

Abstract

Hematological adaptations to moderate altitude training have been described in elite endurance athletes. Altitude training has been associated with increases in total hemoglobin mass (tHb), maximum accumulated oxygen deficit and muscle buffering capacity in endurance athletes (1). However, relatively few investigations have focused on the effects of altitude training in sprint athletes. PURPOSE: To quantify the hematological response of sprint cyclists to 4wks of moderate altitude training. METHODS: The Australian Track Sprint Cycling Team (M=4; F=3) completed a 28d training camp at 1860m. Cyclists' hemoglobin concentration ([Hb]) and hematocrit (Hct) were measured pre-departure and day 25 at altitude, while body composition and tHb were determined on day 4 and day 25 of the 28d camp. The cyclists completed track training involving maximal efforts over distances ranging from 50 to 750m (∼27 hrs total), weight training (∼16 hrs total), road rides (∼18 hrs total) and cycle ergometer sessions (∼2 hrs total). Data are reported as mean±SD, paired t-test were conducted (p<0.05) and percent change from pre to post were calculated. RESULTS: There was a 4.5±2.5% increase in tHb (922.9±201.2 v 964.7±212.4 g: p=0.002), a 7.8±3.8% increase in [Hb] (152±8 v 164±6 g/L, p=0.001), and 9.2±4.4% increase in Hct (44.4±2.5 v 48.4±2.3%: p=0.001). The changes in blood volume (0.6±4.9%) and plasma volume (-2.5±7.0%) were not significant (p=0.62 and 0.42, respectively). Ferritin declined from 100±66 ug/L to 81±37 ug/L (p=0.17). Only one cyclist used oral iron supplements. There was ∼1 kg decrease in body mass (81.1±10.6 v 80.0±10.6 kg, p=0.05) without a significant change in sum of seven skinfolds (67.3±22.0 v 65.4±22.0 mm, p=0.19). CONCLUSION: Our results challenge the recommendation that ∼2200m is the minimal altitude required to increase tHb. These data extend previous altitude training research using endurance athletes (2) and demonstrate that similar gains in tHb (∼5% in 4wks) can occur in sprint cyclists who complete relatively low volume, high intensity training. Further research is required to determine the impact of these hematological changes on sprint cycling performance. 1. CJ Gore et al. Med.Sci.Sports Exerc. 39:1600-09, 2007. 2. LA Garvican et al. Med.Sci.Sports Exerc. 40:S52, 2008.