@article{SperlichHahnEdeletal.2018,
  author    = {Sperlich, Billy and Hahn, Lea-Sofie and Edel, Antonia and Behr, Tino and Helmprobst, Julian and Leppich, Robert and Wallmann-Sperlich, Birgit and Holmberg, Hans-Christer},
  title     = {A 4-week intervention involving mobile-based daily 6-minute micro-sessions of functional high-intensity circuit training improves strength and quality of life, but not cardio-respiratory fitness of young untrained adults},
  series = {Frontiers in Physiology},
  volume    = {9},
  journal   = {Frontiers in Physiology},
  number    = {423},
  doi       = {10.3389/fphys.2018.00423},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176565},
  year      = {2018},
  abstract  = {The present study was designed to assess the psycho-physiological responses of physically untrained individuals to mobile-based multi-stimulating, circuit-like, multiple-joint conditioning (Circuit\(_{HIIT}\)) performed either once (1xCircuitHIIT) or twice (2xCircuit\(_{HIIT}\)) daily for 4 weeks. In this single-center, two-arm randomized, controlled study, 24 men and women (age: 25 ± 5 years) first received no training instructions for 4 weeks and then performed 4 weeks of either 1xCircuitHIIT or 2xCircuit\(_{HIIT}\) (5 men and 7 women in each group) daily. The 1xCircuitHIIT and 2xCircuit\(_{HIIT}\) participants carried out 90.7 and 85.7\% of all planned training sessions, respectively, with average heart rates during the 6-min sessions of 74.3 and 70.8\% of maximal heart rate. Body, fat and fat-free mass, and metabolic rate at rest did not differ between the groups or between time-points of measurement. Heart rate while running at 6 km⋅h\(^{-1}\) declined after the intervention in both groups. Submaximal and peak oxygen uptake, the respiratory exchange ratio and heart rate recovery were not altered by either intervention. The maximal numbers of push-ups, leg-levers, burpees, 45°-one-legged squats and 30-s skipping, as well as perception of general health improved in both groups. Our 1xCircuit\(_{HIIT}\) or 2xCircuit\(_{HIIT}\) interventions improved certain parameters of functional strength and certain dimensions of quality of life in young untrained individuals. However, they were not sufficient to enhance cardio-respiratory fitness, in particular peak oxygen uptake.},
  language  = {en}
}
@article{DuekingAchtzehnHolmbergetal.2018,
  author    = {D{\"u}king, Peter and Achtzehn, Silvia and Holmberg, Hans-Christer and Sperlich, Billy},
  title     = {Integrated framework of load monitoring by a combination of smartphone applications, wearables and point-of-care testing provides feedback that allows individual responsive adjustments to activities of daily living},
  series = {Sensors},
  volume    = {18},
  journal   = {Sensors},
  number    = {5},
  doi       = {10.3390/s18051632},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176506},
  pages     = {1632},
  year      = {2018},
  abstract  = {Athletes schedule their training and recovery in periods, often utilizing a pre-defined strategy. To avoid underperformance and/or compromised health, the external load during training should take into account the individual's physiological and perceptual responses. No single variable provides an adequate basis for planning, but continuous monitoring of a combination of several indicators of internal and external load during training, recovery and off-training as well may allow individual responsive adjustments of a training program in an effective manner. From a practical perspective, including that of coaches, monitoring of potential changes in health and performance should ideally be valid, reliable and sensitive, as well as time-efficient, easily applicable, non-fatiguing and as non-invasive as possible. Accordingly, smartphone applications, wearable sensors and point-of-care testing appear to offer a suitable monitoring framework allowing responsive adjustments to exercise prescription. Here, we outline 24-h monitoring of selected parameters by these technologies that (i) allows responsive adjustments of exercise programs, (ii) enhances performance and/or (iii) reduces the risk for overuse, injury and/or illness.},
  language  = {en}
}
@article{DuekingFussHolmbergetal.2018,
  author    = {D{\"u}king, Peter and Fuss, Franz Konstantin and Holmberg, Hans-Christer and Sperlich, Billy},
  title     = {Recommendations for assessment of the reliability, sensitivity, and validity of data provided by wearable sensors designed for monitoring physical activity},
  series = {JMIR Mhealth and Uhealth},
  volume    = {6},
  journal   = {JMIR Mhealth and Uhealth},
  number    = {4},
  doi       = {10.2196/mhealth.9341},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176202},
  pages     = {e102},
  year      = {2018},
  abstract  = {Although it is becoming increasingly popular to monitor parameters related to training, recovery, and health with wearable sensor technology (wearables), scientific evaluation of the reliability, sensitivity, and validity of such data is limited and, where available, has involved a wide variety of approaches. To improve the trustworthiness of data collected by wearables and facilitate comparisons, we have outlined recommendations for standardized evaluation. We discuss the wearable devices themselves, as well as experimental and statistical considerations. Adherence to these recommendations should be beneficial not only for the individual, but also for regulatory organizations and insurance companies.},
  language  = {en}
}
@article{DuekingHolmbergSperlich2018,
  author    = {D{\"u}king, Peter and Holmberg, Hans-Christer and Sperlich, Billy},
  title     = {The potential usefulness of virtual reality systems for athletes: a short SWOT analysis},
  series = {Frontiers in Physiology},
  volume    = {9},
  journal   = {Frontiers in Physiology},
  number    = {128},
  doi       = {10.3389/fphys.2018.00128},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176178},
  year      = {2018},
  abstract  = {No abstract available.},
  language  = {en}
}
@article{DuekingHothoHolmbergetal.2016,
  author    = {D{\"u}king, Peter and Hotho, Andreas and Holmberg, Hans-Christer and Fuss, Franz Konstantin and Sperlich, Billy},
  title     = {Comparison of Non-Invasive Individual Monitoring of the Training and Health of Athletes with Commercially Available Wearable Technologies},
  series = {Frontiers in Physiology},
  volume    = {7},
  journal   = {Frontiers in Physiology},
  number    = {71},
  doi       = {10.3389/fphys.2016.00071},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165516},
  year      = {2016},
  abstract  = {Athletes adapt their training daily to optimize performance, as well as avoid fatigue, overtraining and other undesirable effects on their health. To optimize training load, each athlete must take his/her own personal objective and subjective characteristics into consideration and an increasing number of wearable technologies (wearables) provide convenient monitoring of various parameters. Accordingly, it is important to help athletes decide which parameters are of primary interest and which wearables can monitor these parameters most effectively. Here, we discuss the wearable technologies available for non-invasive monitoring of various parameters concerning an athlete's training and health. On the basis of these considerations, we suggest directions for future development. Furthermore, we propose that a combination of several wearables is most effective for accessing all relevant parameters, disturbing the athlete as little as possible, and optimizing performance and promoting health.},
  language  = {en}
}
@article{SperlichDuekingHolmberg2017,
  author    = {Sperlich, Billy and D{\"u}king, Peter and Holmberg, Hans-Christer},
  title     = {A SWOT analysis of the use and potential misuse of implantable monitoring devices by athletes},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  number    = {629},
  doi       = {10.3389/fphys.2017.00629},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158742},
  year      = {2017},
  abstract  = {Kein Abstract vorhanden.},
  language  = {en}
}
@article{SperlichHolmberg2017,
  author    = {Sperlich, Billy and Holmberg, Hans-Christer},
  title     = {The responses of elite athletes to exercise: an all-day, 24-h integrative view is required!},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  number    = {564},
  doi       = {10.3389/fphys.2017.00564},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158655},
  year      = {2017},
  abstract  = {No abstract available.},
  language  = {en}
}
@article{DuekingHolmbergSperlich2017,
  author    = {D{\"u}king, Peter and Holmberg, Hans-Christer and Sperlich, Billy},
  title     = {Instant Biofeedback Provided by Wearable Sensor Technology Can Help to Optimize Exercise and Prevent Injury and Overuse},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  number    = {167},
  doi       = {10.3389/fphys.2017.00167},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158044},
  year      = {2017},
  language  = {en}
}
@article{BornHolmbergGoernetetal.2014,
  author    = {Born, Dennis-Peter and Holmberg, Hans-Christer and Goernet, Florian and Sperlich, Billy},
  title     = {A novel compression garment with adhesive silicone stripes improves repeated sprint performance - a multi-experimental approach on the underlying mechanisms},
  series = {BMC Sports Science, Medicine and Rehabilitation},
  volume    = {6},
  journal   = {BMC Sports Science, Medicine and Rehabilitation},
  number    = {21},
  issn      = {2052-1847},
  doi       = {10.1186/2052-1847-6-21},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120591},
  year      = {2014},
  abstract  = {Background Repeated sprint performance is determined by explosive production of power, as well as rapid recovery between successive sprints, and there is evidence that compression garments and sports taping can improve both of these factors. Methods In each of two sub-studies, female athletes performed two sets of 30 30-m sprints (one sprint per minute), one set wearing compression garment with adhesive silicone stripes (CGSS) intended to mimic taping and the other with normal clothing, in randomized order. Sub-study 1 (n = 12) focused on cardio-respiratory, metabolic, hemodynamic and perceptual responses, while neuronal and biomechanical parameters were examined in sub-study 2 (n = 12). Results In both sub-studies the CGSS improved repeated sprint performance during the final 10 sprints (best P < 0.01, d = 0.61). None of the cardio-respiratory or metabolic variables monitored were altered by wearing this garment (best P = 0.06, d = 0.71). Also during the final 10 sprints, rating of perceived exertion by the upper leg muscles was reduced (P = 0.01, d = 1.1), step length increased (P = 0.01, d = 0.91) and activation of the m. rectus femoris elevated (P = 0.01, d = 1.24), while the hip flexion angle was lowered throughout the protocol (best P < 0.01, d = 2.28) and step frequency (best P = 0.34, d = 0.2) remained unaltered. Conclusion Although the physiological parameters monitored were unchanged, the CGSS appears to improve performance during 30 30-m repeated sprints by reducing perceived exertion and altering running technique.},
  language  = {en}
}
@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{BornHolmbergGoernertetal.2014,
  author    = {Born, Dennis-Peter and Holmberg, Hans-Christer and Goernert, Florian and Sperlich, Billy},
  title     = {A novel compression garment with adhesive silicone stripes improves repeated sprint performance - a multi-experimental approach on the underlying mechanisms},
  series = {BMC Sports Science, Medicine and Rehabilitation},
  volume    = {6},
  journal   = {BMC Sports Science, Medicine and Rehabilitation},
  number    = {21},
  doi       = {doi:10.1186/2052-1847-6-21},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116995},
  year      = {2014},
  abstract  = {Background Repeated sprint performance is determined by explosive production of power, as well as rapid recovery between successive sprints, and there is evidence that compression garments and sports taping can improve both of these factors. Methods In each of two sub-studies, female athletes performed two sets of 30 30-m sprints (one sprint per minute), one set wearing compression garment with adhesive silicone stripes (CGSS) intended to mimic taping and the other with normal clothing, in randomized order. Sub-study 1 (n = 12) focused on cardio-respiratory, metabolic, hemodynamic and perceptual responses, while neuronal and biomechanical parameters were examined in sub-study 2 (n = 12). Results In both sub-studies the CGSS improved repeated sprint performance during the final 10 sprints (best P < 0.01, d = 0.61). None of the cardio-respiratory or metabolic variables monitored were altered by wearing this garment (best P = 0.06, d = 0.71). Also during the final 10 sprints, rating of perceived exertion by the upper leg muscles was reduced (P = 0.01, d = 1.1), step length increased (P = 0.01, d = 0.91) and activation of the m. rectus femoris elevated (P = 0.01, d = 1.24), while the hip flexion angle was lowered throughout the protocol (best P < 0.01, d = 2.28) and step frequency (best P = 0.34, d = 0.2) remained unaltered. Conclusion Although the physiological parameters monitored were unchanged, the CGSS appears to improve performance during 30 30-m repeated sprints by reducing perceived exertion and altering running technique.},
  language  = {en}
}