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Performance, athlete

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
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
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
Tiffany Wu, Cornelius Olcott, Jason T Lee
No abstract text is available yet for this article.
August 2016: Journal of Vascular Surgery
Yaira Barranco-Ruiz, Antonio Martínez-Amat, Cristina Casals, Jerónimo Aragón-Vela, Silvia Rosillo, Silvana N Gomes, Ana Rivas-García, Rafael Guisado, Jesús R Huertas
The effect of exercise-induced oxidative stress on health and aging is not clearly explained. This study examined the effects of habitual sport practice, age, and submaximal exercise on the blood markers of oxidative stress, muscle damage, and antioxidant response. Seventy-two healthy men were grouped by their habitual sport practice: inactive (<1.5 h/week), recreational (3-8 h/week), and trained athletes (>8 h/week), and further divided by age: young (18-25 years), adult (40-55 years), and senior (>55 years)...
October 20, 2016: Journal of Physiology and Biochemistry
Noortje H Rijken, Remko Soer, Ewold de Maar, Hilco Prins, Wouter B Teeuw, Jan Peuscher, Frits G J Oosterveld
The aim of this pilot study was to investigate the effects of an intervention consisting of mental coaching combined with either electro encephalogram (EEG) alpha power feedback or heart rate variability (HRV) feedback on HRV, EEG outcomes and self-reported factors related to stress, performance, recovery and sleep quality in elite athletes. A prospective pilot study was performed with two distinct cohorts. Soccer players were provided with four sessions of mental coaching combined with daily HRV biofeedback (Group A); track and field athletes were provided with four sessions of mental coaching in combination with daily neurofeedback (Group B)...
October 19, 2016: Applied Psychophysiology and Biofeedback
Breton M Asken, Aliyah R Snyder, M Seth Smith, Jason L Zaremski, Russell M Bauer
OBJECTIVE: The primary goals of this study were (1) to report rates of concussion-like symptoms in healthy adolescent student athletes assessed using the Sport Concussion Assessment Tool, 3rd edition (SCAT3) at baseline, (2) to examine rates of psychiatric diagnoses in this population, and (3) to evaluate effects of baseline symptoms on SCAT3 cognitive and balance performance. METHODS: 349 adolescent student athletes (245 male) were administered the SCAT3 during pre-participation physical examinations...
October 19, 2016: Clinical Neuropsychologist
Cory W Baumann, Dongmin Kwak
PURPOSE: Echinacea is an herbal supplement used by endurance athletes for its performance boosting properties. It is thought that Echinacea improves the blood's oxygen carrying capacity by increasing production of erythropoietin (EPO), a glycoprotein that regulates red blood cell formation. Subsequently, these changes would lead to an overall improvement in maximal oxygen uptake (VO2max) and running economy (RE), two markers of aerobic fitness. The purpose of this review is to briefly discuss the physiological variables associated with distance running performance and how these variables are influenced by Echinacea supplementation...
September 2016: Journal of Exercise Nutrition & Biochemistry
Or Friedman, Ehud Arad, Oded Ben Amotz
In the pursuit of success in sports, some athletes are not deterred by health risks associated with the (mis)use of black market preparations of dubious origin as performance-enhancing agents. Several studies published in the recent years demonstrated that anabolic-androgenic steroids, but also stimulants and growth hormones, are misused by numerous recreational athletes from all over the world. Trenbolone is an anabolic steroid routinely used in the finishing phase of beef production to improve animal performance and feed efficiency...
September 2016: Plastic and Reconstructive Surgery. Global Open
Stephen P Bird, William J Markwick
BACKGROUND AND PURPOSE: Youth participation in basketball is on the rise, with basketball one of the top five participation sports in Australia. With increased participation there is a need for greater awareness of the importance of the pre-participation examination, including musculoskeletal screening and functional performance testing as part of a multidisciplinary approach to reducing the risk for future injuries. As majority of all basketball injuries affect the lower extremities, pre-participation musculoskeletal screening and functional performance testing should assess fundamental movement qualities throughout the kinetic chain with an emphasis on lower extremity force characteristics, specifically eccentric loading tasks...
October 2016: International Journal of Sports Physical Therapy
Andrew M Murray, Thomas W Jones, Cosmin Horobeanu, Anthony P Turner, John Sproule
BACKGROUND: Physiotherapists and other practitioners commonly prescribe foam rolling as an intervention, but the mechanistic effects of this intervention are not known. PURPOSE: The aim of this investigation was to establish if a single bout of foam rolling affects flexibility, skeletal muscle contractility and reflected temperature. METHODS: Twelve adolescent male squash players were evaluated on two separate occasions (treatment and control visits) and were tested on both legs for flexibility of the hip flexors and quadriceps, muscle contractility (as measured by tensiomyography) and temperature of the quadriceps (assessed via thermography) at repeated time points pre- and post a 60s rolling intervention (pre-, immediately post, 5, 10, 15, and 30 minutes post)...
October 2016: International Journal of Sports Physical Therapy
Atsushi Imai, Koji Kaneoka
BACKGROUND: Although it is believed that trunk function is important for athletic performance, few researchers have demonstrated a significant relationship between the trunk function and athletic performance. Recently, the prone plank and side plank tests have been used to assess trunk function. PURPOSE: The purpose of this study was to investigate the relationships between trunk endurance plank tests and athletic performance tests, including whether there is a relationship between long distance running and trunk endurance plank tests in adolescent male soccer players...
October 2016: International Journal of Sports Physical Therapy
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