Hemoglobin mass and performance responses during 4 weeks of normobaric “live high–train low and high”

Purpose To investigate whether 4 weeks of normobaric “live high–train low and high” (LHTLH) causes different hematological, cardiorespiratory, and sea-level performance changes compared to living and training in normoxia during a preparation season. Methods Nineteen (13 women, 6 men) cross-country skiers competing at the national or international level completed a 28-day period (∼18 h day−1) of LHTLH in normobaric hypoxia of ∼2400 m (LHTLH group) including two 1 h low-intensity training sessions per week in normobaric hypoxia of 2500 m while continuing their normal training program in normoxia. Hemoglobin mass (Hbmass) was assessed using a carbon monoxide rebreathing method. Time to exhaust…