• A 15-year follow-up study of hip bone mineral density and associations with leisure time physical activity. The Tromsø Study 2001-2016 

      Mikkilä, Saija; Johansson, Jonas; Nordström, Anna Hava; Nordström, Peter; Emaus, Nina; Handegård, Bjørn Helge; Morseth, Bente; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-26)
      Aims<p> The aim was to investigate the long-term association between leisure time physical activity and hip areal bone mineral density (aBMD), in addition to change in hip aBMD over time, in 32–86 years old women and men.<p> <p>Methods <p>Data were retrieved from the 2001, 2007–2008, and 2015–2016 surveys of the Tromsø Study, a longitudinal population study in Norway. Leisure time physical ...
    • A 15-year follow-up study of hip bone mineral density and associations with leisure time physical activity. The Tromsø Study 2001-2016 

      Mikkilä, Saija; Johansson, Jonas; Nordström, Anna Hava; Nordström, Peter; Emaus, Nina; Handegård, Bjørn Helge; Morseth, Bente; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-26)
      Aims<p> <p>The aim was to investigate the long-term association between leisure time physical activity and hip areal bone mineral density (aBMD), in addition to change in hip aBMD over time, in 32–86 years old women and men.<p> <p>Methods <p>Data were retrieved from the 2001, 2007–2008, and 2015–2016 surveys of the Tromsø Study, a longitudinal population study in Norway. Leisure time physical activity ...
    • 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 ...
    • Acute Post-Exercise Blood Pressure Responses in Middle-Aged Persons with Elevated Blood Pressure/Stage 1 Hypertension following Moderate and High-Intensity Isoenergetic Endurance Exercise 

      Gjøvaag, Terje; Berge, Hanna; Olsrud, Marianne; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2020)
      This study investigated the acute post-exercise hypotension (PEH) response in persons with elevated blood pressure or stage 1 hypertension following moderate and high-intensity isoenergetic endurance exercise. Twelve middle-aged persons (six females), with resting systolic and diastolic BP of 130±6 and 84±7 mmHg, participated in three bicycle ergometer bouts: 1) Testing of peak aerobic capacity ...
    • Annual Volume and Distribution of Physical Training in Norwegian Female Cross-Country Skiers and Biathletes: A Comparison Between Sports, Competition Levels, and Age Categories — The Female Endurance Athlete Project 

      Osborne, John Owen; Solli, Guro Strøm; Engseth, Tina Pettersen; Welde, Boye; Morseth, Bente; Noordhof, Dionne Adriana; Sandbakk, Øyvind Bucher; Andersson, Bror Erik Petrus (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-11)
      Purpose To describe and compare the annual physical training characteristics between Norwegian female cross-country (XC) skiers and biathletes across competition levels and age categories. Methods Daily training sessions for one year were recorded for 45 XC skiers and 26 biathletes, comprising international/national-team [inter(national)] and non-national/regional-team members (non-national) ...
    • Associations between maximal strength, sprint, and jump height and match physical performance in high‐level female football players 

      Pedersen, Sigurd; Welde, Boye; Sagelv, Edvard Hamnvik; Heitmann, Kim Arne; Randers, Morten B.; Johansen, Dag; Pettersen, Svein Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-06)
      Studies on females’ decisive physical components to physical match-play performance are sparse and only emphasize endurance tests. Thus, the influence of maximal strength and power on physical performance during match-play is currently unknown. The aim of this study was to assess the association between one repetition maximum (1RM) half squat strength, 5-, 10-, and 15-m sprint times, countermovement ...
    • Biomechanical differences in double poling between sexes and level of performance during a classical cross-country skiing competition 

      Jonsson, Malin; Welde, Boye; Stoggl, Thomas Leonhard (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-12)
      Biomechanical differences in double poling (DP) between sex and performance level were investigated in female and male cross-country skiers during a classical race (10/15 km). Skiers were divided into faster and slower on basis of race performance: females faster (n=20), females slower (n=20), males faster (n=20), and males slower (n=20). Based on video analysis while DP in a flat section of the ...
    • 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 ...
    • Cross-sectional associations between accelerometer-measured physical activity and hip bone mineral density. The Tromsø study 2015–2016 

      Mikkilä, Saija; Handegård, Bjørn Helge; Johansson, Jonas Lars; Hopstock, Laila Arnesdatter; van den Tillaar, Roland Johannes Wilhelmus; Emaus, Nina Alice; Morseth, Bente; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-06)
      Positive associations between physical activity and bone health have been found in population-based studies, however, mostly based on self-reported physical activity. Therefore, we investigated the association between accelerometer-measured physical activity, measured in steps per day and minutes of moderate to vigorous physical activity (MVPA) per day, and total hip areal bone mineral density (aBMD) ...
    • Cross-sectional associations between accelerometry-measured physical activity, left atrial size, and indices of left ventricular diastolic dysfunction: The Tromsø Study 

      Heitmann, Kim Arne; Løchen, Maja-Lisa; Hopstock, Laila Arnesdatter; Stylidis, Michael; Welde, Boye; Schirmer, Henrik; Morseth, Bente (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-31)
      Whereas left atrial (LA) enlargement is an independent predictor for adverse cardiovascular events and all-cause mortality, this is regarded a physiological adaption of exercise. Paradoxically, LA size in athletes may overlap the enlargement observed in patients with cardiac pathology. Current knowledge is mainly derived from studies of athletes, and little is known about cardiac adaptations to ...
    • Editorial: The physiology of the female athlete—performance, health, and recovery 

      Welde, Boye; Kellawan, J. Mikhail; Larson, Rebecca D.; Morseth, Bente; Osborne, John Owen; Sandbakk, Øyvind Bucher (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-31)
      Females are historically underrepresented in sports science research, with relatively few studies investigating female physiology in relation to exercise and sports performance, health, and recovery. This knowledge gap also extends to training planning, periodization, and peaking, where previous research has predominantly focused on male participants. Consequently, female athletes and their ...
    • Effect of Computational Method on Accumulated O2 Deficit 

      Medbø, Jon Ingulf; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-07)
      The aim of this study was to examine how relationships between exercise intensity and the rate of energy release established in different ways, affect the calculated O<sub>2</sub> deficit accumulated during strenuous exercise. Aerobic energy release is readily measured by the O<sub>2</sub> uptake, while anaerobic energy release is by definition independent of O<sub>2</sub>. The latter is not ...
    • The effect of pole length on physiological and perceptual responses during G3 roller ski skating on uphill terrain 

      Torvik, Per Øyvind; Heimburg, Erna Dianne von; Sende, Torkel; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-22)
      The benefits of using longer than self-selected poles have been shown in double poling, but these potential benefits have not been examined in the gear 3 ski skating sub-technique (G3), during which the poling movement is very similar to double poling. The aim of this study was to examine the effect of longer than self-selected poles on physiological and perceptual responses in the G3 sub-technique. ...
    • Effect of Sex, Body Mass Index and Physical Activity Level on Peak Oxygen Uptake Among 14–19 Years Old Adolescents 

      Welde, Boye; Morseth, Bente; Handegård, Bjørn Helge; Lagestad, Pål Arild (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-30)
      The aim was to describe longitudinal trends in peak oxygen uptake (VO<sub>2peak</sub>) among 14- to 19-year-old adolescents in Norway, and to examine effects of sex, body mass index (BMI), and physical activity (PA) level on VO<sub>2peak</sub> during adolescence. Of 124 invited students from two lower secondary schools in Norway, 116 eighth-grade students (61 boys and 55 girls; 14 years old at ...
    • Effects of Linear Versus Changes of Direction Repeated Sprints on Intermittent High Intensity Running Performance in High-level Junior Football Players over an Entire Season: A Randomized Trial 

      Sagelv, Edvard Hamnvik; Selnæs, Ivar; Pedersen, Sigurd; Pettersen, Svein Arne; Randers, Morten B.; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-06)
      <i>Abstract</i>: Background: Changes of direction (COD) repeated sprints (RSs) might have greater relevance to football than linear RSs. We aimed to compare the effects of linear and COD RSs on intermittent high intensity running (HIR) over an entire season. <p> <p><i>Methods</i>: In total, 19 high-level male football players (16–19 years) randomly performed linear RSs or COD RSs twice a week ...
    • Effects of Linear Versus Changes of Direction Repeated Sprints on Intermittent High Intensity Running Performance in High-level Junior Football Players over an Entire Season: A Randomized Trial 

      Sagelv, Edvard H.; Selnæs, Ivar; Pedersen, Sigurd; Pettersen, Svein Arne; Randers, Morten B.; Welde, Boye (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-06)
      <i>Background</i>: Changes of direction (COD) repeated sprints (RSs) might have greater relevance to football than linear RSs. We aimed to compare the effects of linear and COD RSs on intermittent high intensity running (HIR) over an entire season. <p> <p><i>Methods</i>: In total, 19 high-level male football players (16–19 years) randomly performed linear RSs or COD RSs twice a week during their ...
    • 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>, ...
    • Flywheel squats versus free weight high load squats for improving high velocity movements in football. A randomized controlled trial 

      Sagelv, Edvard Hamnvik; Pedersen, Sigurd; Nilsen, Lars Petter R.; Casolo, Andrea; Welde, Boye; Randers, Morten B.; Pettersen, Svein Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-02)
      <i>Background</i> - High load (HL: > 85% of one repetition maximum (1RM)) squats with maximal intended velocity contractions (MIVC) combined with football sessions can be considered a relevant and time-efficient practice for maintaining and improving high velocity movements in football. Flywheel (FW) resistance exercise (RE) have recently emerged with promising results on physical parameters associated ...
    • Hormonal Contraceptive Use and Self-Reported Menstrual Cycle-Related Symptom Frequency and Severity in Norwegian Team Handball Players of Different Competition Levels 

      Osborne, John Owen; Andersson, Erik P.; Pedersen, Sigurd; Welde, Boye; Emaus, Aina; Solli, Guro Strøm; Gunnarshaug, Tora Vilje D.; Engseth, Tina Pettersen (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-14)
      Purpose: To compare the frequency and severity of self-perceived negative symptoms associated with the menstrual cycle or hormonal-contraceptive (HC) cycle between (1) HC users and non–HC users and (2) different competition levels. An additional aim was to describe the rate and type of HC use and prevalence of potential menstrual-cycle disturbances in female team handball players. <p> <p>Methods: ...
    • 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 ...