Relationship between total hemoglobin mass and competitive performance in endurance athletes

BACKGROUND: Determine the relationships between total hemoglobin mass (tHb-mass), h emoglobin (Hb), hematocrit (Hct) and competitive performance. METHODS: The team of 35 elite endurance athletes (biathlon men [BM, N.=12] & women [BW, N.=10], long track speed-skating men [SM, N.=7] and women [SW, N.=6]) were examined before participate in seven different competitions (C1 through C7) during the 2012-2013 and 2013-2014 seasons. Total hemoglobin mass measurement and biochemical analysis were performed using carbon monoxide rebreathing technique 24 hours before the competition. RESULTS: In BM correlations were found between results of two 10-km sprint competitions and tHb-mass between C1 and C2 (r=-0.94 and r=-0.87). Correlations were also found between tHb-mass and performance in C3 individual races for BM (16.765 km, r=-0.88; and 10-km sprint, r=0.80) and BW (7.2 km, r=-0.79; and 10-km sprint, r=-0.81). In SM, a correlation was found between tHb-mass and performance (r=-0.83) in C5. In SM and SW correlations were seen between tHb-mass and performance (SM, 5,000-m; r=-0.80; SW, 3,000-m; r=-0.77) in C6. CONCLUSIONS: No correlation was found between performance and Hb or Hct in any group. The demonstration of significant and direct correlation between tHb-mass and competitive performance highlights the importance of tHb-mass in this context and may be relevant for coaches providing one more piece of information for training.