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Background We intended to verify through time-motion analysis the characteristics of the sequences of actions in terms of occurrence during water polo matches: number, duration, and possible relationships with technical-tactical aspects. Methods Water polo matches played at the 18th FINA World Championships 2019 were chosen for examination, and the analysis involved both single actions and Trains of Actions (ToAs). A ToA is a sequence of actions that occurs during the match without actual game interruption. Results A total of 1261 game actions were evaluated in the 17 matches analyzed. In 89% of cases the actions occurred in ToAs while in 11% of cases they took place as single actions. On average, each match included 74.4±5.3 actions; of these, only 7.9±3.4 (C.I. at 95%: lower bound 6.1 and upper bound 9.6) were single actions while 66.2±5.5 occurred in sequences (ToA2 = 29.6 ± 9.0%; ToA3 = 26.1 ± 9.7%; ToA4 = 16.5 ± 10.6%). The winning team performed on average more actions than the losing one (42.1±6.1 vs 32.0±6.4; effect size: 1.67; p value: 0.001). The ToAs had different compositions, from 2 to 18 actions, and then very different durations, from about 1 minute up to 8 minutes. 66% of goals were scored after ToAs and 34% after single actions. Conclusions The study of ToAs provides useful information on the physiological demand of the game, which may help to plan and organize physical training making it as specific as possible. The description of ToAs, can help coaches to better define the game scenario and understand which technical and tactical measures are needed to improve game organization.

In water polo competitions, teams play four periods, each period consisting of eight minutes of actual playing time: a total of 32 minutes (Standard Actual Play Time, SAPT). Substitutions are permitted and a player may be substituted several times. The aim of this article was to provide reference data on played time, taking into consideration the field play position of the players. 352 male water polo players of 18 different nationalities were studied during two consecutive FINA World Championships. 180 games were analyzed and 1980 measurements of the game Measured Actual Play Time (MAPT) were taken. A time density index (DI) was calculated for each athlete using SAPT and MAPT. No statistically significant differences between the field positions were found with regard to age, as was the case in relation to teams between Game MAPT, Tournament MAPT and DI. However, when looking at the diverse field positions (field players, FP; center forward, CF; center back, CB), there were statistically significant differences: Game MAPT FPvsCB p = 0.03 and FPvsCF p = 0.03; Tournament MAPT FPvsCB p = 0.03; DI FPvsCB p = 0.03 and FPvsCF p = 0.04. In these competitions the water polo player had on average a MAPT value of 17.4 ± 6.1 min (54.6 ± 9.5% DI); there were athletes who played 2.3 min (7.1% DI) and others who played up to 31.6 min (95.3% DI). The MAPT in water polo is extremely variable among athletes and must be considered for a correct performance analysis. High-level water polo players require different training strategies depending on their MAPT.

[Purpose] To provide data on the applicability of pedometers in the evaluation of the results of rehabilitative treatment on total daily walking activity after total knee arthroplasty (TKA) and total hip arthroplasty (THA). [Participants and Methods] One hundred fifty six hospitalized patients (age 63.9 ± 12.2 years) involved. On the day of hospitalization and at the end of the rehabilitation treatment the following were performed: clinical examination, X-ray examination and weight. On the same day the pedometer was applied and removed after 48 hours. Only on 30 participants, the same evaluation was carried out 5 days before the hospitalization to measure reliability and responsiveness. Compliance was measured by a face-to-face interview. Visual analogic scale (VAS), Barthel Index (BI) and Ambulation Index (AI) were used to better describe the analyzed sample. [Results] VAS, BI and AI improved by 29.8%, 19.4 and 60.6% respectively. The data obtained on testing-retesting showed a good reliability and a mean Total Error of 7.3% for steps and 15.8% for distance. A good response in the test-retest was detected. The deambulatory autonomy of patients passed from 2,070 ± 740 m to 3,100 ± 810 m. Average improvement in the number of daily steps is 25%. [Conclusion] The data showed a good applicability of pedometer. The results on responsiveness can be used to better interpret the results of rehabilitative treatment on total daily walking activity after THA and TKA.

BACKGROUND: The aim of this work was to compare anthropometric and general physical performance variables in young water polo athletes of three competitive levels, to identify the characteristic qualities and, therefore, the best variables for the identification of talent.METHODS: Fifty-seven young male water polo players between 12 and 14 years old were recruited for the study: 18 were recreational level (REC), 18 sub-elite level (SE) and 21 elite level (EL). To assess anthropometric characteristics the following measurements were used: body mass, height, waist circumference, hip circumference, chest circumference and arm span. Five general performance measures were used: counter movement jump (CMJ), triple hop jump (THJ), push up, chin up and sit up. Relative age was assessed.RESULTS: The whole sample was homogeneous by age (REC 13.1 +/- 0.4, SE 13.2 +/- 1.0, EL 13.3 +/- 0.7 years old) but not in terms of relative age: most of the members of the SE and EL groups were born in the first half of the year. Body mass values (REC 48.2 +/- 11.6, SE 59.3 +/- 11.6, EL 69.1 +/- 4.2 kg) show statistically significant differences between all three competitive levels (REC vs. SE P=0.007, REC vs. EL P=0.001, SE vs. EL P=0.009). As regards the other anthropometric measurements differences were mainly observed between REC and the two other groups: SE and EL had statistically significant higher values in almost all of the measurements carried out. Among the performance measures, lower limb strength (CMJ and THJ) seems to better differentiate between groups: REC group had lower values than the others and EL had the highest values.CONCLUSIONS: Anthropometric characteristics are useful to distinguish the basic level of youth categories from higher competitive levels and should be used for talent selection. The performance results confirm that the subjects' capacity to be trained and sporting practice are essential to reach the elite level.

Physiological effects of different types, of continuous and interval aerobic training, have been largely described and studied in the adult man. It was previously indicated that interval training plays an important role in maximizing both peripheral muscle and central cardiorespiratory adaptations, permitting significant functional improvement even in healthy sedentary subjects. Since the outcome of different aerobic training trials on cognitive processes had never been evaluated, we compared, on an experimental mouse model, the effects of four training exercise protocols, named respectively C100, I100, C50 and I50 depending on the volume and on the type of training proposed, continuous or interval method. Therefore, to asses quantitative and qualitative functional changes, we analyzed several physical parameters before and after 6 weeks training in all four groups with respect to the control sedentary animals and we studied synaptic plasticity, by extracellular in vitro recordings, in hippocampal mouse slices, a region involved in learning and memory processes. We found that all four protocols of exercise applied in this study exerted positive effects on both physical and training parameters inducing weight augmentation, strength endurance and aerobic endurance increase, and potentiation of motor coordination. However, the improvement observed failed to induce an enhancement in synaptic plasticity in three out of four exercise protocols and only in the slices from mice trained with the interval 50% volume exercise the long term potentiation (LTP) increased with respect to the sedentary group. These findings suggest that motor activity exerts positive effects on cognitive processes provided that certain principles are respected, such as the training load and the elements of which it is composed, in order to plan the right quantitative and qualitative parameters and the appropriate recovery periods.

Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports were evaluated during their off-season period. A tetrapolar bioelectrical impedance analyzer was used to determine measurements of resistance (R) and reactance (Xc). The classic BIVA procedure, which corrects bioelectrical values for body height, was applied, and fat-free mass, fat mass, and total body water were estimated. In order to verify the need for specific references, classic bioelectrical values were compared to the reference values for the general male and female populations. Additionally, athletes were divided into three groups: endurance, velocity/power, and team sports. In comparison with the general healthy male and female populations, the mean vectors of the athletes showed a shift to the left on the R&ndash, Xc graph. Considering the same set of modalities, BIVA confidence graphs showed that male and female endurance athletes presented lower body fluids, fat mass, and fat-free mass than other sets of modalities. This study provides BIVA reference values for an athletic population that can be used as a standard for assessing body composition in male and female athletes.

Background: To date, studies on muscle force and power-velocity (F-v and P-v) relationships performed in water are absent. Aim: The goal of this study is to derive the F-v and P-v regression models of water polo players in water vertical thrust performance at increasing load. Methods: After use of a control object for direct linear transformation, displacement over the water and elapsed time was measured, by using a high-speed 2D-videoanalysis system, on 14 players involved in the study. Results: Intra-operator and player’s performance interclass correlation coefficient (ICC) reliability showed an excellent level of reproducibility for all kinematic and dynamic measurements considered in this study with a coefficient of variation (CV) of less than 4.5%. Results of this study have shown that an exponential force-velocity relationship seems to explain better the propulsive force exerted in the water in lifting increasing loads compared to the linear one, while the power and velocity have been shown to follow a second-order polynomial regression model. Conclusion: Given the accuracy of the video analysis, the high reliability and the specificity of the results, it is pointed out that video analysis can be a valid method to determine force-velocity and power-velocity curves in a specific environment to evaluate the neuromuscular profile of each water polo player.

Matrix metalloproteinases (MMPs) exhibit an important function in extracellular matrix degradation. MMPs modulate the activation of growth factors, cytokines and metastasis. At present, the effect of exercise on serum levels of MMP-2 and -9 remains unclear. The aim of the present study was to investigate the effect of various physical activities on the circulating levels of MMP-2 and -9 in breast cancer (BC) survivors and healthy subjects. A total of 66 female subjects were enrolled in the present study. The cohort included 46 BC survivors and 20 healthy subjects divided into 5 groups: Group A (17 BC survivors, participating in recreational dragon boat paddling), group B (14 BC survivors, participating in recreational physical activity), group C (15 sedentary BC survivors), group D (10 healthy subjects, participating in recreational physical activity) and group E (10 sedentary healthy subjects). ELISA assays revealed a significant increase in the level of circulating MMP-2 in group B compared with all other groups. Recreational physical activity increased the levels of MMP-9 in healthy subjects (group D vs. E), however, the differences were not statistically significant, while in the BC survivor groups the results were opposite, with exercise reducing MMP-9 levels (group B vs. C). Furthermore, a significant increase in MMP-2 was observed in group B lymph node metastasis-positive (N+) subjects compared with group A and C N+ subjects. Thus, the results of the present study indicate that various physical activities modulate the levels of circulating MMP-2 and -9 in BC survivors, and the same exercise program induces a different effect when undertaken by healthy subjects and BC survivors. These results may have important implications with regard to the selection of appropriate physical activities for BC survivors, leading to improvements to their survival and prevention of recurrence, as well as amelioration of physical function, quality of life and fatigue.

BACKGROUND The study aims to analyze and quantify the improvements of some physical skills in a group of subjects over 65 years old who practice regular activities in the gym and in a microgravity environment. METHODS The study included 132 subjects (68.9±5.5 years, 72.7±14.4 kg, 155.3±9.2, 30.6±5 kg/m2) who perform regular physical activity adapted and controlled for the elderly twice a week (50' per session) for a period of 8 months. The tests evaluate flexibility, abdominal and leg strength and balance. The groups, in baseline, are homogeneous between them to anthropometric parameters and the initial performance of motor skills analyzed. A mixed between-within subject ANOVA was conducted to assess the impact of the training regimens. Data from this study showed an increase in muscular strength (leg and abdominal muscles), body balance and muscular flexibility after 8 months of both training methods. RESULTS Both experimental groups had significant improvements in motor skills considered and interesting results were observed in water activity, overall, in balance (+66%, P

OBJECTIVE The aim of this study was to evaluate the recovery of muscle strength and measure autonomy 3 yrs after hip replacement surgery in a sample of patients. DESIGN Seventy-eight female patients (70.7 ± 6.3 yrs old) operated on for hip replacement were evaluated. They underwent evaluation tests for hip abductor muscle strength on the healthy and operated limb using strength curves obtained with isometric assessments. Autonomy was evaluated with a rating scale Western Ontario and McMaster Universities Arthritis Index (WOMAC), Harris and MOS 36-Item Short-Form Health Survey (SF-36) and functional assessment (Timed 'Up and Go' test). RESULTS Three years after surgery, a muscle strength deficit was still noticeable on the operated limb compared with the healthy limb ranging from 9% at 5 degrees of adduction to 12% at 0 degree of abduction. The strength curves obtained on the operated side maintained the same descending trend as the healthy side. The authors found no significant correlations between the patient-reported functional measures and the hip abductor strength deficit. The Timed Up and Go test was moderately correlated with the muscle strength deficit. The association between the deficit and the Timed Up and Go test was statistically significant. CONCLUSIONS The evaluation of muscle strength and functional tests are more useful than the rating scales in patients 3 yrs after surgery. The strength curves are useful to have different levels of information and describe joint function.

Elite water polo athletes undergo heavy training programs throughout the year, but especially to prepare major competitions, such as the Olympic Games (OG). Optimal athletic performance is a result of many factors, including proper management of the intensity and volume of training, nutrition and recovery between training sessions. When training is excessive in relation to recovery may occur nonfunctional overreaching (NFO). NFO can degenerate into overtraining syndrome resulting in a decrease in athletic performance, with likely changes in body weight and body composition. The aim of this study was to evaluate the relationship between body composition and the tolerance to intense training supported by diet meal plans and to highlight any difference between athletes selected for the OG and not selected ones.Twenty-one male elite water polo athletes, 26 to 34 years of age, participated in the study. For three months before the Olympics, athletes have carried out an intense training period based on a detailed program. Only 13 athletes participated to OG (OA), 8 were excluded (NOA). Body weight and height were measured and Body Mass Index was calculated. BC and phase angle was evaluated at the half of first (T0), second (T1), and third (T2) month of training. Also blood analyses were collected at T0 and food intake assessed in all the evaluations. Measurements were carried out at three selected time points throughout the training period (12 weeks), which marked variations in the volume and intensity of the training load.Data analyses showed no statistical difference among the three measurements performed for body weight, body composition and phase angle in all OA group. Furthermore, there was not statistically significant differences between the OA and NOA group for weight, body mass index, body composition and phase angle.Results of the present study encourage the use of body composition by bioelectrical impedance monitoring system for high-level athletes involved in long and intense training periods to prevent body dehydration and overtraining syndrome. Body cell mass monitoring provides a valuable help to evaluate the effects of training and to prevent any decrease in the performance level.

BACKGROUND The aim of this work was to study anthropometric and performance measurements in 60 young male volleyball players (YV) and 60 youth not active in the sport (YNA) to assess which of these would be more useful to study the characteristics of potential performers. METHODS Eight measures to assess anthropometric characteristics, six performance measures and two tests for joint mobility were used. Also relative age and level of maturation were assessed. RESULTS The anthropometric variables, relative age and level of maturation measured did not show statistically significant differences between groups. The YV and YNA groups showed differences in the performance measures. YV group was characterized by a better performance of the ability to repeat short sprints, of the upper limbs, abdominal muscles and lower limbs, with a medium effect size (Shuttle Running Test: 0.6; Push-Up: 0.5; Sit-Up: 0.4; counter movement jump: 0.4). These performance variables were very sensitive and specific: the SRT measurement had the best positive likelihood ratio that indicates the utility of the test in identifying type of players (YV and YNA). CONCLUSIONS In talent detection in youth volleyball, in the 11-13 age range, performance variables should be preferred to anthropometric ones.

BACKGROUND This study investigated the applicability of a sport-specific test, the Shuttle Swim Test, in young water polo players to measure RSA. The aims were: to assess the reliability and to measure the responsiveness of the SST in young water polo athletes, and to provide age-related values of SST. METHODS Three hundred thirty-three elite athletes (18.3±5.1 years) were involved in the study. Of these, 99 were young people under 13 (13.1±0.5 years) who also underwent measurements for reliability and responsiveness of the SST The following six measures was used to assess anthropometric characteristics of the sample: height, weight, chest circumference, hip circumference, waist circumference, and arm span. Two performance measures were performed on dry land: push up and chin up. RESULTS Reliability and responsiveness were measured by comparing the average speed of two trials: SST1 was 1.48±0.13 m·s-1 and SST2 1.47±.12 m·s-1. The SST showed good reliability in younger athletes (r=0.96). The Minimal Detectable Change is 0.06 m·s-1 (6 seconds of the total time) which corresponds to 3.6% of the average value measured, confirming the good responsiveness of the test. CONCLUSIONS Coaches and researchers can use this value in the interpretation of the SST test results: changes below these values could be related to a measurement error. The various age-related values reported may help technicians to better interpret the performance of their athletes during competition.

The aim of this study was to determine whether the rate of change of surface EMG variables during a constant force isometric fatiguing contraction (80% MVC, 30 s of duration) of vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles is able to distinguish between nine sprinters and nine long distance runners. Signals were recorded with linear arrays of eight electrodes. Muscle fiber conduction velocity (CV), mean frequency (MNF) of EMG signal power spectrum and average rectified value (ARV) of the EMG signal were calculated both from the whole signal (global approach) and from motor unit action potentials (MUAP distribution approach) extracted from the signal. Results showed significant differences only in the MUAP distribution approach. For this approach, the rates of change of conduction velocity (CV) (both absolute and normalized with respect to the initial value) were found to be always greater in the sprinter (VMO: -0.012 +/- 0.011 m s(-2) and -0.25 +/- 0.21%/s; VL: -0.014 +/- 0.009 m s(-2) and -0.27 +/- 0.17%/s) than in the long distance runner group (VMO: -0.004 +/- 0.006 m s(-2) and -0.08 +/- 0.14%/s; VL: 0.003 +/- 0.012 m s(-2) and 0.08 +/- 0.26%/s) (VL: p = 0.016, VMO: p = 0.034). No differences were observed in the CV initial values and in rates of change of MNF, while MNF initial values recorded from the VMO were found to be greater (119.6 +/- 25.1 Hz) in the sprinter group than in the long distance runner group (99.2 +/- 12.1 Hz, p = 0.016). A correlation was found between initial values and rates of change of CV in the VMO (r = 0.61, p0.01, N = 18, Spearman correlation coefficient). The consistency of these findings with the expected fiber type composition between sprinters and long distance runners and the identification of a set of candidated variables for the assessment of muscle adaptation during training and/or rehabilitation programs represent the main results of the study.

In water polo, many of the technical actions and the contacts with the opponent take place in quasi-vertical floating position using 2 types of lower limb actions: the eggbeater kick is used most often in fighting and passing and the breaststroke kick in jumping and throwing. The aim of this study was to identify a new system to evaluate and to train the eggbeater kick movement and to verify its applicability. Twenty amateur players and 22 elite players participated in the study. A jacket, homemade and easy to make, allowing the application of an overload submerged in water but not hindering breathing or mobility, was used. Standard anthropometry and a test consisting of different trials of the eggbeater kick action until exhaustion with an increasing overload (5, 7.5, 10, 12.5, 15, and 17.5 kg) were collected. Time to exhaustion and the overload estimated maximum value (OEMV) at second 2 were determined for each load. Body weight, height, and lower limb muscle performance of the elite and nonelite players were significantly different from each other (p ≤ 0.05). The effectiveness of the different measured variables in both subgroups and that of the OEMV was evaluated with receiver operating characteristic (ROC) curve analysis. Areas under the ROC curve for the different overloads were 0.72 (0.53-0.92) for 5 kg, 0.80 (0.68-0.90) for 7.5 kg, 0.87 (0.77-0.91) for 10 kg, and 0.88 (0.84-0.92) for 12.5 kg overload. Our results show that the test is sensitive enough and therefore can be used to plan and control training and injury recovery.

The aim of the present article was to assess the reliability of strength curves as determined from tridimensional linear accelerations and angular velocities measured by a single inertial measurement unit (IMU) fixed on the upper arm during a shoulder abduction movement performed holding a 1 kg dumbbell in the hand. Within-subject repeatability of the task was assessed on 45 subjects performing four trials consisting of one maximal shoulder abduction-adduction movement. Intraclass correlation coefficient (ICC) was computed on the average movement angular velocity (VEL) and range of movement (ROM) across the four trials. Within-subject repeatability of torque curves was assessed in terms of waveform similarities by computing the coefficient of multiple determination (CMD). Accuracy of the estimated ROM was assessed using an isokinetic dynamometer. High ICC values of ROM (0.955) and VEL (0.970) indicated a high within-subject repeatability of the task. A high waveform similarity of torque curves was also found between trials (CMD = 0.867). Accuracy with respect to isokinetic dynamometer in estimating ROM was always

Three series of novel tensile and flexural creep tests on partially-damaged concrete specimens were carried out in order to gain some insight into creep crack growth and failure of strain-softening materials. In the tests, each specimen was initially loaded to a given point in the descending branch and thus had a lower load-carrying capacity than that at the peak-point. Then, the specimen was unloaded and reloaded to sustain a load which was from 70% to 95% of its current load-carrying capacity. Experimental creep curves display a three-stage process, consisting of primary, secondary and tertiary stages, with a decreasing, constant and increasing creep rate, respectively. The secondary stage dominates the whole failure lifetime, whereas both the secondary and tertiary stages are important in terms of creep deformation. Failure life-time seems to be more sensitive to the change of load level in flexural tests rather than in tensile tests. The decrease in load-carrying capacity due to damage tends to result in a shorter failure lifetime and a lower critical load level for creep rupture. The descending branch of the static load-deflection or load-CMOD curve may be used as an envelope criterion for creep fracture.

Fencing is a sport practiced by both men and women, which uses 3 weapons: foil, epee, and saber. In general, there are few scientific studies available in international literature; they are limited to the performance analysis of fencing bouts, yet there is nothing about saber. There are 2 kinds of competitions in the World Cup for both men and women: the "FIE GP" and "A." The aim of this study was to carry out a saber performance analysis to gain useful indicators for the definition of a performance model. In addition, it is expected to verify if it could be influenced by the type of competition and if there are differences between men and women. Sixty bouts: 33 FIE GP and 27 "A" competitions (35 men's and 25 women's saber bouts) were analyzed. The results indicated that most actions are offensive (55% for men and 49% for women); the central area of the piste is mostly used (72% for men and 67% for women); the effective fighting time is 13.6% for men and 17.1% for women, and the ratio between the action and break times is 1:6.5 for men and 1:5.1 for women. A lunge is carried out every 23.9 seconds by men and every 20 seconds by women, and a direction change is carried out every 65.3 seconds by men and every 59.7 seconds by women. The data confirm the differences between the saber and the other 2 weapons. There is no significant difference between the data of the 2 different kinds of competitions.

Elastic tubes are devices relatively inexpensive, easy to use, portable and safe, which are claimed to provide advantages with respect to training with free weights or weight machine. The aim of this work was to assess neuromuscular modification induced by the use of two different muscle contraction modalities (elastic versus weight resistances) until exhaustion. Fourteen healthy physically active male students (age: 28±6 years; body mass 72.1±11.0kg; height: 173.5±6.9cm) were recruited. They were requested to reach exhaustion with dynamic contraction at 70% of their own One Repetition Maximal (1RM) using, in two different days and in random order, Thera Band® tubes or traditional weight plates on an arm machine designed and built for those tasks. Before and after such contractions a standardized fatiguing isometric test (3 Maximal Voluntary Contractions, MVC plus 60s at 60% MVC) was requested to assess differences induced by the exhaustion sessions. During fatiguing tests surface EMG signals were recorded from biceps brachii muscle with linear arrays of eight electrodes (silver bars 10mm apart, 5mm long, and 1mm diameter) in single differential configuration. Initial values and rates of change of Average Rectified Value (ARV), MeaN power Frequency (MNF) and muscle fiber Conduction Velocity (CV) were calculated to compare the effects of the two contraction modalities. No differences were found between "elastic session" and "weight session" PRE MVCs (31.9±8.8 and 29.9±8.3nm, respectively) and endurance times (28±6 and 26±7s, respectively). The same was observed for POST values. During the post-contraction isometric fatigue test, the only parameters influenced by the contraction modality were the initial CV and the rate of change in CV which were 12% and 37% greater (p

An experimental and numerical investigation is carried out for a particular testing geometry: a single-edge notched specimen subjected to four-point shear, where a mixed-mode crack propagation is activated in concrete, if the specimen is not too small and the aggregates are not too large. When both conditions are verified each crack growth step is governed locally by a mode I strain field and the energy dissipation is tendentially provided by the fracture energy G F , whereas permanent deformation in the bulk material and interlocking on the crack surface are negligible.

Loss of dopamine neurons in experimental parkinsonism results in altered cyclic nucleotide cAMP and cGMP levels throughout the basal ganglia. Our objective was to examine whether expression of phosphodiesterase 10A (PDE10A), an isozyme presenting a unique distribution in basal ganglia, is altered after unilateral injection of 6-hydroxydopamine in the medial forebrain bundle, eliminating all midbrain dopaminergic neurons, such that cyclic nucleotide catabolism and steady state could be affected. Our study demonstrates that PDE10A mRNA levels were decreased in striatal neurons 10 weeks after 6-hydroxydopamine midbrain lesion. Such changes occurred in the striatum ipsilateral to lesion and were paralleled by decreased PDE10A protein levels and activity in striatal neurons and in striato-pallidal and striato-nigral projections. However, PDE10A protein and activity were increased while PDE10A mRNA was unchanged in the nucleus accumbens ipsilateral to the 6-hydroxydopamine midbrain lesion. Accordingly, cAMP levels were down-regulated in the nucleus accumbens, and up-regulated in the striatum ipsilateral to the lesion, but they were not significantly changed in substantia nigra and globus pallidus. Unlike cAMP, cGMP levels were decreased in all dopamine-deafferented regions. The opposite variations of cAMP steady state in striatum and nucleus accumbens are concordant and likely dependent, at least in part, on the down-regulation of PDE10A expression and activity in the former and its up-regulation in the latter. On the other hand, the down-regulation of cGMP steady state in the striato-nigral and striato-pallidal complex is not consistent with and is likely independent from the concomitant down-regulation of PDE10A. Therefore, dopamine loss inversely regulates PDE10A gene expression in the striatum and PDE10A post-transcription in the nucleus accumbens, therein differentially modulating PDE10A-dependent cAMP catabolism.

The purpose of this study was to examine game demands during highly competitive men's water-polo games after the introduction of the new Federation International Natation Association (FINA) rules. Participants of this study were 77 outfield international level men's water-polo players (age 25.9 ± 4.5 years, height 188 ± 4.5 cm, body mass 93 ± 10.9 kg). Game earlobe blood lactate, speed, and distance covered (semiautomatic image recognition system) were measured during 6 highly competitive matches (FINA International Tournament). In the game, players covered 1,613 ± 150 m (n = 68). This corresponds to a mean coverage rate of 54 ± 5.8 m·min (n = 68). At speeds faster than 1.4 m·s⁻¹ (high-intensity swimming), players covered 44% of the total distance. A significant decrease in coverage rate was detected during the final stage of the game. Mean blood-lactate concentration was 7.7 ± 1.0 mmol·L⁻¹ (range 2.2-14.3). Center Defenders (1,816 ± 496 m) covered significantly (p < 0.05) more distance swimming compared to Field (1,676 ± 348 m) and Center-Forward (1,317 ± 281 m) players. Mean match blood-lactate concentrations for Center Forwards, Center Defenders, and Field Players were 11.2 ± 1.0 (3-14.3), 6.7 ± 0.9 (1.4-8), and 5.3 ± 0.9 mmol·L⁻¹ (2.2-11.9), respectively. This study confirmed the high-intensity nature of male elite level water polo showing remarkable role-dependent game demands. As a result, strength and conditioning interventions should be individualized and mainly address intermittent high-intensity endurance and anaerobic fitness.

Manganese (Mn) is a cofactor for some metalloprotein enzymes, including Mn-superoxide dismutase (Mn-SOD), a mitochondrial enzyme predominantly localized in neurons, and glutamine synthetase (GS), which is selectively expressed in astroglial cells. The detoxifying effects of GS and Mn-SOD in the brain, involve catabolizing glutamate and scavenging superoxide anions, respectively. Mn intoxication is characterized by impaired function of the basal ganglia. However, it is unclear whether regional central nervous system expression of manganoproteins is also affected. Here, we use immunocytochemistry in the adult rat brain, to examine whether Mn overload selectively affects the expression of GS, Mn-SOD, Cu/Zn-SOD, another component of the SOD family, and glial fibrillary acid protein (GFAP), a specific marker of astrocytes. After chronic Mn overload in drinking water for 13 weeks, we found that the number and immunostaining intensity of GS- and Mn-SOD-positive cells was significantly decreased in the striatum and globus pallidus, but not in the cerebral frontal cortex. In addition, we found that GS enzymatic activity was decreased in the strio-pallidal regions but not in the cerebral cortex of Mn-treated animals. In contrast, Cu/Zn-SOD- and GFAP-immunoreactivity was unchanged in both the cerebral cortex and basal ganglia of Mn-treated rats. Thus, we conclude that in response to chronic Mn overload, a down-regulation of some manganoproteins occurs in neurons and astrocytes of the striatum and globus pallidus, probably reflecting the vulnerability of these regions to Mn toxicity.

The objective of this study was to verify the impact of various sports on body cell mass (BCM). Ninety-eight male subjects, 17-33 years of age, participated in the study. The sample included athletes from three professional Italian football (soccer) teams, representing three different divisions (A, n=16; B, n=14; and C, n=18), judo athletes (J, n=10), and water polo athletes (W, n=14) who all competed at the national level. Twenty-six age-matched individuals served as the control group (CG). Fat-free mass (FFM), fat mass (FM), percent body fat (%BF), and BCM were assessed using bioimpedance spectroscopy (BIS). There were no significant differences in body weight and FFM among the groups. A and B were significantly taller than J and CG. B had a significantly lower body mass index (BMI; kg/m(2)) than CG, while C had a significantly lower BMI than J and CG. CG had a significantly greater FM and %BF than A, B, and C. C had a significantly lower BCM than Aand B. CG had a significantly lower BCM than A, B, J, and W. In conclusion, differences in BCM exist among athletes of different sports, and among athletes within the same sport who compete at different levels.

Background: Several studies have evaluated the accuracy of portable metabolic gas analysis systems, which measure physical activity energy expenditure. Since the Cosmed K2 telemetric system, two K4 devices (RQ and b2) have been developed. Objective: To compare measurements using the Cosmed K4 RQ with measurements by a traditional method (mass spectrometer) for a sample of healthy subjects performing physical exercise of various intensities. Methods: Nine healthy male footballers (mean (SD) age 18.3 (2.2) years) performed an incremental exercise running test from 8 km/h to exhaustion, with an increase of 2 km/h for each level of the test protocol. The expired air was collected simultaneously using the Cosmed K4 RQ and Airspec QP9000 mass spectrometer. Oxygen consumption (Vo 2 ) and carbon dioxide production (Vco 2 ) were measured at rest and at each exercise intensity. Results: No significant differences were found between Vo 2 and Vco 2 measured by the two instruments, at rest or during exercise. Conclusions: The application of the Cosmed K4 RQ system for Vo 2 and Vco 2 measurements at rest and during both submaximal and maximal exercise may be of interest to sport physiologists, nutritionists, and doctors.

Purpose: The aim of this work is to provide information about the degree of inter-subject uniformity of location of innervation zone (IZ) in 13 superficial muscles of the lower limb. The availability of such information will allow researchers to standardize and optimize their electrode positioning procedure and to obtain accurate and repeatable estimates of surface electromyography (sEMG) signal amplitude, spectral variables and muscle fiber conduction velocity. Methods: Surface EMG signals from gluteus maximus, gluteus medius, tensor faciae latae, biceps femoris, semitendinosus, vastus medialis obliquus, vastus lateralis, rectus femoris, tibialis anterior, peroneus longus, soleus, gastrocnemius medialis and lateralis muscles of ten healthy male subjects aged between 25 and 34 years (average=29.2 years, S.D.=2.5 years) were recorded to assess individual IZ location and signal quality. Results: Tensor faciae latae, biceps femoris, semitendinosus, vastus lateralis, gastrocnemius medialis and lateralis showed a high level of both signal quality and IZ location uniformity. In contrast, rectus femoris, gluteus medius and peroneus longus were found to show poor results for both indexes. Gluteus maximus, vastus medialis obliquus and tibialis anterior were found to show high signal quality but low IZ location uniformity. Finally, soleus muscle was found to show low signal quality but high IZ location uniformity. Conclusions: This study identifies optimal electrode sites for muscles in the lower extremity by providing a standard landmarking technique for the localization of the IZ of each muscle so that surface EMG electrodes can be properly positioned between the IZ and a tendon.