Longitudinal changes in haemoglobin mass and VO2max in adolescents

This study assessed the relationship between haemoglobin mass (Hb_mass) and maximum oxygen consumption (VO_2max) in adolescents over 1 year. Twenty-three subjects (11-15 years) participated; 12 undertook ∼12 months of cycle training (cyclists) and 11 were sedentary (controls). Hb_mass and VO_2max were measured approximately every 3 months. At baseline there was a high correlation (r = 0.82, P< 0.0001) between relative VO_2max (ml kg^-1 min^-1) and relative Hb_mass (g kg^-1). During 12 months there was a significant increase in relative VO_2max of the cyclists but not the controls; however, there was no corresponding increase in relative Hb_mass of either group. The correlation between percent changes in relative VO_2max and relative Hb_mass was not significant for cyclists (r = 0.31, P = 0.33) or controls (r = 0.42, P = 0.19). Training does not increase relative Hb_mass in adolescents consistent with a strong hereditary role for Hb_mass and VO_2max. Hb_mass may be used to identify adolescents who have a high VO_2max.