Physiological Profile of Male Competitive and Recreational Surfers

Surfing consists of both high- and low-intensity paddling of varying durations, using both the aerobic and anaerobic systems. Surf-specific physiological studies lack adequate group sample sizes, and V[Combining Dot Above]O2peak values are yet to determine the differences between competitive and recreational surfers. The purpose of this study was therefore to provide a comprehensive physiological profile of both recreational and competitive surfers. This multisite study involved 62 male surfers, recreational (n = 47) and competitive (n = 15). Anthropometric measurements were conducted followed by dual-energy x-ray absorptiometry, anaerobic testing and finally aerobic testing. V[Combining Dot Above]O2peak was significantly greater in competitive surfers than in recreational surfers (M = 40.71 ± 3.28 vs. 31.25 ± 6.31 ml·kg·min, p \u3c 0.001). This was also paralleled for anaerobic power (M = 303.93 vs. 264.58 W) for competitive surfers. Arm span and lean total muscle mass was significantly (p ≤ 0.01) correlated with key performance variables (V[Combining Dot Above]O2peak and anaerobic power). No significant (p ≥ 0.05) correlations were revealed between season rank and each of the variables of interest (V[Combining Dot Above]O2peak and anaerobic power). Key performance variables (V[Combining Dot Above]O2peak and anaerobic power) are significantly higher in competitive surfers, indicating that this is both an adaptation and requirement in this cohort. This battery of physiological tests could be used as a screening tool to identify an athlete\u27s weaknesses or strengths. Coaches and clinicians could then select appropriate training regimes to address weaknesses

The role of motion analysis in elite soccer

The optimal physical preparation of elite soccer (association football) players has become an indispensable part of the professional game especially due to the increased physical demands of match-play. The monitoring of players’ work-rate profiles during competition is now feasible through computer-aided motion analysis. Traditional methods of motion analysis were extremely labour intensive and were largely restricted to university- based research projects. Recent technological developments have meant that sophisticated systems, capable of quickly recording and processing the data of all players’ physical contributions throughout an entire match, are now being used in elite club environments. In recognition of the important role motion analysis now plays as a tool for measuring the physical performance of soccer players, this review critically appraises various motion analysis methods currently employed in elite soccer and explores research conducted using these methods. This review therefore aims to increase the awareness of both practitioners and researchers of the various motion analysis systems available, identify practical implications of the established body of knowledge, while highlighting areas that require further exploration

Durability of Vacuum Insulation Panels in Alkaline Environment

Concrete and lightweight concrete elements are today used in various building applications to a great extent all over the world. Replacing traditional thermal insulation like e.g. expanded polystyrene (EPS), extruded polystyrene (XPS) and polyurethane (PUR) by vacuum insulation panels (VIPs) is discussed in order to increase the thermal resistance without increasing the wall thickness. Compared to traditional concrete and lightweight concrete elements, slimmer elements may still achieve U-values low enough to fulfil passive house or zero energy requirements. Thus, sandwich elements with VIPs may be an alternative to the traditional solutions. However, there may be some problems related to the use of VIPs in such concrete elements. The alkaline environment in concrete may lead to reactions with the aluminium (Al) in the multi-layered laminate used as the VIP envelope, and destroy its barrier function. To investigate the influence of the alkaline environment on the durability of VIPs in general, and the VIP envelope in particular, various VIP and VIP envelope specimen experiments have been carried out. The VIPs were subjected to different alkaline solutions at different temperatures, with and without direct contact with the liquid alkaline solutions. A worst-case scenario was investigated when any additional protection of the VIPs was disregarded. The results from the VIP experiments showed various degrees of degradation effects. Depending on the temperature and the pH-value of the alkaline environment the VIPs were exposed to, physical and thermal changes were observed on some of the test specimens, while others were more or less unaffected by the exposure. In general, the temperature proved to be the hardest strain, when the VIPs in heating cabinet showed much greater signs of degradation than the VIPs at room temperature, more or less independent on the pH-value of the alkaline solution they were exposed to. Interesting results were also obtained from the VIP envelope specimen experiment, where the VIP envelope showed signs of degradation after only a short time in alkaline solution

Mechanisms of exercise-induced improvements in the contractile apparatus of the mammalian myocardium

One of the main outcomes of aerobic endurance exercise training is the improved maximal oxygen uptake, and this is pivotal to the improved work capacity that follows the exercise training. Improved maximal oxygen uptake in turn is at least partly achieved because exercise training increases the ability of the myocardium to produce a greater cardiac output. In healthy subjects, this has been demonstrated repeatedly over many decades. It has recently emerged that this scenario may also be true under conditions of an initial myocardial dysfunction. For instance, myocardial improvements may still be observed after exercise training in post-myocardial infarction heart failure. In both health and disease, it is the changes that occur in the individual cardiomyocytes with respect to their ability to contract that by and large drive the exercise training-induced adaptation to the heart. Here, we review the evidence and the mechanisms by which exercise training induces beneficial changes in the mammalian myocardium, as obtained by means of experimental and clinical studies, and argue that these changes ultimately alter the function of the whole heart and contribute to the changes in whole-body function

Application of the speed-duration relationship to normalize the intensity of high-intensity interval training

The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM) relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT) has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8) then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4), 6 min (WR6) and 8 min (WR8), interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT) on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min). A sub-group of subjects (n = 6) also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT) to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (P<0.050). For maximal HIIT, there was no difference in tLIM of each of the 4 bouts (Bout 1: 229±27 s; Bout 2: 262±37 s; Bout 3: 235±49 s; Bout 4: 235±53 s; P>0.050). However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m), 3 (136.9±38.9 m), and 4 (136.7±39.3 m), compared with bout 1 (264.9±58.7 m; P>0.050). These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols

The efficacy of unsupervised home-based exercise regimens in comparison to supervised lab-based exercise training upon cardio-respiratory health facets

Supervised high-intensity interval training (HIIT) can rapidly improve cardiorespiratory fitness (CRF). However, the effectiveness of time-efficient unsupervised home-based interventions is unknown. Eighteen volunteers completed either: laboratory-HIIT (L HIIT); home-HIIT (H-HIIT) or home-isometric hand-grip training (H-IHGT). CRF improved significantly in L-HIIT and H-HIIT groups, with blood pressure improvements in the H-IHGT group only. H-HIIT offers a practical, time-efficient exercise mode to improve CRF, away from the laboratory environment. H-IHGT potentially provides a viable alternative to modify blood pressure in those unable to participate in whole-body exercise

High intensity interval training in handcycling: The effects of a 7 week training intervention in able-bodied men

Introduction: In lower body endurance training, quantities of both moderate intensity continuous training (MICT) and high intensity interval training (HIIT) can lead to an improved physiological capacity and performance. Limited research is available regarding the endurance and muscular capacity of the upper body, and how training contributes to improvements in performance capacity is still unknown. The aim of the current study was to evaluate the effects of HIIT and MICT on the physiological capacity and handcycling performance of able-bodied men in a well-controlled laboratory setting. Methods: Twenty four recreationally active men (22 ± 2 years; 1.84 ± 0.04 m; 79 ± 10 kg) were matched on incremental handcycling pre-test performance (peakPO) and then randomly assigned to HIIT, MICT, or a non-training control group (CON, 3 × n = 8). Participants in HIIT completed 14 interval training sessions, performing 4 × 4 min intervals at 85% heart rate reserve (%HRR), and seven continuous training sessions at 55 %HRR (every 2nd training session of the week). Participants in MICT performed 21 training sessions of 30 min at 55 %HRR. After the intervention, changes in peak oxygen uptake (peakVO2) and peak power output (peakPO) were compared within and between HIIT, MICT and CON. Results: The average external training load per training session did not differ between MICT and HIIT (p = 0.713). Improvements after HIIT in peakVO2 (22.2 ± 8.1%) and peakPO (47.1 ± 20.7%) were significantly larger compared with MICT and CON (p < 0.001). Improvements after MICT in peakVO2 (10.7 ± 12.9%) and peakPO (32.2 ± 8.1%) were higher compared to CON (p < 0.001). Higher improvement after HIIT occurred despite training 22% less time than MICT. No significant changes were found in CON. Discussion: As in lower body endurance sports, HIIT proved to be very effective in improving the physiological and performance capacity of upper body exercise. Whilst physiological capacity in both training groups improved significantly compared with CON, the present study shows that peakVO2 and peakPO improved more after HIIT than after MICT in able-bodied men. It is advised to include HIIT into training regimes of recreational and competitive handcyclists to improve the upper body endurance capacity

Changes in anthropometry and performance, and their inter-relationships, across three seasons in elite youth rugby league players

This is a non-final version of an article published in final form in Journal of Strength and Conditioning Research, 2014, 28(11), pp. 3128-3136.This study investigated changes in anthropometry and performance, and their inter-relationships, across three consecutive seasons (under-15 to under-17 age group) in elite youth rugby league players. Each player took part in annual anthropometrical and performance assessments, comprising measurements of stature; body mass; limb lengths and circumference; skinfolds, predicted muscle cross-sectional area (CSA); 20 m speed, counter-movement jump height, vertical power and aerobic power. Lean body mass % changed (P < 0.05) between the under-15 (70.9 ± 5.9 %), under-16 (72.0 ± 5.8 %) and the under-17 age groups (74.1 ± 5.7 %). Likewise, predicted quadriceps muscle cross-sectional area (CSA) also changed (P < 0.05) between each age group (under-15 = 120.9 ± 37.8 cm2; under-16 = 133.2 ± 36.0 cm2; under-17 = 154.8 ± 28.3 cm2). Concomitant changes between the under-15 and under-16 group were found for 20 m speed (3.5 ± 0.1 cf. 3.4 ± 0.2 s; P = 0.008) and predicted jumping power (3611.3 ± 327.3 W cf. 4081.5 ± 453.9 W; P = 0.003). Both lean body mass and quadriceps muscle CSA consistently, related to both 20 m sprint time and jumping power, with r-values ranging between -0.39 to –0.63 (20 m sprint time) and 0.55 to 0.75 (jumping power). Our findings demonstrate the importance of gains in lean body mass across later-adolescence that support the ability to generate horizontal speed and predicted vertical power. This information should inform the expectations and subsequent training programs of elite rugby league practitioners

Radikalisering av etnisk vesteuropeiske konvertitter til islam post 11. september 2001. En komparativ studie av mulige årsaksmekanismer med strategiske implikasjoner for antiradikaliseringsarbeidet

Denne oppgaven tar utgangspunkt i en hypotese om at marginalisering og traumatiske livshendelser på et personlig plan, og påfølgende opprørstrang, går forut for og frembringer radikalisering av etnisk vesteuropeiske konvertitter til islam etter årtusenskiftet. Hypotesen er fremtredende i forskningsfronten, men samtidig i liten grad testet. Hypotesen får bare delvis støtte. Bekjentskaper, samt interaksjon med islamistiske ideologer og nettverk, ser gjennomgående ut til å ha større betydning for radikaliseringen enn trekk ved studerte enheter selv eller deres livssituasjon. Tross feilkildene som hefter ved valgte forskningsdesign, er funnene såpass robuste at de gir grunnlag for en nyansering av bildet visse teoretikere tegner av radikaliserte, etnisk vesteuropeiske konvertitter til islam som marginaliserte og opprørske tapere . Tilsvarende er det belegg for justeringer av relevante antiradikaliseringstiltak. Det er også formulert en hypotese om at elementer i global islamistisk ideologi inngår i radikaliserte, etnisk vesteuropeiske konvertitters motivasjon for troverdige trusler om, planlagte eller faktisk gjennomførte terrorangrep mot vestlige mål etter årtusenskiftet. Hypotesen får støtte. Et hovedpoeng i oppgaven er at vesteuropeiske stater ikke vil lykkes med å håndtere trusselen fra globalt orienterte militante islamister, herunder radikaliserte, etnisk vesteuropeiske konvertitter til islam, med mindre statene utarbeider en motstrategi som tar høyde for tankesettet og strategien bak global jihad. Med utgangspunkt i islamistisk originallitteratur skisseres seks overordnede prinsipper for antiradikaliseringsdelen av vesteuropeiske staters motstrategi. Det argumenteres spesielt for at antiradikaliseringsarbeidet må adressere det faktum at spredning av islamistisk ideologi, såkalt dawa, er et bærende og selvstendig element i globalt orienterte militante islamisters strategi

Barn 5-6 års oppfatning av skjermtid og bruk av digitale teknologier

Problemstilling: Hvordan oppfatter barn 5-6 år sin egen skjermtid og bruk av digitale teknologier, og hva påvirker deres syn på dette? Bakgrunn: Med en stadig økning i bruk av digitale teknologier og skjermtid blant barn er dette temaet aktuelt i dagens samfunn. I mai 2022 kom helsedirektoratet med nye anbefalinger for skjermtid for barn som skiller på aktiv og passiv skjermtid. Tidligere forskning omfatter mange studier på barn med foreldre og andre omsorgspersoner som informanter, men få har brukt barna selv som informanter. Hensikt: Å få innsikt i barnas synspunkter, oppfattelser og opplevelser av sin skjermtid og bruk av digitale teknologier, og hva som påvirker deres syn på det. Teoretisk rammeverk: Studiens teoretiske rammeverk tar utgangspunkt i aktør-nettverksteori, da dette er en teori som fokuserer like mye på interaksjon mellom materielle aktører som menneskelige. Metode: Studien har et kvalitativt forskningsdesign. Datainnsamlingen ble gjennomført av forskere fra den norske prosjektgruppen for DigiGen. Data ble samlet ved bruk av semistrukturerte intervjuer med barn både i grupper og individuelt. Resultat: Studien viser at nettbrett er den mest utbredte teknologien blant barna, og de bruker digitale teknologier mest til spilling og å se på programmer. Gjennom funnene i studien kan vi se at barna uttrykker at de har et ønske om økt bruk av skjerm, og at de har veldig varierte regler som begrenser bruken i større eller mindre grad. De oppfatter det som positivt med spilling, men noen vil helst leke med andre ting enn skjerm sammen med venner. Noen av barna oppfatter spilling og bruk av digitale teknologier som avslappende alenetid, mens andre ser det som sosialt. Videre viser studien at foreldrene har en sterk forhandlingsposisjon og er en sterk påvirker rundt barns bruk av digitale teknologier og skjerm. Resultatene peker også på at skjermen i seg selv er en sterk forhandlingskraft som påvirker barna. Reglene er også med på å påvirke barnas syn på egen bruk av digitale teknologier og skjermtid.publishedVersio