A new dose of maximal-intensity interval training in hypoxia to improve body composition and hemoglobin and hematocrit levels: a pilot study.

BACKGROUND: This pilot study had the aim to determine the effects of a new dose of maximal-intensity interval training in hypoxia in active adults.

METHODS: Twenty-four university student volunteers were randomly assigned to three groups: hypoxia group, normoxia group or control group. The eight training sessions consisted of 2 sets of 5 repeated sprints of 10 seconds with a recovery of 20 seconds between sprints and a recovery period of 10 minutes between sets. Body composition was measured following standard procedures. A blood sample was taken for an immediate hematocrit (HCT) and hemoglobin (Hb) concentration assessment. An all-out 3-ute test was performed to evaluate ventilation parameters and power.

RESULTS: HCT and Hb were significantly higher for the hypoxia group in Post- and Det- (P=0.01; P=0.03). Fat mass percentage was significantly lower for the hypoxia group in both assessments (P=0.05; P=0.05). The hypoxia group underwent a significant increase in mean power after the recovery period.

CONCLUSIONS: A new dose of 8 sessions of maximal-intensity interval training in hypoxia is enough to decrease the percentage of fat mass and to improve HCT and Hb parameters and mean muscle power in healthy and active adults.