@article{ZinnerHauserBornetal.2015,
  author    = {Zinner, Christoph and Hauser, Anna and Born, Dennis-Peter and Wehrlin, Jon P. and Holmberg, Hans-Christer and Sperlich, Billy},
  title     = {Influence of Hypoxic Interval Training and Hyperoxic Recovery on Muscle Activation and Oxygenation in Connection with Double-Poling Exercise},
  series = {PLoS One},
  volume    = {10},
  journal   = {PLoS One},
  number    = {10},
  doi       = {10.1371/journal.pone.0140616},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126299},
  pages     = {e0140616},
  year      = {2015},
  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 \((Ho; F_iO_2 = 0.165)\). In the third and fourth trials, the exercise was performed in normoxia and hypoxia, respectively, with hyperoxic recovery \((HOX; F_iO_2 = 1.00)\) 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' \(P_{mean}\) 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 \(P_{mean}\) 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 \((F_iO_2 = 1.00)\) used in conjunction with hypoxic or normoxic work intervals may serve as an effective aid when inhaled during the subsequent recovery intervals.},
  language  = {en}
}
@article{ZinnerBornSperlich2017,
  author    = {Zinner, Christoph and Born, Dennis-Peter and Sperlich, Billy},
  title     = {Ischemic preconditioning does not alter performance in multidirectional high-intensity intermittent exercise},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  doi       = {10.3389/fphys.2017.01029},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159348},
  pages     = {1029},
  year      = {2017},
  abstract  = {Purpose: Research dealing with ischemic preconditioning (IPC) has primarily focused on variables associated to endurance performance with little research about the acute responses of IPC on repeated multidirectional running sprint performance. Here we aimed to investigate the effects of IPC of the arms and the legs on repeated running sprint performance with changes-of-direction (COD) movements. Methods: Thirteen moderately-to-well-trained team-sport athletes (7 males; 6 females; age: 24 ± 2 years, size: 175 ± 8 cm, body mass: 67.9 ± 8.1 kg) performed 16 × 30 m all-out sprints (15 s rest) with multidirectional COD movements on a Speedcourt\(^{©}\) with IPC (3 × 5 min) of the legs (IPC\(_{leg}\); 240 mm Hg) or of the arms (remote IPC: IPC\(_{remote}\); 180-190 mm Hg) 45 min before the sprints and a control trial (CON; 20 mm Hg). Results: The mean (±SD) time for the 16 × 30 m multidirectional COD sprints was similar between IPC\(_{leg}\) (Mean t: 16.0 ± 1.8 s), IPC\(_{remote}\) (16.2 ± 1.7 s), and CON (16.0 ± 1.6 s; p = 0.50). No statistical differences in oxygen uptake (mean difference: 0\%), heart rate (1.1\%) nor muscle oxygen saturation of the vastus lateralis (4.7\%) and biceps brachii (7.8\%) between the three conditions were evident (all p > 0.05). Conclusions: IPC (3 × 5 min) of the legs (220 mm Hg) or arms (180-190 mm Hg; remote IPC) applied 45 min before 16 × 30 m repeated multidirectional running sprint exercise does not improve sprint performance, oxygen uptake, heart rate nor muscle oxygen saturation of the vastus lateralis muscle when compared to a control trial.},
  language  = {en}
}