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Per Martin Arvidsson, Johannes Töger, Marcus Carlsson, Katarina Steding-Ehrenborg, Gianni Pedrizzetti, Einar Heiberg, Hakan Arheden
Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only LV forces. Right ventricular forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify three-dimensional hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. 25 controls,14 elite endurance athletes, and two patients with left ventricular dyssynchrony were included...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Mair Underwood
BACKGROUND: As a result of the mainstreaming of bodybuilding, the majority of image and performance enhancing drug (IPED) users are now not athletes or competitive bodybuilders, but recreational bodybuilders. Previous approaches provide little insight into how the shift from competitive to recreational contexts impacts the use of IPEDs. METHODS: In this study an online ethnographic approach is used to explore the social lives of IPEDs in a recreational context. The study focusses on the Zyzz fandom, an international online community of thousands of recreational bodybuilders who idolise the alleged IPED user Zyzz...
October 18, 2016: International Journal on Drug Policy
Aaron Manzanares, Ruperto Menayo, Francisco Segado
In a sport conditioned by natural elements such as sailing, visual perception is a key factor for the performance. The research has shown that the visual behaviour of athletes at different skill levels varies, which may cause differences in the performance achieved. The aim of this research was to examine the visual behaviour of sailors from different ranking positions at the start of a race in a simulated situation. Twenty junior sailors (N=10 top and N=10 bottom ranking) participated in the study. The visual behaviour was recorded at the start of a sailing simulation...
October 21, 2016: Motor Control
David Geard, Peter Reaburn, Amanda Rebar, Rylee Dionigi
Global population aging has raised academic interest in successful aging to a public policy priority. Currently there is no consensus regarding the definition of successful aging. However, a synthesis of research shows successful aging can be defined as a late-life process of change characterized by high physical, psychological, cognitive, and social functioning. Masters athletes systematically train for, and compete in, organized forms of team and individual sport specifically designed for older adults. Masters athletes are often proposed as exemplars of successful aging...
October 21, 2016: Journal of Aging and Physical Activity
David Herzig, Moreno Testorelli, Daniela Schäfer Olstad, Daniel Erlacher, Peter Achermann, Prisca Eser, Matthias Wilhelm
BACKGROUND/AIM: There is increasing popularity for athletes to use heart rate variability (HRV) to tailor training. A time-efficient method is HRV assessment during deep sleep. The aim was to validate the selection of deep sleep segments identified by RR-intervals with simultaneous electroencephalography (EEG) recordings and to compare HRV parameters of these segments with those of standard morning supine measurements. METHODS: In 11 world class alpine- skiers, RR-intervals were monitored during ten nights and simultaneous EEGs were recorded in 2-4 nights...
September 26, 2016: International Journal of Sports Physiology and Performance
Kristin L Jonvik, Jean Nyakayiru, Jan-Willem Van Dijk, Floris C Wardenaar, Luc J C Van Loon, Lex B Verdijk
Although beetroot juice, as a nitrate carrier, is a popular ergogenic supplement amongst athletes, nitrate is consumed through the regular diet as well. We aimed to assess the habitual dietary nitrate intake and identify the main contributing food sources in a large group of highly trained athletes. Dutch highly trained athletes (226 women and 327 men) completed 2-4 web-based 24-h dietary recalls and questionnaires within a 2-4 week period. The nitrate content of food products and food groups was determined systematically based on values found in regulatory reports and scientific literature...
October 21, 2016: International Journal of Sport Nutrition and Exercise Metabolism
Daniel Leightley, Moi Hoon Yap, Jessica Coulson, Mathew Piasecki, James Cameron, Yoann Barnouin, Jon Tobias, Jamie S McPhee
The aim of this study was to compare postural sway during a series of static balancing tasks and during five chair rises between healthy young (mean (SEM) age 26(1) yrs), healthy old (age 67(1) yrs) and master athlete runners (age 67(1) yrs; competing and training for the previous 51(5) yrs) using the Microsoft Kinect One. The healthy old had more sway than young in all balance tasks. The master athletes had similar sway to young during two-leg balancing and one leg standing with eyes open. When balancing on one-leg with eyes closed, both the healthy old and the master athletes had around 17-fold more sway than young...
October 21, 2016: Journal of Aging and Physical Activity
Nicola Giovanelli, Paolo Taboga, Stefano Lazzer
PURPOSE: To investigate changes in running mechanics during a six hours running race. METHODS: Twelve ultra-runners (age: 41.9±5.8 years; body mass: 68.3±12.6 kg; stature: 1.72±0.09 m) were asked to run as many 874 m flat loops as possible in six hours. Running speed, contact (tc) and aerial (ta) times were measured in the first lap and every 30±2 minutes during the race. Peak vertical ground reaction force (Fmax), stride length (SL), vertical downward displacement of the centre of mass (Δz), leg length change (ΔL), vertical (kvert) and leg (kleg) stiffness were then estimated...
September 26, 2016: International Journal of Sports Physiology and Performance
Walter H Reinhart
The hematocrit (Hct) determines the oxygen carrying capacity of blood, but also increases blood viscosity and thus flow resistance. From this dual role the concept of an optimum Hct for tissue oxygenation has been derived. Viscometric studies using the ratio Hct/blood viscosity at high shear rate showed an optimum Hct of 50-60% for red blood cell (RBC) suspensions in plasma. For the perfusion of an artificial microvascular network with 5-70μm channels the optimum Hct was 60-70% for high driving pressures. With lower shear rates or driving pressures the optimum Hct shifted towards lower values...
October 21, 2016: Clinical Hemorheology and Microcirculation
Brun Jean-Frédéric, Varlet-Marie Emmanuelle, Fédou Christine, Raynaud de Mauverger Eric
We investigated to what extent a prediction of the 'ideal' hematocrit based on individual hemorheological profile with an equation of viscosity is relevant in trained athletes, and how the agreement between theoretical and actual values is modified by changes in training volume and performance. Elite soccer players (national level: 18-32 yr, weight 61-83 kg, body mass index 20.9-25.8 kg/m2) were seen twice at one year interval. Hemorheologic parameters were measured with the MT90 viscometer and the Myrenne aggregometer the theoretical bell-shaped curve of hematocrit/viscosity ratio as a function of hematocrit was reconstructed with Quemada's equation using actual plasma viscosity and red cell rigidity to predict hematocrit/viscosity at various hematocrit levels...
October 15, 2016: Clinical Hemorheology and Microcirculation
Brun Jean-Frédéric, Varlet-Marie Emmanuelle, Raynaud de Mauverger Eric
The hemorheological theory of optimal hematocrit suggests that the best value of hematocrit (hct) should be that which results in the highest value of the hematocrit/viscosity (h/η) ratio. Trained athletes compared to sedentary subjects have a lower hct, but a higher h/η, and endurance training reduces the discrepancy between the actual hct and the ⪡ideal⪢ hct that can be predicted with a theoretical curve of h/ηvs hct constructed with Quemada's model. In this study we investigated what becomes this homeostasis of h/η and hct during acute exercise in 19 athletes performing a 25 min exercise test...
October 17, 2016: Clinical Hemorheology and Microcirculation
Michael E Holmstrup, Brock T Jensen, William S Evans, Emily C Marshall
The kettlebell swing (KBS), emphasizing cyclical, explosive hip extension in the horizontal plane, aligns with movement- and velocity-specificity of sprinting. The present study examined the effect of an eight-week KBS intervention on sprinting in recreationally-active females, in comparison to an eight-week intervention using the stiff-legged deadlift (SDL). Following a pre-testing session measuring 30 meter sprint and countermovement vertical jump performance, participants were divided evenly by sprint time into KBS (n=8) and SDL (n=10) cohorts...
2016: International Journal of Exercise Science
Clare F Heisey, J Derek Kingsley
Static stretching was once recognized as a method of preparation for physical activity that would inhibit performance and increase risk of injury. However, a growing body of research suggests that static stretching may not have an inhibitory effect. Regardless, the data have not examined gender differences or the fatigue index (FI) and flexibility effects of static stretching on the back squat over multiple sets. Therefore, the purpose of this study was to examine the relationship between a static-stretch condition (SC) and control condition (CC) on flexibility and the FI of Division I female athletes during 4 sets of the back squat...
2016: International Journal of Exercise Science
Wen-Chyuan Chen, Yi-Ming Chen, Chi-Chang Huang, Yen-Dun Tzeng
Dehydroepiandrosterone (DHEA), the most abundant sex steroid, is primarily secreted by the adrenal gland and a precursor hormone used by athletes for performance enhancement. Whole-body vibration (WBV) is a well-known light-resistance exercise by automatic adaptations to rapid and repeated oscillations from a vibrating platform, which is also a simple and convenient exercise for older adults. However, the potential effects of DHEA supplementation combined with WBV training on to body composition, exercise performance, and hormone regulation are currently unclear...
2016: International Journal of Medical Sciences
Wataru Miyamoto, Shinji Imade, Ken Innami, Hirotaka Kawano, Masato Takao
BACKGROUND: Although early accelerated rehabilitation is recommended for the treatment of acute Achilles tendon rupture, most traditional rehabilitation techniques require some type of brace. METHODS: We retrospectively analyzed 44 feet of 44 patients (25 male and 19 female) with a mean age of 31.8 years who had an acute Achilles tendon rupture related to athletic activity. Patients had been treated by a double side-locking loop suture (SLLS) technique using double antislip knots between stumps and had undergone early accelerated rehabilitation, including active and passive range of motion exercises on the day following the operation and full weight-bearing at 4 weeks...
October 10, 2016: Foot & Ankle International
Zachary C Merz, Ryan Van Patten, John Lace
OBJECTIVE: The current study aimed to assess current broad traumatic brain injury (TBI)-related knowledge in the general public, as well as understanding regarding specific TBI-related conditions including post-concussive syndrome (PCS) and chronic traumatic encephalopathy (CTE). METHODS: Data were collected from 307 domestic and 73 international individuals via online researcher-developed survey instrumentation utilizing the Amazon Mechanical Turk marketplace, a recently developed website that allows for a streamlined process of survey-based participant recruitment and data collection...
October 20, 2016: Archives of Clinical Neuropsychology: the Official Journal of the National Academy of Neuropsychologists
Jin-Young Park, Hyun-Yul Yoo, Seok Won Chung, Seung-Jun Lee, Na Ra Kim, Se-Young Ki, Kyung-Soo Oh
BACKGROUND: Little is known about the clinical characteristics and surgical outcomes of valgus extension overload syndrome (VEOS) in adolescent athletes. We evaluated posteromedial compartment pathology, including combined lesions, and reported the surgical outcomes in adolescent baseball players. METHODS: We retrospectively reviewed the medical records of 13 male adolescent baseball players (mean age, 15.4 years) who underwent arthroscopic olecranon tip resection (n = 9) or staged operations (arthroscopic olecranon tip resection, followed by medial collateral ligament reconstruction 2 weeks later; n = 4)...
October 17, 2016: Journal of Shoulder and Elbow Surgery
Michelle L Delco, John G Kennedy, Lawrence J Bonassar, Lisa A Fortier
The diagnosis of ankle osteoarthritis (OA) is increasing as a result of advancements in non-invasive imaging modalities such as magnetic resonance imaging, improved arthroscopic surgical technology and heightened awareness among clinicians. Unlike OA of the knee, primary or age-related ankle OA is rare, with the majority of ankle OA classified as post-traumatic (PTOA). Ankle trauma, more specifically ankle sprain, is the single most common athletic injury, and no effective therapies are available to prevent or slow progression of PTOA...
October 20, 2016: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Rosario Scarfone, Antonio Ammendolia
BACKGROUND: The aim of this study was to investigate the physiological demands and technical-tactical performances of field players in Italian elite beach soccer team. METHODS: Three official matches of the Italian First Division beach soccer tournament were analyzed to evaluate the heart rate (HR) and time-motion analysis considering: standing, walking, jogging, running and sprinting, and technical-tactical aspects. Repeated-measures ANOVAs were used to determine the effects of time on the physiological measures and time motion analysis...
October 20, 2016: Journal of Sports Medicine and Physical Fitness
Sven Reuter, Andreas B Imhoff, Frank Martetschläger
BACKGROUND: The aim of this study was to systematically review the literature for the impact of rotator cuff tear (RCT) surgery on postoperative sporting activity in professional and recreational athletes. METHODS: To identify any published clinical study on return to sports data for athletes following rotator cuff surgery a systematic search in literature was conducted. Inclusion criteria were partial- and full-thickness rotator cuff tears and any open or arthroscopic RCT surgery in sports participating people...
October 20, 2016: Journal of Sports Medicine and Physical Fitness
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