@article{SperlichWallmannSperlichZinneretal.2017,
  author    = {Sperlich, Billy and Wallmann-Sperlich, Birgit and Zinner, Christoph and Von Stauffenberg, Valerie and Losert, Helena and Holmberg, Hans-Christer},
  title     = {Functional High-intensity Circuit Training Improves Body Composition,Peak Oxygen Uptake, Strength, and Alters Certain Dimensions of Quality of Life in Overweight Women},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  number    = {172},
  doi       = {10.3389/fphys.2017.00172},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171015},
  year      = {2017},
  abstract  = {The effects of circuit-like functional high-intensity training (Circuit\(_{HIIT}\)) alone or in combination with high-volume low-intensity exercise (Circuit\(_{combined}\)) on selected cardio-respiratory and metabolic parameters, body composition, functional strength and the quality of life of overweight women were compared. In this single-center, two-armed randomized, controlled study, overweight women performed 9-weeks (3 sessions·wk\(^{-1}\)) of either Circuit\(_{HIIT}\) (n = 11), or Circuit\(_{combined}\) (n = 8). Peak oxygen uptake and perception of physical pain were increased to a greater extent (p < 0.05) by Circuit\(_{HIIT}\), whereas Circuit\(_{combined}\) improved perception of general health more (p < 0.05). Both interventions lowered body mass, body-mass-index, waist-to-hip ratio, fat mass, and enhanced fat-free mass; decreased ratings of perceived exertion during submaximal treadmill running; improved the numbers of push-ups, burpees, one-legged squats, and 30-s skipping performed, as well as the height of counter-movement jumps; and improved physical and social functioning, role of physical limitations, vitality, role of emotional limitations, and mental health to a similar extent (all p < 0.05). Either forms of these multi-stimulating, circuit-like, multiple-joint training can be employed to improve body composition, selected variables of functional strength, and certain dimensions of quality of life in overweight women. However, Circuit\(_{HIIT}\) improves peak oxygen uptake to a greater extent, but with more perception of pain, whereas Circuit\(_{Combined}\) results in better perception of general health.},
  language  = {en}
}
@article{BornZinnerSperlich2017,
  author    = {Born, Dennis-Peter and Zinner, Christoph and Sperlich, Billy},
  title     = {The mucosal immune function is not compromised during a period of high-intensity interval training. Is it time to reconsider an old assumption?},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  number    = {485},
  doi       = {10.3389/fphys.2017.00485},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158025},
  year      = {2017},
  abstract  = {Purpose: The aim of the study was to evaluate the mucosal immune function and circadian variation of salivary cortisol, Immunoglobin-A (sIgA) secretion rate and mood during a period of high-intensity interval training (HIIT) compared to long-slow distance training (LSD). Methods: Recreational male runners (n = 28) completed nine sessions of either HIIT or LSD within 3 weeks. The HIIT involved 4 × 4 min of running at 90-95\% of maximum heart rate interspersed with 3 min of active recovery while the LSD comprised of continuous running at 70-75\% of maximum heart rate for 60-80 min. The psycho-immunological stress-response was investigated with a full daily profile of salivary cortisol and immunoglobin-A (sIgA) secretion rate along with the mood state on a baseline day, the first and last day of training and at follow-up 4 days after the last day of training. Before and after the training period, each athlete's running performance and peak oxygen uptake (V·O\(_{2peak}\)) was determined with an incremental exercise test. Results: The HIIT resulted in a longer time-to-exhaustion (P = 0.02) and increased V·O\(_{2peak}\) compared to LSD (P = 0.01). The circadian variation of sIgA secretion rate showed highest values in the morning immediately after waking up followed by a decrease throughout the day in both groups (P < 0.05). With HIIT, the wake-up response of sIgA secretion rate was higher on the last day of training (P < 0.01) as well as the area under the curve (AUC\(_{G}\)) higher on the first and last day of training and follow-up compared to the LSD (P = 0.01). Also the AUC\(_{G}\) for the sIgA secretion rate correlated with the increase in V·O\(_{2peak}\) and running performance. The AUC\(_{G}\) for cortisol remained unaffected on the first and last day of training but increased on the follow-up day with both, HIIT and LSD (P < 0.01). Conclusion: The increased sIgA secretion rate with the HIIT indicates no compromised mucosal immune function compared to LSD and shows the functional adaptation of the mucosal immune system in response to the increased stress and training load of nine sessions of HIIT.},
  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}
}
@article{SperlichBeckerHothoetal.2017,
  author    = {Sperlich, Billy and Becker, Martin and Hotho, Andreas and Wallmann-Sperlich, Birgit and Sareban, Mahdi and Winkert, Kay and Steinacker, J{\"u}rgen M. and Treff, Gunnar},
  title     = {Sedentary behavior among national elite rowers during off-training — a pilot study},
  series = {Frontiers in Physiology},
  volume    = {8},
  journal   = {Frontiers in Physiology},
  number    = {655},
  doi       = {10.3389/fphys.2017.00655},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158753},
  year      = {2017},
  abstract  = {The aim of this pilot study was to analyze the off-training physical activity (PA) profile in national elite German U23 rowers during 31 days of their preparation period. The hours spent in each PA category (i.e., sedentary: <1.5 metabolic equivalents (MET); light physical activity: 1.5-3 MET; moderate physical activity: 3-6 MET and vigorous intense physical activity: >6 MET) were calculated for every valid day (i.e., >480 min of wear time). The off-training PA during 21 weekdays and 10 weekend days of the final 11-week preparation period was assessed by the wrist-worn multisensory device Microsoft Band II (MSBII). A total of 11 rowers provided valid data (i.e., >480 min/day) for 11.6 week days and 4.8 weekend days during the 31 days observation period. The average sedentary time was 11.63 ± 1.25 h per day during the week and 12.49 ± 1.10 h per day on the weekend, with a tendency to be higher on the weekend compared to weekdays (p = 0.06; d = 0.73). The average time in light, moderate and vigorous PA during the weekdays was 1.27 ± 1.15, 0.76 ± 0.37, 0.51 ± 0.44 h per day, and 0.67 ± 0.43, 0.59 ± 0.37, 0.53 ± 0.32 h per weekend day. Light physical activity was higher during weekdays compared to the weekend (p = 0.04; d = 0.69). Based on our pilot study of 11 national elite rowers we conclude that rowers display a considerable sedentary off-training behavior of more than 11.5 h/day.},
  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{BornKunzSperlich2017,
  author    = {Born, Dennis-Peter and Kunz, Philipp and Sperlich, Billy},
  title     = {Reliability and validity of an agility-like incremental exercise test with multidirectional change-of-direction movements in response to a visual stimulus},
  series = {Physiological Reports},
  volume    = {5},
  journal   = {Physiological Reports},
  number    = {9},
  doi       = {10.14814/phy2.13275},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158265},
  pages     = {e13275},
  year      = {2017},
  abstract  = {The aim of the study was to evaluate the reliability and validity of cardiorespiratory and metabolic variables, that is, peak oxygen uptake (V'O\(_{2peak}\)) and heart rate (HR\(_{peak}\)), obtained from an agility-like incremental exercise test for team sport athletes. To investigate the test-retest reliability, 25 team sport athletes (age: 22 ± 3 years, body mass: 75 ± 7 kg, height: 182 ± 6 cm) performed an agility-like incremental exercise test on the SpeedCourt (SC) system incorporating multidirectional change-of-direction (COD) movements twice. For each step of the incremental SC test, the athletes covered a 40-m distance interspersed with a 10-sec rest period. Each 40 m distance was split into short sprints (2.25-6.36 m) separated by multidirectional COD movements (0°-180°), which were performed in response to an external visual stimulus. All performance and physiological data were validated with variables obtained from a ramp-like treadmill and Yo-Yo intermittent recovery level 2 test (Yo-Yo IR2). The incremental SC test revealed high test-retest reliability for the time to exhaustion (ICC = 0.85, typical error [TE] = 0.44, and CV\% = 3.88), V'O\(_{2peak}\), HR\(_{peak}\), ventilation, and breathing frequency (ICC = 0.84, 0.72, 0.89, 0.77, respectively). The time to exhaustion (r = 0.50, 0.74) of the incremental SC test as well as the peak values for V'O\(_{2}\) (r = 0.59, 0.52), HR (r = 0.75, 0.78), ventilation (r = 0.57, 0.57), and breathing frequency (r = 0.68, 0.68) were significantly correlated (P ≤ 0.01) with the ramp-like treadmill test and the Yo-Yo IR2, respectively. The incremental SC test represents a reliable and valid method to assess peak values for V'O\(_{2}\) and HR with respect to the specific demand of team sport match play by incorporating multidirectional COD movements, decision making, and cognitive components.},
  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}
}