Search

The aim was to investigate the potential differences in muscle (vastus lateralis) and cerebral (prefrontal cortex) oxygenation levels as well as in the number of repetitions and total work output between isokinetic eccentric and concentric exercise at a moderate relative intensity until exhaustion. Ten recreationally active young men underwent two isokinetic exercise sessions either concentric or eccentric, one on each randomly selected leg. The protocols were performed at 60°/s and an intensity corresponding to 60% of the maximal voluntary contraction (MVC) of each contraction type. Concentric torque was significantly lower compared to eccentric torque in both peak values and at values corresponding to 60% of MVC [230 ± 18 Nm vs. 276 ± 19 Nm (P = .014) and 137 ± 12 Nm vs. 168 ± 11 Nm, respectively (P = .010)]. The participants performed 40% more contractions during eccentric compared to concentric exercise [122 ± 15 vs. 78 ± 7, respectively]. No differences were found in the levels of oxyhaemoglobin, deoxyhemoglobin, total haemoglobin and tissue saturation index when eccentric and eccentric exercise regimes were compared (all P > .05). Our results demonstrate that eccentric exercise of moderate intensity leads to greater resistance to fatigue and more work output compared to concentric exercise, despite the comparable muscle and cerebral oxygenation levels. © 2021 Informa UK Limited, trading as Taylor & Francis Group.

Background/objective: Aetiology and significance of exercise-induced troponin release remains a contentious issue. We investigated the effect of a 28 km mountain run on cardiac troponin I (cTnI), in relation to training, performance, nutritional, biochemical and echocardiography variables, in a group of 25 recreational male master athletes. Material and methods: A comprehensive list of variables related with nutrition, training, performance and echocardiography, was collected pre- and post-race. Twenty-four months later, outcomes regarding cardiovascular events were obtained. Results: Serum cTnI values were increased after the race, with mean values rising from 7.2 ± 2.2 (before) to 80.0 ± 33.2 ng/L (post race), (p < 0.001) and 23/25(92%) exceeding Upper Reference limit (50 ng/L). Echocardiography did not reveal significant alterations, or correlations with cTnI values. The percentage difference in hs-cTnI concentrations pre- and post-race correlated positively with age, race-induced changes of selected muscle damage indices, resistance training volume and negatively with endurance capacity and training volume (r: −0.727 to 0.725, p < 0.05). All athletes reported no cardiovascular event during the 24-month period post-race. Conclusion: cTnI elevation induced by a 28 km mountain running race was not correlated with echocardiographic, nutritional parameters and was less pronounced in athletes with larger endurance training history, in contrast with resistance training and age. © 2022 Informa UK Limited, trading as Taylor & Francis Group.

BACKGROUND: Volleyball players as overhead athletes have the highest risk of developing scapular dyskinesis. The kinetic chain exercise-approach has gained a lot of attention because of its claims to provide an improved motor control and scapular kinematics. A form of cross exercise, known as mirror therapy, may enhance the effects of a kinetic-chain-approach on scapular posture, upper and lower limb performance. The aim of this study was to investigate the adjunctive benefits of mirror cross education in a kinetic chain approach, in volleyball athletes with SD. METHODS: Thirty-nine professional volleyball athletes were randomly assigned to three groups of 13 each, two experimental, the mirror cross education and kinetic chain approach, and one control. Both experimental groups performed a kinetic chain approach program, however, the mirror cross education group performed the exercise program with the addition of two mirrors that allowed athletes to observe their opposite non-dyskinetic scapula. Scapular posture asymmetries in cm, the Y-Balance and the Upper-Quarter Y-Balance after normalizing by limb length the reach distance in each direction, were assessed before and after performing each intervention for 6 weeks. RESULTS: 3×2 two-way Mixed ANOVAs detected significant interactions on scapular posture (P=0.001) on both experimental groups when compared with the control. The Y-Balance and the Upper Quarter Y-Balance scores at both mirror cross education and kinetic chain approach groups showed significant differences when compared with the control (P

BACKGROUND: Data about lower extremities' strength and power asymmetries in fencers, and their relationships to fencing performance are limited and inconsistent. OBJECTIVE: The aim of the present study was to investigate asymmetries, between dominant (D) and non-dom (ND) legs of elite young male and female fencers, in relation to performance in fencing specific tests. METHODS: Anthropometric characteristics, unilateral vertical-horizontal jumping, isokinetic strength, lunge and step lunge performances were evaluated in 16 male and 22 female elite fencers. RESULTS: Significant differences between genders were found for all anthropometric measurements (p< 0.05). No significant bilateral asymmetries and gender x laterality effects were observed (p> 0.05). Fencing performance was negatively correlated with the D leg's flexion/extension (F/E) ratio at 300°s (r:-0.564 to-0.619, p< 0.05). In addition, D leg's F/E ratio at 300°s was positively related to lung peak velocity and power in female fencers (r: 0.562-0.649; p< 0.05). Finally, only in female fencers, unilateral triple hop distance was significantly related to lung peak velocity and power (r: 0.442-0.500; p< 0.05). CONCLUSIONS: The results of the present study suggest that the differential activation/movement pattern of the D and ND leg muscles do not lead to anatomical, dynamic and functional lower extremities asymmetries. © 2021-IOS Press. All rights reserved.

Relative age effects are developmental advantages that children born in the months following a particular cut-off date have over their younger counterparts. Evidence of relative age effect is well demonstrated in a variety of team sports, however, only few studies have examined the presence of relative age effects in young female volleyball players. The purpose of this study was to determine the prevalence of relative age effect, and the quarterly differences on anthropometric and physiological characteristics in a group of young female volleyball players 13-14 years old. In total, 389 female high-level volleyball players (age = 14.18±5.45 years, height = 167±0.07 cm, weight = 57.05±9.48 kg, and BMI = 20.28±2.76), participated in a national age-group selection training camp and were divided into two age groups (AG13, n =127) and (AG14, n = 262). To define the distribution in the birth quarter, volleyball players were separated into 4 groups according to the date of birth: T1 (January–March), T2 (April–June), T3 (July–September) and T4 (October–December). The relative age effect was not proven to be present between the first and the last age groups. For the AG13, 52.63% of the volleyball players were born in the first quarter, while 15.61% were born in the fourth quarter. The relative values for AG14 were 65.9% and 15.65% (χ2 = 12.486, p = 0.187) respectively. The findings of this study demonstrate that RAE has little effect on physiological markers in this female age group, with the development of strong functional drills in the sport being the top focus. Future studies are needed to identify not only the causes but also the consequences of the RAE in female volleyball players. © JPES.

The aim of the present study was to study the effects of cycling and pure concentric and pure eccentric high-intensity interval exercise (HIIE) on skeletal muscle (i.e., vastus lateralis) and cerebral oxygenation. Twelve healthy males (n = 12, age 26 ± 1 yr, body mass 78 ± 2 kg, height 176 ± 2 cm, body fat 17 ± 1% of body mass) performed, in a random order, cycling exercise and isokinetic concentric and eccentric exercise. The isokinetic exercises were performed on each randomly selected leg. The muscle and the cerebral oxygenation were assessed by measuring oxyhemoglobin, deoxyhemoglobin, total hemoglobin, and tissue saturation index. During the cycling exercise, participants performed seven sets of seven seconds maximal intensity using a load equal to 7.5% of their body mass while, during isokinetic concentric and eccentric exercise, they were performed seven sets of five maximal muscle contractions. In all conditions, a 15 s rest was adopted between sets. The cycling HIIE caused greater fatigue (i.e., greater decline in fatigue index) compared to pure concentric and pure eccentric isokinetic exercise. Muscle oxygenation was significantly reduced during HIIE in the three exercise modes, with no difference between them. Cerebral oxygenation was affected only marginally during cycling exercise, while no difference was observed between conditions. It is concluded that a greater volume of either concentric or eccentric isokinetic maximal intensity exercise is needed to cause exhaustion which, in turn, may cause greater alterations in skeletal muscle and cerebral oxygenation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Chryssanthopoulos, C, Tsolakis, C, Bottoms, L, Toubekis, A, Zacharogiannis, E, Pafili, Z, and Maridaki, M. Effect of a carbohydrate-electrolyte solution on fluid balance and performance at a thermoneutral environment in international-level fencers. J Strength Cond Res 34(1): 152-161, 2020-The purpose of the study was to examine a possible effect of a carbohydrate-electrolyte (CHO-E) solution on fluid balance and performance in fencing at a thermoneutral environment. Sixteen fencers performed two 120-minute training sessions separated by 7-14 days under similar environmental conditions (temperature: 20.3° C and humidity: 45-47%). Each session consisted of 60-minute conditioning exercises followed by 10 bouts of 3 minutes against the same opponent with 3-minute interval between each bout. Participants ingested at regular intervals either a 6% CHO-E solution or an artificially sweetened water (PL) in a counterbalanced order. No difference was observed between conditions in the heart rate responses, perceived exertion, changes in plasma volume, urine specific gravity, number of bouts won or lost, or points for and against. Considerable variability was observed in body mass changes that revealed significant differences at the time level (i.e., pre- vs. post-exercise) (F1,15 = 9.31, p = 0.008, η = 0.38), whereas no difference was found between conditions (i.e., CHO-E vs. PL) (F1,15 = 0.43, p = 0.52, η = 0.03) and conditions × time interaction (F1,15 = 3.57, p = 0.078, η = 0.19). Fluid loss was not significantly different between conditions (p = 0.08, d = 0.47). The blood glucose level was higher (p < 0.01) after exercise in CHO-E, whereas the blood lactate level was similar between conditions. In conclusion, the CHO-E solution was as effective as the artificially sweetened water in terms of fluid balance and fencing performance at a thermoneutral environment. Because of large individual variability, fencers should monitor their fluid intake and body fluid loss in training and competition.

Fencing is a combat sport, where beyond physical and physiological demands, strategy and tactics are crucial factors in order to identify fencers’ performance. Fencers’ tactical movements can be separated in preparatory actions and final actual offensive (attacks) and defensive (parries and counterattacks) actions. The aim of this study is to analyse the tactical choices of elite male and female qualifiers foil fencers in finals and semi-finals bouts of the 2016-17 FIE (International Fencing Federation) competitions. Attacking and defending points were recorded, compared with the type of point, the section thrusts were landed and the time period they were noted. The present study revealed significant difference between offensive and defensive efficacy in both male (p

Aim of the study was to compare the isometric strength of flexors and extensors trunk muscles between male and female elite adolescent athletes of different age and training experience. Absolute and relative trunk muscle isometric peak extension (PTE) and flexion (PTF) torque, as well as flexion/extension (F/E) ratio were evaluated in 388 elite adolescent athletes 188 males (Age: 15.4±1.8 years, Body height: 175.5±11.2 cm, Body mass: 68.8±14.5 kg, BMI: 22.1±0.3 kg/m2) and 207 females (Age: 15.1±1.6 years, Body height: 166.8±7.8 cm, Body mass: 60.8±8.4 kg and BMI: 21.8±0.4 kg/m2). Participants were assigned into seven different groups according to their sport specialisation (oars-paddle, swimming, contact–combat, team, racket, winter and mixed other sports). Significant effect of age (η2: 0.077–0.112, p

Bogdanis, GC, Donti, O, Tsolakis, C, Smilios, I, and Bishop, DJ. Intermittent but not continuous static stretching improves subsequent vertical jump performance in flexibility-trained athletes. J Strength Cond Res 33(1): 203-210, 2019 - This study examined changes in countermovement jump (CMJ) height after an intermittent or a continuous static stretching protocol of equal total duration. Sixteen male, elite-level gymnasts performed 90 seconds of intermittent (3 × 30 seconds with 30 seconds rest) or continuous stretching (90 seconds) of the quadriceps muscle. A single-leg stretching and jumping design was used, with the contralateral limb serving as a control. The same individuals performed both conditions with alternate legs in a randomized, counterbalanced order. One-leg CMJ height was measured for the stretched and the control leg after warm-up, immediately after stretching, and at regular intervals for 10 minutes after stretching. Range of motion (ROM) of the hip and knee joints was measured before, after, and 10 minutes poststretching. Compared with the control leg, intermittent stretching increased CMJ height by 8.1 ± 2.0%, 4 minutes into recovery (2.2 ± 2.0 cm, 95% confidence interval [CI]: 1.0-3.4 cm, p = 0.001), whereas continuous stretching decreased CMJ height by 17.5 ± 3.3% immediately after (-2.9 ± 1.7 cm, 95% CI: -2.0 to -3.7 cm, p = 0.001) and by 12.0 ± 2.7% 1 minute after stretching (-2.2 ± 2.1 cm, 95% CI: -1.2 to -3.2 cm, p = 0.001). The increases in hip (2.9 and 3.6°, p = 0.001. d = 2.4) and knee joint ROM (5.1 and 6.1°, p = 0.001. d = 0.85) after the intermittent and continuous stretching protocols were not different. The opposite effects of intermittent vs. continuous stretching on subsequent CMJ performance suggests that stretching mode is an important variable when examining the acute effects of static stretching on performance in flexibility-trained athletes. © 2018 National Strength and Conditioning Association.

BACKGROUND: Limited research exists examining the effect of different type of plyometric exercises (typical vs. specialized) that are employed as part of warm–up or as a strength–power potentiating complex. Thus, the purpose of this study was to examine the effects of a typical and a specialized plyometric protocol on the occurrence of post–activation potentiation (PAP) effects on drop jump (DJ) performance. METHODS: Thirty–five high level male and female artistic gymnasts participated in this investigation. All participants performed a DJ before and after two different conditioning stimuli; the first consisted of 10 repetitions of a specific gymnastic exercise (Rondat) and the second consisted of 2 set of 5 repetitions of tuc jumps. DJ height, contact time and leg power were assessed before, immediately after and at 3, 6, and 9 min following the conditioning stimulus. RESULTS: DJ height enhanced significantly in post measurements in male and female gymnast (P

Obesity has become one of the major health risks in childhood, significantly affecting children's health and physical fitness. Although the marked increase of obesity in urban areas is well established, evidence is limited in remote and isolated areas with adverse socioeconomic features. The aim of this study was to examine the prevalence of obesity and its association with physical performance indices in young school-aged children living in 18 remote and isolated Greek islands. Methods: Four hundred and sixty-three children (244 boys, 219 girls), aged 5-12 years underwent a series of physical fitness tests including 20 m sprint, standing long jump, 1 kg medicine ball throw, agility T-test and sit-and-reach test. Age and gender BMI cut-off points were determined according to World Health Organisation (WHO) norms. Results: The prevalence of obesity was 23.8% and 13.2% for boys and girls, respectively. A negative body mass index (BMI) main effect was observed for weight-bearing activities, such as 20 m sprint (F=6.21, p=0.000, η =0.041) and standing long jump (F=11.369, p=0.000, η2 =0.074), while medicine ball throw was positively correlated with BMI in children aged 9-12 years. Conclusion: The results of this study confirmed previous findings on obesity prevalence in Greece. A negative association was also found between BMI and physical fitness indices and, in particular, in weight-bearing activities. It is critical to establish physical education interventions and physical fitness programs at schools, aiming to increase motivation for physical activity participation. © 2018, ARHEN - Australian Rural Health Education Network Ltd.

Objective The aim of this study was to compare anthropometric, body composition, and leg power performance in male and female, elite, and national fencers of all age competitive groups and discipline practiced. Subjects and methods A total of 125 fencers (mean ± SD; age 20.6 ± 6.7 years, height 173.2 ± 9.2 cm and body mass 64.7 ± 4.7 kg) participated in this study. Anthropometric measurements were taken before participants performed squat, countermovement, drop, and standing log jump. Results Significant differences were identified between male and female for height (177.6 ± 8.9 cm vs. 167.9 ± 6.2 cm, P 20 years old group for long jump (179.2 ± 30.8 cm vs. 205.2 ± 33.9 cm, P and the 20 years old group for long jump (174.0 ± 30.3 cm vs. 205.2 ± 33.9 cm, P

The consumer attention for products with healthy properties is increased in time, and fruit juices, for their ease of consumption, can satisfy this demand providing them bioactive compounds.The grape juice has numerous health benefits demonstrated by several studies such as, among other, the antioxidant activities and the positive functions of their phenolic compounds. This workis aimed at blending grape and others fruits in a new fruit juice made only with natural ingredients of local production. The grape juice (cv Barbera) has substituted water and its percentagewas fixed (70%). It was mixed with apple (cv Golden delicious), pear (cv Williams) and peach (cv Red Haven) juices to obtain 25 different prototypes. In each of these at least two fruit juices werepresent and added in a percentage variable from 0 to 25%, with a step of 5%. The objectives of this study were to check the feasibility of the mixing process and the evaluation of the samplesoverall pleasantness. Other sensory aspects of samples were also evaluated by consumers with a JAR (just-aboutright) structured scale. The results didn’t reveal particular technological problems regarding the blending process. The Brix mean value of the samples was about 15.3, with a significant reductioncompared to that of the grape juice (about 19). The pH mean value of the samples (3.44) was significantly higher than that of the grape juice (3.36). The titrable acidity and the antioxidant capacitymean value of the samples was, namely, 6.22 g L-1 and 535.18 mg L-1. The penalty analysis of the liking test pointed out the importance of the persistence in mouth. The overall pleasantnesswas significantly (p≤0,01) positively correlated with the °Brix/acid ratio (r=0.54) and samples with the highest percentage of pear juice were generally preferred.

Objective: To explore the participation and attitude of institutionalised elderly towards Physical Activity. The purpose of this study was to evaluate the effects of a plyometric protocol on round kick force and lower limbs’ jumping performance in elite karate athletes and to examine whether this plyometric protocol could be used over repeated trials in competitive warm up conditions. Ten elite level karate athletes (5 males and 5 females) were randomly assigned to an intervention or a control condition of inactivity. The intervention condition consisted of 3 sets of 5 tuck jumps and was repeated over three trials interspersed by ten min of rest. Round kick force, and counter movement jump (CMJ) height, power, relative power, force and rate of force development (RFD) were measured at the beginning and after each trial. The two-way 2x4 repeated measures ANOVA revealed significant condition x time interaction for CMJ height (F= 6.510, p=0.02, η2=0.736). No main effects for time or between conditions were observed, however, CMJ height after the third trial was increased (+3.5%, p

The aim of the present study was to examine the variability of 1-h running performance outside the laboratory, under conditions simulating those of a real competitive event. Twenty-three male recreational runners performed on 3 occasions a 60-min simulated running race attempting to cover as long distance as possible. The races took place in an indoor track, in order to ensure stable environmental conditions. There was no difference in the distance covered between races (12,546.3 ± 217 m, 12,576 ± 219.1 m, 12,638.7 ± 225.3 m for the 1st, 2nd and 3rd races, respectively (mean ± Sx, F2, 44 = 1.168, P = 0.32). The coefficient of variation for all participants was 1.5 ± 0.2 (range: 0.2-3.00). Multiple regression analysis indicated that 83% of the variability in best performance was predicted by determining the speed at the peak volume of oxygen uptake and body mass. In conclusion, performance during 1-h simulated running race in an indoor track was highly reproducible. The present study can be used as low-cost, time-efficient and ecologically valid tool, which could test simultaneously numerous runners’ performance under conditions similar to real competitive events. © 2015 Taylor & Francis.

The aim of this study was to determine the intra-participant variabilities (i.e. intra-day and inter-day reliabilities) in leg and vertical stiffness, as well as related kinematic parameters, during treadmill running using the sine-wave method. Twenty-two healthy men ran on a treadmill at 4.44 m/s, and the flight and contact times were measured with a high-speed video camera. Three 30-s running bouts with 2-min inter-bout rests were performed to examine the intra-day reliability, and single 30-s running bouts on three separate days with 24- to 48-h inter-bout intervals were performed to examine the inter-day reliability. The reliability statistics included repeated-measure analyses of variance, average inter-trial correlations, intra-class correlation coefficients (ICCs), Cronbach's α reliability coefficient, and the coefficient of variation. Both leg and vertical stiffness produced high ICCs within 0.972 and 0.982, respectively, and between 0.922 and 0.873 days, respectively. High values were also observed for all of the reliability coefficients. Similar results were found regarding contact time, flight time, step length, and step rate. It was concluded that the measurements of leg and vertical stiffness, as well as related kinematic parameters, obtained using the sine-wave method during treadmill running at 4.44 m/s, were highly reliable, both within and across days. © 2014 Taylor & Francis.

This study investigated the effects of muscle action type during conditioning activity (half-squat) on subsequent vertical jump performance. Fourteen track and field athletes (relative half-squat of 2.3 ± 0.3 times their body weight) completed 4 main trials in a randomized and counterbalanced order 5-7 days apart: (a) concentric (CON) halfsquats: 7.5 ± 1.2 repetitions against 90% of 1 repetition maximum (1RM), (b) eccentric (ECC) half-squats: 9.3 ± 1.5 repetitions against 70% of 1RM, and (c) 3 sets of 3-second maximal isometric (ISO) half-squats, (d) a control (CTRL) trial, where subjects rested for 10 minutes. The number of repetitions in CON and ECC was adjusted so that the impulse of the vertical ground reaction force was similar to ISO. Countermovement vertical jump (CMJ) performance was evaluated for 21 minutes after each main trial. Countermovement vertical jump performance in ISO was higher than CTRL from the second to the 10th minute of recovery, whereas CMJ performance in ECC was higher than CTRL from the sixth and 10th minute of recovery. Analysis of the peak individual responses revealed an increase in CMJ performance compared with baseline only in ISO (3.06 1.2%; p = 0.045), whereas no significant increases were observed in ECC and CON. Peak CMJ performance for all subjects in ISO and ECC was achieved within 2-10 minutes after the conditioning muscle actions. Isometric were more effective than CON and ECC muscle actions in increasing explosive leg performance when the impulse of the ground reaction force of the conditioning exercise was equated. © 2014 National Strength and Conditioning Association.

This study examined the contribution of instructional self-talk and observational learning on the development of long jump technique. Sixty-nine beginner athletes were randomly assigned to four groups: 'self-talk', 'video', 'self-talk + video' and control group. All groups performed 24 practice sessions, consisting of a cognitive intervention program in the form of either instructional self-talk or observational learning, or a combination of both, and the practice of specific drills. A significantly higher performance improvement was recorded for the self-talk group in post test, whereas when kinematic variables of the motor skill (center of mass displacement) were assessed, "observational learning" proved to be more effective. The findings of the current study suggest that young, beginner athletes, participating in complicated tasks, may benefit from cognitive intervention techniques, through enhanced attentional focus on the most critical elements of the motor skill. © 2013 Human Kinetics, Inc.

The purpose of this study was to examine the acute effect of upper body complex training on power output, as well as to determine the requisite preload intensity and intra-complex recovery interval needed to induce power output increases. Nine amateur-level combat/martial art athletes completed four distinct experimental protocols, which consisted of 5 bench press repetitions at either: 65% of one-repetition maximum (1RM) with a 4 min rest interval; 65% of 1RM with an 8 min rest; 85% of 1RM with a 4 min rest; or 85% of 1RM with an 8 min rest interval, performed on different days. Before (pre-conditioning) and after (post-conditioning) each experimental protocol, three bench press throws at 30% of 1RM were performed. Significant differences in power output pre-post conditioning were observed across all experimental protocols (F=26.489, partial eta2=0.768, p=0.001). Mean power output significantly increased when the preload stimulus of 65% 1RM was matched with 4 min of rest (p=0.001), and when the 85% 1RM preload stimulus was matched with 8 min of rest (p=0.001). Moreover, a statistically significant difference in power output was observed between the four conditioning protocols (F= 21.101, partial eta=0.913, p=0.001). It was concluded that, in complex training, matching a heavy preload stimulus with a longer rest interval, and a lighter preload stimulus with a shorter rest interval is important for athletes wishing to increase their power production before training or competition. © Editorial Committee of Journal of Human Kinetics.

Elite athletes are eager to perform to the best of their ability, regardless of different warm-up stretching techniques used before training or competition which actually help or hinder specific performance variables. The aim of this study was to investigate the acute effects of static or ballistic stretching on flexibility and leg power characteristics of fencing performance in fencers of both genders. Ten male and ten female international level fencers participated in this study. Each subject performed static or ballistic stretching (3 sets of 20 sec) on three muscles of the lower limbs on separate days. Flexibility, squat jump, countermovement jump, drop jump, time and power of lunge and shuttle run test were measured before and after different stretching interventions. Neither static nor ballistic stretching exercises affected flexibility, jumping ability and leg functional fencing performance tests. Moreover, stretching conditions did not affect differently. The results of this study suggest that static or ballistic stretching in the later stages of a general warm-up normally used before training or competition does not hinder specific performance in fencing. Consequently, fencers can continue performing any type of stretching before training or competition at their preference. © 2010, Versita. All rights reserved.

This study investigated selected structural correlates of fencing performance. 33 elite fencers were tested on (a) selected anthropometric, flexibility, and strength-power related parameters, and (b) specific lower extremity functional fencing tests. Multiple regression showed that drop jump and thigh cross-sectional area were best predictors of lunge time and distance of squat jump on the shuttle test. When the two performance variables were expressed per Lean Body Mass, lunge time was significantly predicted only by the performance on the arm-driven counter-movement jump, while time on the shuttle test was best predicted by three noncollinear significant predictors: squat jump performance, thigh circumference, and percent body fat. Lunge time and time on the shuttle test were predicted by explosive power, while none of the nontrainable anthropometric measures or years of training seemed to be important in performance of fencing-related skills. © Perceptual and Motor Skills 2010.

The present study aimed at investigating the differences in selected anthropometric, strength-power parameters and functional characteristics of fencing performance between elite and sub-elite fencers. Thirty-three fencers (18 females and 15 males) from the Greek National Team, (age 19 ± 3.5 yr, body height 175.6 ± 7.6 cm, body mass 66.1 ± 9.1 kg, systematic training 8.4 ± 2.9 yr) were classified as elite and sub-elite, according to their international experience. Subjects underwent a detailed anthropometric assessment and performed selected leg power and fencing-specific tests. Significant differences were observed between the two groups in sitting height, triceps, subscapular, and quadriceps dominant skinfold thickness, absolute and body mass-dependent expressions of leg functional power characteristics of fencing performance: "time of lunge" and time of the "shuttle test". Anthropometric traits, such as height, body mass, percent fat and limb length were not different among elite and sub-elite fencers. Although technical and tactical factors are good indicators of fencing success, the observed differences in functional fencing performance tests among different levels of fencers are useful for the design of effective talent development and training-conditioning programs for competitive fencers. © Editorial Committee of Journal of Human Kinetics.

The relation of leg preference and muscular strength in elite fencers was examined. The dominant and nondominant extensor and flexor muscles of 30 elite fencers (M age = 18.2 yr., SD = 2.0 yr.; M height = 173 cm, SD = 7.4 cm; M weight = 62.7 kg, SD = 8.9 kg), who were members of the Greek national team, and 14 healthy, young, sedentary adults (8 men, 6 women; M age 23.4 yr., SD = 1.9; M height = 169 cm, SD = 10.5 cm; M weight = 66.3 kg, SD = 9.9) were tested for concentric isokinetic contraction at slow (30 to 60°/sec.) and fast (240°/sec.) angular velocities. Significant multivariate differences were found between groups for knee extension, angle of knee extension, knee flexion, and flexor/extensor peak torque ratio. In contrast, no significant difference was found between the dominant and nondominant legs. There was no significant difference in the flexor/extensor peak torque ratio among any of the concentric angular velocities tested. These findings suggest that long-term training in fencing influences the strength characteristics of the lower limbs. © Perceptual and Motor Skills 2009.

In this study the process of peripheral nerve regeneration through an epineural flap conduit was examined using four groups of 126 New Zealand rabbits. There were three study groups (A, B, and C) and 1 control group (D). A 10-mm long sciatic nerve defect was bridged either with 3 variations of an epineural flap (Groups A, B, and C) or with a nerve autograft (Group D). Animals from all groups were examined 21, 42, and 91 days postoperatively to evaluate nerve regeneration employing light microscopy and immunocytochemistry. Nerve regeneration was studied in transverse sections at 3, 6, and 9 mm from the proximal stump. The gastrocnemius muscle contractility was also examined prior to euthanasia at 91 days postsurgery in all groups using electromyography. Immunohistochemical, histochemical and functional evaluation showed the presence of nerve regeneration resembling the control group D, especially in group A, where an advancement epineural flap was used. In this experimental model an epineural flap can be used to bridge a nerve defect successfully. Microsurgery

We investigated hormonal regulators of growth and development, leptin levels, body composition, neuromuscular performance, and the associations among them in trained prepubertal athletes (experimental group [EG]) and an untrained control group (CG). Informed consent was obtained from the children and their parents. Their maturation stage was evaluated according to Tanner's criteria. There were no differences between EG and CG in physical characteristics, body mass index (BMI), lean body mass, testosterone (T), sex hormone-binding globulin, free androgen index, growth hormone (GH), hand grip strength, and jumping performance. Leptin levels and percent fat of the EG were significantly lower than those of the CG (p < 0.05-0.005). Leptin levels were significantly correlated to body fat and BMI for both the EG and the CG (r = 0.51-0.79). There is little evidence that leptin has a positive effect on growth and anabolic factors. Sex hormone-binding globulin and GH may explain the variation of leptin in athletes with low T (R2 = 0.43) and in CG (R2 = 0.35), respectively. Leptin seems to be a permissive factor for the onset of puberty, and the training background needs an optimal biological maturation to produce significant differences in muscle and power performance.

Forty-two untrained prepubertal and pubertal boys formed 2 experimental groups, group STG1 (n = 9; 11-13 years old) and group STG2 (n = 13; 14-16 years old) and 2 control groups (groups CG1 and CG2) of the same age ranges and similar pretraining hormonal levels. Informed consent was obtained from the children and their parents. Groups STG1 and STG2 were submitted to a 2-month resistance training program (6 exercises, 3 × 10 repetition maximum, 3 times a week), followed by a 2-month detraining period. Blood samples were obtained to determine hormonal responses to training and detraining conditions. Their maturation stage was evaluated. Posttraining mean testosterone values of the STG1 and STG2 groups increased by 124 and 32%, respectively (p < 0.001), whereas the free androgen index mean value of the STGl group increased by 74% (p < 0.005). Significant differences in serum testosterone existed between the experimental groups before and at the end of the training period. At the end of the detraining period, the mean hormonal parameters remained practically unaltered. We conclude that strength training stimulates the anabolic and androgenic activities differently in prepubertal and pubertal untrained boys.

Current neurosurgical procedures utilize medical images of various modalities to enable the precise location of tumors and critical brain structures to plan accurate brain tumor resection. The difficulty of using preoperative images during the surgery is caused by the intra-operative deformation of the brain tissue (brain shift), which introduces discrepancies concerning the preoperative configuration. Intra-operative imaging allows tracking such deformations but cannot fully substitute for the quality of the pre-operative data. Dynamic Data Driven Deformable Non-Rigid Registration (D 4 NRR) is a complex and time-consuming image processing operation that allows the dynamic adjustment of the pre-operative image data to account for intra-operative brain shift during the surgery. This paper summarizes the computational aspects of a specific adaptive numerical approximation method and its variations for registering brain MRIs. It outlines its evolution over the last 15 years and identifies new directions for the computational aspects of the technique.