Read by QxMD icon Read

Performance, athlete

Geoffrey D Abrams, David Feldman, Marc R Safran
Vitamin D is known to be important for calcium homeostasis and bone metabolism. It also has important direct effects on skeletal muscle. Unlike authentic vitamins, which cannot be synthesized in the body, vitamin D is produced in the skin using sunlight. Through its nuclear receptor (ie, vitamin D receptor) located throughout the body, including skeletal muscle, vitamin D initiates genomic and nongenomic pathways regulating multiple actions, including myocyte proliferation and growth. In some studies, vitamin D supplementation has been shown to increase muscle strength, particularly in people who are vitamin D deficient...
March 20, 2018: Journal of the American Academy of Orthopaedic Surgeons
Andrew J Shaw, Stephen A Ingham, Jonathan P Folland
Running downhill, in comparison to running on the flat, appears to involve an exaggerated stretch-shortening cycle (SSC) due to greater impact loads and higher vertical velocity on landing, whilst also incurring a lower metabolic cost. Therefore, downhill running could facilitate higher volumes of training at higher speeds whilst performing an exaggerated SSC, potentially inducing favourable adaptations in running mechanics and running economy (RE). This investigation assessed the efficacy of a supplementary 8-week programme of downhill running as a means of enhancing RE in well-trained distance runners...
March 21, 2018: European Journal of Sport Science
Katie E McGibbon, D B Pyne, M E Shephard, K G Thompson
BACKGROUND: Pacing strategy, or how energy is distributed during exercise, can substantially impact athletic performance and is considered crucial for optimal performance in many sports. This is particularly true in swimming given the highly resistive properties of water and low mechanical efficiency of the swimming action. OBJECTIVES: The aim of this systematic review was to determine the pacing strategies utilised by competitive swimmers in competition and their reproducibility, and to examine the impact of different pacing strategies on kinematic, metabolic and performance variables...
March 20, 2018: Sports Medicine
Khaled Abdullah Al Bishi, Ayman Afify
Background: Anabolic Androgenic Steroids (AAS) are synthetic derivatives of the male sex hormone (testosterone) that are increasingly used by athletes as performance enhancing drugs to increase muscle mass and strength. Multiple health adverse effects may be caused by its non-medical use. Several international and regional studies showed the high prevalence of AAS usage and low level of awareness of it among different populations. Objective: To estimate the prevalence of AAS and to determine the level of awareness toward it among gymnasts in the western province of Riyadh...
December 2017: Electronic Physician
Łukasz A Małek, Marzena Barczuk-Falęcka, Michał Brzewski
The purpose of the study was to analyse whether prolonged and regular physical training in children leads to changes in myocardial systolic deformation and rotational mechanics. For that purpose, cardiac MRI feature tracking was performed retrospectively in 35 pre-adolescent male soccer players and 20 matched controls. There were no changes in global strain, but left ventricular twist and apical rotation were greater in soccer players, which adds to the features of paediatric athlete's heart.
March 21, 2018: Cardiology in the Young
João B Ferreira-Júnior, Ana P M Guttierres, Irismar G A Encarnação, Jorge R P Lima, Diego A Borba, Eduardo D S Freitas, Michael G Bemben, Carlos A Vieira, Martim Bottaro
This study compared the effects of different conditioning activities on the 100-m dash performance of 11 male, high school track and field athletes (mean age = 16.3; SD = 1.2 years). Participants performed a 100-m dash seven minutes after each of four randomized conditioning protocols, with each condition and 100-m dash separated by 3-10 days. The conditioning protocols were (a) control, no conditioning activity; (b) weighted plyometric, three sets of 10 repetitions of alternate leg bounding with additional load of 10% of the body mass; (c) free sprint, two 20-m sprints; and (d) resisted sprint (RS), two 20-m resisted sprints using an elastic tubing tool...
January 1, 2018: Perceptual and Motor Skills
David Perez-Diaz-de-Cerio, Ángela Hernández-Solana, Antonio Valdovinos, Jose Luis Valenzuela
Timing points used in running races and other competition events are generally based on radio-frequency identification (RFID) technology. Athletes' times are calculated via passive RFID tags and reader kits. Specifically, the reader infrastructure needed is complex and requires the deployment of a mat or ramps which hide the receiver antennae under them. Moreover, with the employed tags, it is not possible to transmit additional and dynamic information such as pulse or oximetry monitoring, alarms, etc. In this paper we present a system based on two low complex schemes allowed in Bluetooth Low Energy (BLE): the non-connectable undirected advertisement process and a modified version of scannable undirected advertisement process using the new capabilities present in Bluetooth 5...
March 20, 2018: Sensors
James T Eckner, Alireza Goshtasbi, Kayla Curtis, Aliaksandra Kapshai, Erik Myyra, Lea M Franco, Michael Favre, Jon A Jacobson, James A Ashton-Miller
Greater neck girth and strength may be associated with a lower risk of sport-related concussion due to mitigation of head accelerations by the neck. However, neck strengthening exercise remains unstudied in youth athletes. Therefore, this pilot study assessed the feasibility and effect of targeted neck strengthening exercises in youth athletes. Seventeen participants were allocated to perform 8-wk manual resistance-based neck strengthening (n = 13) or control resistance exercise (n = 4) programs. Before and after the intervention, participants completed laboratory-based assessments of neck size, strength, and head kinematics during standardized test loading in each plane of motion...
April 2018: American Journal of Physical Medicine & Rehabilitation
Victoria Pons, Joan Riera, Xavier Capó, Miquel Martorell, Antoni Sureda, Josep A Tur, Franchek Drobnic, Antoni Pons
Background: Caloric restriction induces mitochondrial biogenesis and improves physical fitness in rodents. We aimed to provide evidence of how caloric restriction affects the body composition and physical performance of trained athletes and to evaluate the possible impact of an every-other-day feeding diet on nutritional deficiencies of micronutrients and essential fatty acids. Methods: The study was performed with 12 healthy male athletes by carrying out a 33% caloric restriction with respect to their usual diet...
2018: Journal of the International Society of Sports Nutrition
Jay R Hoffman, Alyssa Varanoske, Jeffrey R Stout
β-Alanine is one of the more popular sport supplements used by strength/power athletes today. The popularity of β-alanine stems from its ability to enhance intracellular muscle-buffering capacity thereby delaying fatigue during high-intensity exercise by increasing muscle carnosine content. Recent evidence also suggests that elevated carnosine levels may enhance cognitive performance and increase resiliency to stress. These benefits are thought to result from carnosine's potential role as an antioxidant. This review will discuss these new findings including recent investigations examining β-alanine supplementation and increased resiliency to posttraumatic stress and mild traumatic brain injury...
2018: Advances in Food and Nutrition Research
Jill Alexander, Jim Richards, Obed Attah, Sam Cheema, Joanna Snook, Chloe Wisdell, Karen May, James Selfe
Delayed effects of a 20-min crushed ice application on knee joint position sense assessed by a functional task during a re-warming period. INTRODUCTION: The effect of cryotherapy on joint positioning presents conflicting debates as to whether individuals are at an increased risk of injury when returning to play following cryotherapy application at the lower limb. OBJECTIVES: The aim of this study was to investigate whether a 20 min application of crushed ice at the knee affects knee joint kinematics immediately post and up to 20 mins post ice removal, during a small knee bend...
March 6, 2018: Gait & Posture
Helton O Campos, Lucas R Drummond, Quezia T Rodrigues, Frederico S M Machado, Washington Pires, Samuel P Wanner, Cândido C Coimbra
Nitrate (NO3 -) is an ergogenic nutritional supplement that is widely used to improve physical performance. However, the effectiveness of NO3 - supplementation has not been systematically investigated in individuals with different physical fitness levels. The present study analysed whether different fitness levels (non-athletes v. athletes or classification of performance levels), duration of the test used to measure performance (short v. long duration) and the test protocol (time trials v. open-ended tests v...
March 2018: British Journal of Nutrition
Thais Regina de Mattos Lourenco, Priscila Katsumi Matsuoka, Edmund Chada Baracat, Jorge Milhem Haddad
INTRODUCTION AND HYPOTHESIS: People are increasingly aware of healthy lifestyles. Extenuating practice can injure the pelvic floor. Urinary incontinence (UI) is a prevalent condition in women whether they exercise professionally or not. The most common symptom is stress UI. It is reported in a large variety of sports and may interfere with everyday life or training, leading athletes to change or compromise their performance or risk compromising it. We aimed to assess the prevalence of UI in female athletes and to determine whether the type of sport might also influence UI...
March 19, 2018: International Urogynecology Journal
Marie E Boo, J Craig Garrison, Joseph P Hannon, Kalyssa M Creed, Shiho Goto, Angellyn N Grondin, James M Bothwell
Background: Female patients are more likely to suffer a second anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) and return to sport (RTS) compared with healthy female controls. Few studies have examined the energy absorption contribution (EAC) that could lead to this subsequent injury. Hypothesis: The ACLR group would demonstrate an altered EAC between joints (hip, knee, and ankle) but no difference in quadriceps, hip abduction, or hip external rotation (ER) strength at the time of RTS...
March 2018: Orthopaedic Journal of Sports Medicine
Hardaway Chun-Kwan Chan, Weeraya Ka-Yan Ho, Patrick Shu-Hang Yung
Background/Objective: The aim of this study was to examine the effect of sprint cycling training on the intermittent run performance, sprinting speed, and change of direction (COD) ability of recreational intermittent sports athletes. Methods: Sixteen participants participated in the study. The experimental group (EG, n = 8) received a total of 12 sessions of sprint cycling training in a 4-week period and the control group (CG, n = 8) received no training. Both EG and CG were instructed to maintain their daily activity during the 4-week period...
January 2018: Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology
David P Trofa, Joseph M Lombardi, Manish S Noticewala, Christopher S Ahmad
Reconstruction of the ulnar collateral ligament (UCL) remains the gold standard for treating overhead throwing athletes with valgus instability secondary to UCL pathology. Although surgical techniques for reconstruction have evolved over time, current methods allow 90% of patients to return to their preinjury level of activity. Despite encouraging results with reconstruction, UCL repair remains a valuable treatment option for patients with UCL pathology fitting specific criteria. There are a number of advantages associated with a direct repair, and further, the development of collagen-coated sutures for ligament repair augmentation makes this procedure an attractive surgical option under the correct circumstances...
January 2018: Arthroscopy Techniques
Kai Zhang, Jun Wei, Lin Wang
Purpose: To study the effect on HRV of archer athletes one day before competition after three different abdominal respiratory frequencies. Methods: Eight elite archers performed three different respiratory frequency tests, HRV were recorded in pre-, during, and post-frequency control in frequency 16 (F16 group, n = 8), 8 (F8 group, n = 8), and 5 (F5 group, n = 8) times per minute, and hoped to find a respiratory adjust way to reduce stress. RMSSD, RR_triangular index, TP, VLF, LF, HF and LF/HF were analyzed to describe the effect of respiratory frequency...
December 2017: Saudi Journal of Biological Sciences
William R Johnson, Ajmal Mian, Cyril J Donnelly, David Lloyd, Jacqueline Alderson
An understanding of athlete ground reaction forces and moments (GRF/Ms) facilitates the biomechanist's downstream calculation of net joint forces and moments, and associated injury risk. Historically, force platforms used to collect kinetic data are housed within laboratory settings and are not suitable for field-based installation. Given that Newton's Second Law clearly describes the relationship between a body's mass, acceleration, and resultant force, is it possible that marker-based motion capture can represent these parameters sufficiently enough to estimate GRF/Ms, and thereby minimize our reliance on surface embedded force platforms? Specifically, can we successfully use partial least squares (PLS) regression to learn the relationship between motion capture and GRF/Ms data? In total, we analyzed 11 PLS methods and achieved average correlation coefficients of 0...
March 17, 2018: Medical & Biological Engineering & Computing
Enda King, Andrew Franklyn-Miller, Chris Richter, Eamon O'Reilly, Mark Doolan, Kieran Moran, Siobhan Strike, Éanna Falvey
BACKGROUND: Clinical assessments and rehabilitation in athletic groin pain (AGP) have focused on specific anatomical structures and uniplanar impairments rather than whole body movement. OBJECTIVE: To examine the effectiveness of rehabilitation that targeted intersegmental control in patients with AGP and to investigate post rehabilitation changes in cutting biomechanics. METHODS: Two hundred and five patients with AGP were rehabilitated focusing on clinical assessment of intersegmental control, linear running and change of direction mechanics in this prospective case series...
March 17, 2018: British Journal of Sports Medicine
Rhonda Orr, Matthew Grassmayr, Rona Macniven, Anne Grunseit, Mark Halaki, Adrian Bauman
BACKGROUND: This study investigated athlete knowledge of the World Anti-doping Agency (WADA) Prohibited Substances List and the effects of four well-known performance enhancing substances (PES). METHODS: A sample of 1925 elite and sub-elite athletes (mean age 20.6 years) completed a questionnaire about the banned status of 30 substances/methods and their knowledge of the effects of amphetamines, anabolic steroids, growth hormone and erythropoietin. RESULTS: Athletes showed limited understanding of the WADA Prohibited Substances List, scoring 32...
March 15, 2018: International Journal on Drug Policy
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"