From that point of view and considering 1) the relationship between oxygenation, muscle energetics and muscle function (including fatigue) (Woodson et al., 1978; Haseler et al., 1999), 2) the potential beneficial effects of HU on Hb level and local blood flow previously reported (Fucharoen et al., 1996; Cokic et al., 2003; Green and Barral, 2014), one could expect that a chronic HU supplementation could improve muscle energetics and function even in mild anemia. The gene discussed is GSTM1; the disease is anemia (phenotype).