473 research outputs found

    An examination of training on the VertiMax Resisted Jumping Device for improvements in lower body power in highly trained college athletes

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    Training to develop superior muscular power has become a key component to most progressive sport conditioning programs. Conventional resistance training, plyometrics, and speed/agility modalities have all been employed in an effort to realize superlative combinations of training stimuli. New training devices such as the VertiMax resisted jump trainer are marketed as a means of improving lower body reactive power. The purpose of this study was to evaluate the effectiveness of the VertiMax, in combination with traditional training modalities, for improvements in lower body power among highly trained athletes. Forty men and women Division I collegiate athletes representing the sports of baseball, basketball, soccer, gymnastics, and track completed a 12-week mixed-methods training program. Two groups were constructed with both groups performing the same conventional resistance training and strength training exercises. The training control group performed traditional plyometric exercises while the experimental group performed similar loaded jump training on the VertiMax. Lower body power was measured before and after the training program by the TENDO FiTROdyne Powerlizer and statistically compared for differences between groups. Data analyses identified a significant (p < 0.05) and meaningful difference between power development among the 2 groups, with the VertiMax eliciting a greater treatment effect (effect size = 0.54) over conventional resistance and plyometric training alone (effect size = 0.09). These data convincingly demonstrate that the VertiMax represents an effective strategy for developing lower body power among trained college athletes, when combined with traditional strength and conditioning approaches

    Hydrodynamics in evaporate-bearing fine-grained successions investigated through an interdisciplinary approach : A test study in southern Italy-hydrogeological behaviour of heterogeneous low-permeability media

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    Messinian evaporates are widely distributed in the Mediterranean Sea as outcropping sediments in small marginal basins and in marine cores. Progressive filling of subbasins led to the formation of complex aquifer systems in different regions where hypersaline and fresh water coexist and interact in different manner. It also generates a significant diversification of groundwater hydrochemical signature and different microbial communities. In the case study, the hydrogeology and hydrochemistry of the whole system are influenced by good hydraulic connection between the shallower pyroclastic horizon and the underlying evaporate-bearing fine-grained Messinian succession. This is demonstrated by the merge of hydrogeological, chemical, isotopic, and microbiological data. No mixing with deep ascending waters has been observed. As shown by geophysical, hydraulic, and microbiological investigations, the hydraulic heterogeneity of the Messinian bedrock, mainly due to karstified evaporitic interstrata/lenses, causes the hydraulic head to significantly vary with depth. Somewhere, the head increases with the depth's increase and artesian flow conditions are locally observed. Moreover, the metagenomic investigations demonstrated the existence of a poor hydraulic connection within the evaporate-bearing fine-grained succession at metric and decametric scales, therefore leading to a patchwork of geochemical (and microbiological) subenvironments

    The effectiveness of injury prevention programs to modify risk factors for non-contact anterior cruciate ligament and hamstring injuries in uninjured team sports athletes: A systematic review

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    Background Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes. Objective The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes. Data Sources PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles. Main Results Nineteen studies were included in this review. Four assessment categories: i) landing, ii) side cutting, iii) stop-jump, and iv) muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position. Conclusions Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors

    Comparison between nasopharyngeal swab and nasal wash, using culture and PCR, in the detection of potential respiratory pathogens

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    <p>Abstract</p> <p>Background</p> <p>Nasopharyngeal carriage of potential pathogens is important as it is both the major source of transmission and the prerequisite of invasive disease. New methods for detecting carriage could improve comfort, accuracy and laboratory utility. The aims of this study were to compare the sensitivities of a nasopharyngeal swab (NPS) and a nasal wash (NW) in detecting potential respiratory pathogens in healthy adults using microbiological culture and PCR.</p> <p>Results</p> <p>Healthy volunteers attended for nasal washing and brushing of the posterior nasopharynx. Conventional and real-time PCR were used to detect pneumococcus and meningococcus. Statistical differences between the two nasal sampling methods were determined using a nonparametric Mann-Whitney U test; differences between culture and PCR methods were determined using the McNemar test.</p> <p>Nasal washing was more comfortable for volunteers than swabbing (n = 24). In detection by culture, the NW was significantly more likely to detect pathogens than the NPS (<it>p </it>< 0.00001). Overall, there was a low carriage rate of pathogens in this sample; no significant difference was seen in the detection of bacteria between culture and PCR methods.</p> <p>Conclusions</p> <p>Nasal washing and PCR may provide effective alternatives to nasopharyngeal swabbing and classical microbiology, respectively.</p

    Effects of protein–carbohydrate supplementation on immunity and resistance training outcomes: a double-blind, randomized, controlled clinical trial

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    Purpose: To examine the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on resistance training outcomes, body composition, muscle thickness, blood indices of health and salivary human neutrophil peptides (HNP1-3), as reference of humoral immunity followed an 8-week resistance training program in college athletes. Methods: Twenty-seven recreationally physically active males and females (n = 9 per treatment) were randomly assigned to one of the three groups: hydrolyzed beef protein, whey protein, or non-protein isoenergetic carbohydrate. Treatment consisted of ingesting 20 g of supplement, mixed with orange juice, once a day immediately post-workout or before breakfast on non-training days. Measurements were performed pre- and post-intervention on total load (kg) lifted at the first and last workout, body composition (via plethysmography) vastus medialis thickness (mm) (via ultrasonography), and blood indices of health. Salivary HNP1-3 were determined before and after performing the first and last workout. Results: Salivary concentration and secretion rates of the HNP1-3 decreased in the beef condition only from pre-first-workout (1.90 ± 0.83 μg/mL; 2.95 ± 2.83 μg/min, respectively) to pre-last-workout (0.92 ± 0.63 μg/mL, p = 0.025, d = 1.03; 0.76 ± 0.74 μg/min, p = 0.049, d = 0.95), and post-last-workout (0.95 ± 0.60 μg/mL, p = 0.032, d = 1.00; 0.59 ± 0.52 μg/min, p = 0.027, d = 1.02). No other significant differences between groups were observed. Conclusions: Supplementation with a carbohydrate–protein beverage may support resistance training outcomes in a comparable way as the ingestion of only carbohydrate. Furthermore, the ingestion of 20 g of hydrolyzed beef protein resulted in a decreased level and secretion rates of the HNP1-3 from baseline with no negative effect on blood indices of health

    Validity and reliability of a novel optoelectronic device to measure movement velocity, force and power during the back squat exercise

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    This study analysed the validity and reliability of a new optoelectronic device (Velowin) for the measurement of vertical displacement and velocity as well as to estimate force and mechanical power. Eleven trained males with Mean (SD) age = 27.4 (4.8) years, completed an incremental squat exercise test with 5 different loads (<30 – 90% of their 1−repetition maximum) while displacement and vertical velocity of the barbell were simultaneously measured using an integrated 3D system (3D motion capture system + force platform) and Velowin. Substantial to almost perfect correlation (concordance correlation coefficient = 0.75 – 0.96), root mean square error as coefficient of variation ±90% confidence interval 10% and good to excellent intraclass correlation coefficient = 0.84 – 0.99 were determined for all the variables. Passing and Bablock regression methods revealed no differences for average velocity. However, significant but consistent bias were determined for average or peak force and power while systematic and not proportional bias was found for displacement. In conclusion, Velowin, holds some potential advantages over traditionally used accelerometer or linear transducers, represents a valid and reliable alternative to monitor vertical displacement and velocity as well as to estimate average force and mechanical power during the squat exercise

    Neuromuscular training improves movement competency and physical performance measures in 11-13 year old female netball athletes

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    The purpose of this study was to examine the effects of a neuromuscular training program on movement competency and measures of physical performance in youth female netball players. It was hypothesized that significant improvements would be found in movement competency and physical performance measures following the intervention. Twenty-three junior female netball players (age, 12.17 ± 0.94 yrs; height, 1.63 ± 0.08 m; weight, 51.81 ± 8.45 kg) completed a test battery before and after a six-week training intervention. 13 of these athletes underwent six weeks of neuromuscular training, which incorporated plyometrics and resistance training. Trained athletes showed significant improvements in 20 m sprint time, 505 agility time, countermovement jump height and peak power (p ≤ 0.05, g \u3e 0.8). Additionally, trained athletes significantly improved their score in the Netball Movement Screening Tool (NMST) (p \u3c 0.05, g \u3e -1.30); while the athletes also demonstrated increased reach in the anterior and posteromedial directions for the right and left leg, and in the posterolateral direction for the left leg only in the Star Excursion Balance Test (SEBT) (p \u3c 0.05, g \u3e -0.03). Control subjects did not exhibit any significant changes during the 6-week period. Significant negative correlations were found between improved score on the NMST and decreased 5 m, 10 m and 20 m sprint time, and 505 change of direction time (r \u3e 0.4, p ≤ 0.05). Results of the study affirm the hypothesis that a six-week neuromuscular training intervention can improve performance and movement competency in youth netball player
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