Read by QxMD icon Read


Simon F Schoeller, Eric E Keaveny
Swimming cells and microorganisms are as diverse in their collective dynamics as they are in their individual shapes and propulsion mechanisms. Even for sperm cells, which have a stereotyped shape consisting of a cell body connected to a flexible flagellum, a wide range of collective dynamics is observed spanning from the formation of tightly packed groups to the display of larger-scale, turbulence-like motion. Using a detailed mathematical model that resolves flagellum dynamics, we perform simulations of sperm suspensions containing up to 1000 cells and explore the connection between individual and collective dynamics...
March 2018: Journal of the Royal Society, Interface
Mathias Samson, Tony Monnet, Anthony Bernard, Patrick Lacouture, Laurent David
Tethered swimming is a method often used to measure or enhance the physical and technical resources of swimmers. Although it is highlighted that the technique used in tethered swimming is probably different from that used in free conditions, there are few comparative studies on this subject. The current study aims to compare fully tethered and free swimming based on kinematic hand parameters (orientation, velocity and acceleration of the hand, sweepback and angle of attack), which are known to act directly on the generation of propulsive forces...
March 21, 2018: Sports Biomechanics
B Steelant, V Hox, L Van Gerven, E Dilissen, E Dekimpe, A Kasran, S Aertgeerts, V Van Belle, K Peers, L J Dupont, P W Hellings, D M Bullens, S F Seys
BACKGROUND: A high burden of lower airway symptoms is found in elite swimmers. To what extent elite swimmers suffer from upper airway symptoms and how these associate with nasal inflammation is less clear. We here aimed to evaluate upper airway symptoms and nasal inflammation in elite athletes. METHODOLOGY: Elite swimmers, indoor athletes and age-matched controls were recruited. Upper airway symptoms were assessed by sino-nasal outcome test (SNOT)-22 questionnaire...
March 21, 2018: Rhinology
Markus Selmke, Utsab Khadka, Andreas P Bregulla, Frank Cichos, Haw Yang
Photon nudging is a new experimental method which enables the force-free manipulation and localization of individual self-propelled artificial micro-swimmers in fluidic environments. It uses a weak laser to stochastically and adaptively turn on and off the swimmer's propulsion when the swimmer, through rotational diffusion, points towards or away from its target, respectively. This contribution presents a theoretical framework for the statistics of both 2D and 3D controls. The main results are: the on- and off-time distributions for the controlling laser, the arrival time statistics for the swimmer to reach a remote target, and how the experimentally accessible control parameters influence the control, e...
March 21, 2018: Physical Chemistry Chemical Physics: PCCP
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
Olivier Castagna, Sébastien de Maistre, Bruno Schmid, Delphine Caudal, Jacques Regnard
In healthy divers, the occurrence of immersion pulmonary oedema (IPE) is commonly caused by contributory factors including strenuous exercise, cold water and negative-pressure breathing. Contrary to this established paradigm, this case reports on a 26-year-old, well-trained combat swimmer who succumbed to acute IPE during static immersion in temperate (21°C) water, while using a front-mounted counterlung rebreather. The incident occurred during repeated depth-controlled ascent practice at the French military diving school...
March 31, 2018: Diving and Hyperbaric Medicine: the Journal of the South Pacific Underwater Medicine Society
Tomohiro Gonjo, Carla McCabe, Ana Sousa, João Ribeiro, Ricardo J Fernandes, João Paulo Vilas-Boas, Ross Sanders
PURPOSE: The purpose of this study was to determine kinematic and energetic differences between front crawl and backstroke performed at the same aerobic speeds. METHODS: Ten male competitive swimmers performed front crawl and backstroke at a pre-determined sub-anaerobic threshold speed to assess energy cost (through oxygen uptake measurement) and kinematics (using three-dimensional videography to determine stroke frequency and length, intra-cycle velocity fluctuation, three-dimensional wrist and ankle speeds, and vertical and lateral ankle range of motion)...
March 19, 2018: European Journal of Applied Physiology
Z Checinska-Maciejewska, E Miller-Kasprzak, A Checinska, E Korek, M Gibas-Dorna, A Adamczak-Ratajczak, P Bogdanski, H Krauss
It has been proposed that regular cold swimming is associated with health benefits. However, the effect of cold adaptation on particular cardiovascular risk factors, within a single swimming season, remains unknown. Our aim was to evaluate the impact of cold water swimming on the seasonal changes in lipid profile and on apolipoprotein and homocysteine concentration in 34 cold water swimmers (CWS) aged 48 - 68 years. Blood samples were collected at the beginning (October), the middle (January), and the end (April) of the swimming season...
December 2017: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
Thomas W Gaither, Mohannad A Awad, Gregory P Murphy, Ian Metzler, Thomas Sanford, Michael L Eisenberg, Siobhan Sutcliffe, E Charles Osterberg, Benjamin N Breyer
BACKGROUND: Bicycle riding has become an increasingly popular mode of transportation and exercise, especially among women, and previous studies have demonstrated a relationship between cycling and sexual dysfunction, albeit using non-validated questionnaires. AIM: We aimed to explore the relationship between cycling and sexual and urinary dysfunction. METHODS: Cyclists were recruited to complete a survey through Facebook advertisements and outreach to sporting clubs across 5 English-speaking countries...
March 6, 2018: Journal of Sexual Medicine
Adyant Agrawal, Sujin B Babu
We study the cooperation and segregation dynamics in a bimotility mixture of microorganisms which swim at low Reynolds numbers via periodic deformations along the body. We employ a multiparticle collision dynamics method to simulate a two component mixture of artificial swimmers, termed as Taylor lines, which differ from each other only in the propulsion speed. The analysis reveals that a contribution of slower swimmers towards clustering, on average, is much larger as compared to the faster ones. We notice distinctive self-organizing dynamics, depending on the percentage difference in the speed of the two kinds...
February 2018: Physical Review. E
Henning Reinken, Sabine H L Klapp, Markus Bär, Sebastian Heidenreich
In this paper, we systematically derive a fourth-order continuum theory capable of reproducing mesoscale turbulence in a three-dimensional suspension of microswimmers. We start from overdamped Langevin equations for a generic microscopic model (pushers or pullers), which include hydrodynamic interactions on both small length scales (polar alignment of neighboring swimmers) and large length scales, where the solvent flow interacts with the order parameter field. The flow field is determined via the Stokes equation supplemented by an ansatz for the stress tensor...
February 2018: Physical Review. E
Mohd Suhail Rizvi, Alexander Farutin, Chaouqi Misbah
The self-propelled microswimmers have recently attracted considerable attention as model systems for biological cell migration as well as artificial micromachines. A simple and well-studied microswimmer model consists of three identical spherical beads joined by two springs in a linear fashion with active oscillatory forces being applied on the beads to generate self-propulsion. We have extended this linear microswimmer configuration to a triangular geometry where the three beads are connected by three identical springs in an equilateral triangular manner...
February 2018: Physical Review. E
Muaz Belviranli, Nilsel Okudan, Nuran Karakuyu
The objective of this investigation was to compare irisin concentration and its relation with oxidative stress markers, antioxidant enzymes and element levels in both male adolescent swimmers and sedentary controls. Twelve male swimmers aged between 11 and 18 years, who performed regular swimming training for at least 2 years and 12 age- and gender-matched sedentary controls participated in this study. After anthropometric measurements were performed, fasting venous blood samples were taken at rest. Irisin, malondialdehyde (MDA) as a marker of oxidative stress, superoxide dismutase (SOD) as a marker of antioxidant enzyme and elements (Zn, Cu, Se, Cr, Ni, Al, Fe) were analyzed in these samples...
March 16, 2018: Hormone Molecular Biology and Clinical Investigation
Senda Sammoud, Alan Michael Nevill, Yassine Negra, Raja Bouguezzi, Helmi Chaabene, Younés Hachana
This study aimed to estimate the optimal body size, limb segment length, and girth or breadth ratios of 100-m breaststroke performance in youth swimmers. In total, 59 swimmers [male: n = 39, age = 11.5 (1.3) y; female: n = 20, age = 12.0 (1.0) y] participated in this study. To identify size/shape characteristics associated with 100-m breaststroke swimming performance, we computed a multiplicative allometric log-linear regression model, which was refined using backward elimination. Results showed that the 100-m breaststroke performance revealed a significant negative association with fat mass and a significant positive association with the segment length ratio (arm ratio = hand length/forearm length) and limb girth ratio (girth ratio = forearm girth/wrist girth)...
March 16, 2018: Pediatric Exercise Science
Asunción Ferri-Morales, Marcus Vinicius Nascimento-Ferreira, Dimitris Vlachopoulos, Esther Ubago-Guisado, Ana Torres-Costoso, Augusto Cesar F De Moraes, Alan R Barker, Luis A Moreno, Vicente Martínez-Vizcaino, Luis Gracia-Marco
PURPOSE: To examine the intermethods agreement of dual-energy X-ray absorptiometry (DXA) and foot-to-foot bioelectrical impedance analysis (BIA) to assess the percentage of body fat (%BF) in young male athletes using air-displacement plethysmography (ADP) as the reference method. METHODS: Standard measurement protocols were carried out in 104 athletes (40 swimmers, 37 footballers, and 27 cyclists, aged 12-14 y). RESULTS: Age-adjusted %BF ADP and %BF BIA were significantly higher in swimmers than footballers...
March 15, 2018: Pediatric Exercise Science
Di Du, Elaa Hilou, Sibani Lisa Biswal
Swimming at low Reynolds number is typically dominated by a large viscous drag, therefore microscale swimmers require non-reciprocal body deformation to generate locomotion. Purcell described a simple mechanical swimmer at the microscale consisting of three rigid components connected together with two hinges. Here we present a simple microswimmer consisting of two rigid paramagnetic particles with different sizes. When placed in an eccentric magnetic field, this simple microswimmer exhibits non-reciprocal body motion and its swimming locomotion can be directed in a controllable manner...
March 15, 2018: Soft Matter
Michael D Kennedy, Jessie M S Gill, Alastair N H Hodges
Background: Diagnosing Airway hyper-responsiveness (AHR) requires bronchial provocation tests that are performed at rest and after exercise or hyperventilation in either a lab or field setting. Presently, it is unclear whether the proposed AHR field test for swimming induces sufficient provocation due to lack of intensity. Thus we aimed to examine how the 8 minute field swim test compared to all out racing and a lower intensity practice exposure affected AHR. We hypothesized that the race would affect AHR the most thereby highlighting the importance of maximal effort in swim AHR...
June 2017: Journal of Exercise Science and Fitness
Dayanne S Lima-Borges, Paula F Martinez, Luiz Carlos M Vanderlei, Fernando S S Barbosa, Silvio A Oliveira-Junior
OBJECTIVES: Young athletes' participation in competitive sports is becoming increasingly common, and this increased involvement raises concerns about the occurrence of overtraining and sports injuries. Since these issues are poorly understood, this study analyzed heart rate variability, stress/recovery relationship, and sports injury incidence during a training macrocycle of young sprint and endurance swimmers. METHODS: Thirty teenage swimmers (aged 12 to 17 years) were divided into two groups as follows: Sprint (n=17) and Endurance (n=13)...
March 14, 2018: Physician and Sportsmedicine
Silvester Liposek, Natasa Zenic, Jose M Saavedra, Damir Sekulic, Jelena Rodek, Miha Marinsek, Dorica Sajber
Although coaching is considered an important determinant of athletes' potential doping behavior (PDB), there is an evident lack of studies that have examined coaching-strategy-and-training-methodology (CS&TM) in relation to PDB. This study was aimed to identify the specific associations that may exist between CS&TM -factors and other factors, and PDB in high-level swimming. The sample comprised 94 swimmers (35 females; 19.7 ± 2.3 years of age) and consisted of swimmers older than 18 years who participated in the 2017 National Championship...
March 2018: Journal of Sports Science & Medicine
João Cavaleiro Rufo, Inês Paciência, Diana Silva, Carla Martins, Joana Madureira, Eduardo de Oliveira Fernandes, Patrícia Padrão, Pedro Moreira, Luís Delgado, André Moreira
BACKGROUND: Endurance swimming exercises coupled to disinfection by-products exposure has been associated with increased airways dysfunction and neurogenic inflammation in elite swimmers. However, the impact of swimming pool exposure at a recreational level on autonomic activity has never been explored. Therefore, this study aimed to investigate how swimming pool attendance is influencing lung and autonomic function in school-aged children. METHODS: A total of 858 children enrolled a cross sectional survey...
2018: PloS One
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"