• Effects of upper-body sprint-interval training on strength and endurance capacities in female cross-country skiers 

      Vandbakk, Kristine; Welde, Boye; Hovstein, Andrea; Baumgart, Julia Kathrin; Ettema, Gertjan; Karlsen, Trine; Sandbakk, Øyvind (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-27)
      Thermal conductivity and thermal diffusivity of ionic liquids (ILs) are investigated in this work. A hot disk method for ILs thermal conductivity and thermal diffusivity measurement is utilized. Firstly, the thermal conductivity of water is measured to check the reliability of the hot disk method. In addition, the thermal conductivity of pure ILs, including BmimBF<sub>4</sub>, BmimPF<sub>6</sub>, ...
    • Functional High-Intensity Circuit Training Improves Body Composition, Peak Oxygen Uptake, Strength, and Alters Certain Dimensions of Quality of Life in Overweight Women 

      Sperlich, Billy; Wallmann-Sperlich, Birgit; Zinner, Christoph; Von Stauffenberg, Valerie; Losert, Heidrun; Holmberg, Hans-Christer (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-03)
      The effects of circuit-like functional high-intensity training (Circuit<sub>HIIT</sub>) alone or in combination with high-volume low-intensity exercise (Circuit<sub>combined</sub>) 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, ...
    • Instant Biofeedback Provided by Wearable Sensor Technology Can Help to Optimize Exercise and Prevent Injury and Overuse 

      Düking, Peter; Holmberg, Hans-Christer; Sperlich, Billy (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-03)
      With great interest, we have been following the developing variety and popularity of commercially available wearable sensor technologies, as well as the discussion concerning their usefulness for improving fitness and health (Duking et al., 2016; Halson et al., 2016; Sperlich and Holmberg,2016). Although many of these devices may not necessarily fulfill scientific criteria for quality (Sperlich and ...
    • Chronotype, Physical Activity, and Sport Performance: A Systematic Review 

      Vitale, Jacopo Antonino; Weydahl, Andi (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-11)
      Background:<br> Many variables related to sport have been shown to have circadian rhythms. Chronotype is the expression of circadian rhythmicity in an individual, and three categories of chronotype are defined: morning types (M-types), evening types (E-types), and neither types (N-types). M-types show earlier peaks of several psychophysiological variables during the day than E-types. The effect ...
    • Chronotype and response to training during the polar night: a pilot study 

      Vitale, Jacopo Antonino; Bjørkesett, Eva; Campana, Andrea; Panizza, Giacomo; Weydahl, Andi (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-19)
      Background:<br> An individual’s chronotype influences his or her physiological rhythms. Some studies have looked at the effect of time of day on the responses to exercise, but studies on the effect of long-term training are lacking. <br>Objective:<br> To report the effects of an 8-week training period during the polar night in non- athletes of different chronotypes living at 70°N. <br>Design:<br> ...
    • Accelerations and high intensity running in field and assistant football referees during match play 

      Riiser, Amund; Pettersen, Svein Arne; Andersen, Vidar; Sæterbakken, Atle Hole; Frøyd, Christian; Ylvisåker, Einar; Moe, Vegard Fusche (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-20)
      <p><i>Objectives</i>: (1) to examine accelerations and high intensity running (HIR) in football field referees (FR) and assistant referees (AR) during football matches and (2) to evaluate fluctuations in accelerations and HIR between first and second half and in 5-min periods.</p> <p><i>Methods</i>: All movements of the referees were measured using a radio-based tracking system during 41 matches ...
    • The Responses of Elite Athletes to Exercise: An All-Day, 24-h Integrative View Is Required! 

      Sperlich, Billy; Holmberg, Hans-Christer (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-14)
      The current research topics in Frontiers of Physiology include “Training intensity, volume and recovery distribution among elite and recreational endura nce athletes” (Frontiers in Physiology, 2016) and “Wearable Sensor Technology for Monitoring Training Load and Health in the Athletic Population” (Frontiers in Physiology, 2017). As editors of both of these topics, we would like to share some ...
    • A SWOT Analysis of the Use and Potential Misuse of Implantable Monitoring Devices by Athletes 

      Sperlich, Billy; Düking, Peter; Holmberg, Hans-Christer (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-05)
      We have been following the developments and popularity of commercially available wearable sensor technology, as well as the ongoing discussion concerning its usefulness for improving the fitness and health of athletes (Düking et al., 2016, 2017; Sperlich and Holmberg, 2017) with considerable interest. Here, we would like to draw attention to a new generation of implantable devices (implantables) ...
    • Learning leadership: becoming an outdoor leader 

      Enoksen, Elisabeth; Lynch, Pip (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-19)
      Recent leadership research has demonstrated a need for better understanding the process of becoming a leader because it might be qualitatively different to being a leader. If so, there is likely to be a need for pedagogies designed deliberately to support first-time outdoor leadership experiences and any such pedagogies must be informed by the needs of first-time leaders. Becoming a leader in outdoor ...
    • Health challenges in long-distance dog sled racing: A systematic review of literature 

      Calogiuri, Giovanna; Weydahl, Andi (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)
      Long-distance dog sled races, e.g. Iditarod (Alaska) and Finnmarksløpet (Northern Norway), are extremely demanding sporting events that might expose mushers, handlers and a large number of organisers and volunteers to risks for their health. The purpose of this systematic literature review (PROSPERO registration n. CRD42017069136) was to identify and summarise all available scientific literature ...
    • Absentee rates in physical education in high schools: The importance of gender and study programmes 

      Lagestad, Pål Arild; Welde, Boye; Rånes, Vebjørn; Myhre, Hege (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)
      Little is known about absenteeism in high school physical education (PE) in relation to study programme and gender. This study investigated the impact of gender and study programme on absentee rates in PE by analyzing data, using non-parametric statistical analyses, from the absentee registers for all 6928 students in Nordland Country. The results showed that the absentee rates in PE differed among ...
    • The pacing strategy and technique of male cross-country skiers With different levels of performance during a 15-km classical race 

      Welde, Boye; Stöggl, Thomas; Mathisen, Gunnar; Supej, Matej; Zoppirolli, Chiara; Winther, Andreas Kjæreng; Pellegrini, Barbara; Holmberg, Hans-Christer (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-08)
      In this study the pacing strategy, cycle characteristics and choice of technique of elite male cross-country (XC) skiers during a three-lap, 15-km classical race with interval start were measured. During the Norwegian Championships in 2016, fast (n = 18, age: 26±4 yr; height: 182±4 cm; body mass: 78±3 kg (means±SD)) and slow skiers (n = 18, age: 22±2 yr; height: 183±5 cm; body mass: 78±6 kg) were ...
    • Comparison of Long and Short High-Intensity Interval Exercise Bouts on Running Performance, Physiological and Perceptual Responses 

      Valstad, Sverre; Heimburg, Erna von; Welde, Boye; van den Tillaar, Roland (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-18)
      This study compared the effects of long (4×4 min) and short intervals (4×8×20 s) of high-intensity interval exercise bouts (HIIT) on running performance, physiological and perceptual responses, and excess postexercise oxygen consumption (EPOC). Twelve healthy college students (8 men, 4 women; mean age=22±2 years) performed long (90–95% of peak heart rate) and short intervals (maximal intensity) of ...
    • The ambiguity of physical activity, exercise and atrial fibrillation 

      Morseth, Bente; Løchen, Maja-Lisa; Ariansen, Inger Kristine Holtermann; Myrstad, Marius; Thelle, Dag Steinar (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-07)
      Although commonly associated with cardiovascular disease or other medical conditions, atrial fibrillation may also occur in individuals without any known underlying conditions. This manifestation of atrial fibrillation has been linked to extensive and long-term exercise, as prolonged endurance exercise has shown to increase prevalence and risk of atrial fibrillation. In contrast, more modest physical ...
    • Impact of incline, sex and level of performance on kinematics during a distance race in classical cross-country skiing 

      Stöggl, Thomas; Welde, Boye; Supej, Matej; Zoppirolli, Chiarra; Rolland, Carsten Gade; Holmberg, Hans-Christer; Pellegrini, Barbara (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-01)
      Here, female and male elite cross-country (XC) skiers were compared on varying terrain during an official 10-km (women) and 15-km (men) Norwegian championship race. On the basis of race performance, 82 skiers were classified as fast (FS) (20 women, 20 men) or slower (SS) (21, 21) skiers. All were video recorded on flat (0°), intermediate (3.5°), uphill (7.1°) and steep uphill (11°) terrain during ...
    • The Potential Usefulness of Virtual Reality Systems for Athletes: A Short SWOT Analysis 

      Düking, Peter; Holmberg, Hans-Christer; Sperlich, Billy (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-05)
      Virtual reality (VR) systems (Neumann et al., 2017), which are currently receiving considerable attention from athletes, create a two- or three-dimensional environment in the form of emulated pictures and/or video-recordings where in addition to being mentally present, the athlete even often feels like he/she is there physically as well. As she/he interacts with and/or reacts to this environment, ...
    • Whole-body vibrations associated with alpine skiing: A risk factor for low back pain? 

      Supej, Matej; Ogrin, Jan; Holmberg, Hans-Christer (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-09)
      Alpine skiing, both recreational and competitive, is associated with high rates of injury. Numerous studies have shown that occupational exposure to whole-body vibrations is strongly related to lower back pain and some suggest that, in particular, vibrations of lower frequencies could lead to overuse injuries of the back in connection with alpine ski racing. However, it is not yet known which ...
    • Recommendations for assessment of the reliability, sensitivity, and validity of data provided by wearable sensors designed for monitoring physical activity 

      Düking, Peter; Fuss, Franz Konstantin; Holmberg, Hans-Christer; Sperlich, Billy (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-30)
      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, ...
    • 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 

      Sperlich, Billy; Hahn, Lea-Sofie; Edel, Antonia; Behr, Tino; Helmprobst, Julian; Leppich, Robert; Wallmann-Sperlich, Birgit; Holmberg, Hans-Christer (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-09)
      The present study was designed to assess the psycho-physiological responses of physically untrained individuals to mobile-based multi-stimulating, circuit-like, multiplejoint conditioning (Circuit<sub>HIIT</sub>) performed either once (1xCircuit<sub>HIIT</sub>) or twice (2xCircuit<sub>HIIT</sub>) daily for 4 weeks. In this single-center, two-arm randomized, controlled study, 24 men and women (age: ...
    • Macro-kinematic differences between Sprint and Distance cross-country skiing competitions using the classical technique 

      Marsland, Finn; Anson, Judith; Waddington, Gordon; Holmberg, Hans-Christer; Chapman, Dale W (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-17)
      We compare the macro-kinematics of six elite female cross-country skiers competing in 1.1-km Sprint and 10.5-km Distance classical technique events on consecutive days under similar weather and track conditions. The relative use of double pole (DP), kick-double pole (KDP), diagonal stride (DS), tucking (Tuck) and turning (Turn) subtechniques, plus each technique’s respective velocities, cycle ...