title: Influence of Hypoxic Interval Training and Hyperoxic Recovery on Muscle Activation and Oxygenation in Connection with Double-Poling Exercise.
abstract: Here, we evaluated the influence of breathing oxygen at different partial pressures during recovery from exercise on performance at sea-level and a simulated altitude of 1800 m, as reflected in activation of different upper body muscles, and oxygenation of the m. triceps brachii. Ten well-trained, male endurance athletes (25.3±4.1 yrs; 179.2±4.5 cm; 74.2±3.4 kg) performed four test trials, each involving three 3-min sessions on a double-poling ergometer with 3-min intervals of recovery. One trial was conducted entirely under normoxic (No) and another under hypoxic conditions (Ho; FiO2 = 0.165). In the third and fourth trials, the exercise was performed in normoxia and hypoxia, respectively, with hyperoxic recovery (HOX; FiO2 = 1.00) in both cases. Arterial hemoglobin saturation was higher under the two HOX conditions than without HOX (p<0.05). Integrated muscle electrical activity was not influenced by the oxygen content (best d = 0.51). Furthermore, the only difference in tissue saturation index measured via near-infrared spectroscopy observed was between the recovery periods during the NoNo and HoHOX interventions (P<0.05, d = 0.93). In the case of HoHo the athletes' Pmean declined from the first to the third interval (P < 0.05), whereas Pmean was unaltered under the HoHOX, NoHOX and NoNo conditions. We conclude that the less pronounced decline in Pmean during 3 x 3-min double-poling sprints in normoxia and hypoxia with hyperoxic recovery is not related to changes in muscle activity or oxygenation. Moreover, we conclude that hyperoxia (FiO2 = 1.00) used in conjunction with hypoxic or normoxic work intervals may serve as an effective aid when inhaled during the subsequent recovery intervals.
authors.affiliation: Department of Sport Science, Julius-Maximilians-University Würzburg, Würzburg, Germany; Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.
authors.forename: Christoph
authors.initials: C
authors.lastname: Zinner
authors.affiliation: Swiss Federal Institute of Sport, Section for Elite Sport, Magglingen, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Hauser
authors.affiliation: Department of Sport Science, Julius-Maximilians-University Würzburg, Würzburg, Germany.
authors.forename: Dennis-Peter
authors.initials: DP
authors.lastname: Born
authors.affiliation: Swiss Federal Institute of Sport, Section for Elite Sport, Magglingen, Switzerland.
authors.forename: Jon P
authors.initials: JP
authors.lastname: Wehrlin
authors.affiliation: Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.
authors.forename: Hans-Christer
authors.initials: HC
authors.lastname: Holmberg
authors.affiliation: Department of Sport Science, Julius-Maximilians-University Würzburg, Würzburg, Germany; Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.
authors.forename: Billy
authors.initials: B
authors.lastname: Sperlich
mesh_terms: D000328:Adult; D000531:Altitude; D015687:Cell Hypoxia; D006452:Hemoglobinometry; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D010313:Partial Pressure; D010807:Physical Endurance / Q000502:physiology*; D012119:Respiration; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult