Selected anthropometrical, muscular architecture, and biomechanical variables as predictors of 50-m performance of front crawl swimming in young male swimmers

2014 ◽  
Vol 29 (5) ◽  
pp. e75-e81 ◽  
Author(s):  
A. Nasirzade ◽  
A. Ehsanbakhsh ◽  
H. Argavani ◽  
A. Sobhkhiz ◽  
M. Aliakbari
Author(s):  
Max I. Phukan ◽  
Rohit K. Thapa ◽  
Gopal Kumar ◽  
Chris Bishop ◽  
Helmi Chaabene ◽  
...  

This study aimed to examine inter-limb jump asymmetries and their association with sport-specific performance in young swimmers. Thirty-eight (male, n = 19; female, n = 19) regional/national level young swimmers (age: 12.3 ± 1.2 years; height: 159.6 ± 8.2 cm; body mass: 52.5 ± 9.2 kg) participated in this study. Inter-limb asymmetries were assessed for single-leg countermovement jump (SLCMJ) and single-leg standing long jump (SLSLJ). Sport-specific performance was evaluated using front crawl (i.e., 50 m and 25 m) and front crawl kick (i.e., 50 m and 25 m). The kappa coefficient revealed a “slight” level of agreement (Κ = 0.156, 0.184, and 0.197 for female, male, and all, respectively) between the direction of asymmetry for SLCMJ and SLSLJ, indicating that asymmetries rarely favored the same limb during both tests. A paired sample t-test showed a significant difference (p = 0.025) between asymmetry scores obtained in SLCMJ and SLSLJ. No significant difference was found in asymmetry scores between males and females (p = 0.099 to 0.977). Additionally, no association between asymmetry scores and sport-specific performance was observed (p > 0.05). Our findings highlight the independent nature of inter-limb asymmetries derived from SLCMJ and SLSLJ among young male and female swimmers. Further, our results suggest no association between jumping asymmetries and sport-specific performance.


2010 ◽  
Vol 22 (2) ◽  
pp. 278-287 ◽  
Author(s):  
Fabrício de Mello Vitor ◽  
Maria Tereza Silveira Böhme

Youth swimming performance may be influenced by anthropometric, physiology and technical factors. The present paper examined the role of these factors in performance of 100m freestyle in swimmers 12–14 years of age (n = 24). Multiple regression analysis (forward method) was used to examine the variance of the 100 meters front crawl. Anaerobic power, swimming index and critical speed explained 88% (p < .05) of the variance in the average speed of 100 meters front crawl among young male pubertal swimmers. To conclude, performance of young swimmers in the 100 meters front crawl is determined predominantly by physiological factors and swimming technique.


Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.


2019 ◽  
Vol 28 (3) ◽  
pp. 548-552
Author(s):  
Andro Košec ◽  
Ivan Kruljac ◽  
Jakov Ajduk

Objective Current recommendations for cochlear hydrops treatment include systemic glucocorticoids and diuretics. Cochlear cells express dopamine receptors, although their role is unknown in the pathophysiology of cochlear hydrops. Case Description We report the case of remission of recurrent right-sided cochlear hydrops in a young male patient treated with bromocriptine due to pituitary macroprolactinoma. Transient improvement was observed after oral steroid and diuretic treatment, but cochlear hydrops recurred until the dose of bromocriptine was increased to 10 mg daily. Conclusion Bromocriptine may stimulate dopamine receptors in cochlear cells with potential therapeutic role in patients with cochlear hydrops. There are no widely accepted and effective treatments for endolymphatic hydrops, and identifying potential new and efficacious therapeutics is of high relevance.


2016 ◽  
Vol 22 ◽  
pp. 233
Author(s):  
Sachin Jain ◽  
Mahender Rajput ◽  
Anshuman Srivastava ◽  
Ramesh Aggarwal ◽  
Subodh Gururani ◽  
...  
Keyword(s):  

2018 ◽  
Vol 24 ◽  
pp. 137-138
Author(s):  
Jahnavi Chakrala ◽  
Syed-azhar Hassan ◽  
Ayesha Siddiqui ◽  
Ramachandra Rahul Chemitiganti ◽  
James Burks
Keyword(s):  

JAMA ◽  
1967 ◽  
Vol 200 (12) ◽  
pp. 1026-1030 ◽  
Author(s):  
S. H. Schuman
Keyword(s):  

2006 ◽  
Vol 76 (5) ◽  
pp. 324-331 ◽  
Author(s):  
Marsh ◽  
Laursen ◽  
Coombes

Erythrocytes transport oxygen to tissues and exercise-induced oxidative stress increases erythrocyte damage and turnover. Increased use of antioxidant supplements may alter protective erythrocyte antioxidant mechanisms during training. Aim of study: To examine the effects of antioxidant supplementation (α-lipoic acid and α-tocopherol) and/or endurance training on the antioxidant defenses of erythrocytes. Methods: Young male Wistar rats were assigned to (1) sedentary; (2) sedentary and antioxidant-supplemented; (3) endurance-trained; or (4) endurance-trained and antioxidant-supplemented groups for 14 weeks. Erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activities, and plasma malondialdehyde (MDA) were then measured. Results: Antioxidant supplementation had no significant effect (p > 0.05) on activities of antioxidant enzymes in sedentary animals. Similarly, endurance training alone also had no effect (p > 0.05). GPX (125.9 ± 2.8 vs. 121.5 ± 3.0 U.gHb–1, p < 0.05) and CAT (6.1 ± 0.2 vs. 5.6 ± 0.2 U.mgHb–1, p < 0.05) activities were increased in supplemented trained animals compared to non-supplemented sedentary animals whereas SOD (61.8 ± 4.3 vs. 52.0 ± 5.2 U.mgHb–1, p < 0.05) activity was decreased. Plasma MDA was not different among groups (p > 0.05). Conclusions: In a rat model, the combination of exercise training and antioxidant supplementation increased antioxidant enzyme activities (GPX, CAT) compared with each individual intervention.


2010 ◽  
Vol 24 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Oscar H. Hernández ◽  
Muriel Vogel-Sprott

A missing stimulus task requires an immediate response to the omission of a regular recurrent stimulus. The task evokes a subclass of event-related potential known as omitted stimulus potential (OSP), which reflects some cognitive processes such as expectancy. The behavioral response to a missing stimulus is referred to as omitted stimulus reaction time (RT). This total RT measure is known to include cognitive and motor components. The cognitive component (premotor RT) is measured by the time from the missing stimulus until the onset of motor action. The motor RT component is measured by the time from the onset of muscle action until the completion of the response. Previous research showed that RT is faster to auditory than to visual stimuli, and that the premotor of RT to a missing auditory stimulus is correlated with the duration of an OSP. Although this observation suggests that similar cognitive processes might underlie these two measures, no research has tested this possibility. If similar cognitive processes are involved in the premotor RT and OSP duration, these two measures should be correlated in visual and somatosensory modalities, and the premotor RT to missing auditory stimuli should be fastest. This hypothesis was tested in 17 young male volunteers who performed a missing stimulus task, who were presented with trains of auditory, visual, and somatosensory stimuli and the OSP and RT measures were recorded. The results showed that premotor RT and OSP duration were consistently related, and that both measures were shorter with respect to auditory stimuli than to visual or somatosensory stimuli. This provides the first evidence that the premotor RT is related to an attribute of the OSP in all three sensory modalities.


1994 ◽  
Vol 39 (4) ◽  
pp. 436-436
Author(s):  
Terri Gullickson ◽  
Pamela Ramser

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