Showing papers in "Journal of Sports Medicine and Physical Fitness in 2007"

Selection of young soccer players in terms of anthropometric and physiological factors.

Abstract: Aim The aim of this paper was to describe the anthropometric and physiological characteristics of young soccer players (14-17 years old) which were associated with their being successful or not as soccer players. Methods Somatotype and body composition was calculated by measuring skinfolds, limb circumferences and joint diameters. VO(2max) was estimated by the Astrand's Test. Sprint, jump and endurance tests were also performed. Results The most relevant differences were obtained between selected and non-selected players belonging to the 14-year-old team. Selected players were taller, heavier, leaner and faster and they had higher absolute or relative VO(2max). In addition, a higher % of selected players was found among those born during the first 6 months of the year. In the rest of the teams, the agility was better in selected than in non-selected players. At later ages, there was also a predominance of players born during the first 6 months of the year. Conclusions These results indicate that around the time of puberty, parameters associated with physical maturity such as height, size, speed, VO(2max), or chronological age are important to determine the success of a soccer player. At older ages, other factors such as agility seem to be more important. Nevertheless, players born in the 1st semester of the year are also more frequent in the older teams. These findings should be taken into account by trainers and coaches, in order to avoid biasing their selection choices.

Measuring self-determination motivation in a physical fitness setting: validation of the Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2) in a Spanish sample.

Abstract: Aim The aim of this study is the validation in the Spanish context of the Behavioural Regulation in Exercise Questionnaire-2 (BREQ-2) scale, developed by Markland et al., from the point of view of the self-determination theory and to compare the effect of gender, age and exercise duration and mode. Methods For the validation of the instrument, two studies were carried out (n=250 and n=311) with a total sample formed of 561 adults in the metropolitan area of the city of Murcia, Spain, who do non-competitive sport and physical activities. They were given the adaptation of the questionnaire BREQ-2 by Markland et al. to fill in. Results After an exploratory factor analysis and a confirmatory factor analysis, an adaptation of the scale was obtained with 18 items and 5 factors with acceptable reliability coefficients and a total variance explained of 68.8%. The two highest assessed forms of behavioral regulation were intrinsic and identified, with the women showing more intrinsic regulation. Those that exercised for less time were the ones that showed higher levels of amotivation and the older people showed a greater tendency to identified regulation. Conclusion The BREQ-2 scale has all the required conditions, as far as reliability and validity criteria are concerned, to be used in the Spanish context in different areas of physical activity.

Factors associated with anterior cruciate ligament injury: history in female athletes.

Abstract: AIM: Little is known about the association of lower extremity structural malalignments, flexibility patterns, generalized laxity, postural control, previous ankle sprain history and the increased risk of anterior cruciate ligament (ACL) injuries in females We hypothesized that females with a history of ACL injury would be more likely to have a history of prior ankle sprain and different structural alignments than females without a history of ACL injury METHODS: It is a case control study: 33 young adult females with a history of an ACL injury and 33 controls with no history of knee injury provided their knee and ankle injury history and had 16 lower extremity measures taken RESULTS: The factors most associated with ACL injury history were greater generalized laxity (r(2) change: 0073), greater genu recurvatum (r(2) change: 0069), and decreased iliotibial band (ITB) flexibility (r(2) change: 0069) There was also a significant association between ACL injury history and previous ankle sprain injury history (chi squared=527; P=002) Those with a history of ACL injury were more likely to have had a prior ipsilateral ankle sprain CONCLUSION: Increased generalized laxity, greater genu recurvatum, and decreased ITB flexibility discriminated between females with and without history of ACL injury A relationship linking previous ankle injury and ACL injury risk was found Taking a thorough medical history and screening for generalized laxity, genu recurvatum, and a tight ITB in those with a history of LAS, may help identify those at risk for an ACL injury and who may benefit most from preventive measures Language: en

Relationship between measured maximal oxygen uptake and aerobic endurance performance with running repeated sprint ability in young elite soccer players.

Abstract: Aim The aim of the study was to determine the relationships between maximal oxygen uptake (VO(2max)) in a maximal treadmill run and the aerobic endurance performance in the 20-m multistage shuttle run (MST) test, with the performance indices obtained in the running repeated sprint ability (rRSA) test, in elite youth soccer players. Methods Thirty-seven adolescent male outfield players performed on separate days and in random order the treadmill run test and the MST, to obtain their measured VO(2max) and aerobic endurance performance (via the number of completed shuttles in the MST), respectively. Players also completed the rRSA test of 6x20-m all-out sprints, interspersed with 20 s of active recovery. Results There was a significant moderate correlation between measured VO(2max) (in L . min(-1) and mL . kg(-1) . min(-1)) and MST results (r=0.43 and 0.54, P 0.05). Conclusion The moderate association between the measured VO(2max) and MST suggests that both tests were plausibly measuring different aspects of a player's aerobic fitness. The lack of association between measured VO(2max) and aerobic endurance performance in the MST with performance in the rRSA suggests that aerobic fitness per se is poorly associated with performance in the rRSA in elite youth soccer players.

Changes in heart rate and blood lactate concentration as intensity parameters during simulated Taekwondo competition.

Abstract: Aim. The absence of studies related to physiological responses in athletes during Taekwondo competition makes this the first attempt to investigate the physical aspects of this relative new Olympic sport event. Therefore, the aim of this study was to record and analyze heart rate (HR) and blood lactate (BL) levels of elite male Taekwondo athletes during multiple competition bouts in a single day. Methods. Experimental design: prospective. Setting: competition simulation. Participants: 24 elite male athletes, aged 20 to 24 years. Measures: HR and BL responses were studied on 24 national level Taekwondo players in multiple competition bouts to explore the aerobic-anaerobic metabolism, as well as the physical demands of the players. The aerobic capacity (VO 2max ) of the players were determined using a 20 m shuttle run test. HR and BL concentration levels were measured during warm up and fighting rounds in every competition bout. Results. The mean VO 2max ability for all subjects was 53.92 mL/kg/min and there was no significant difference between groups. Only the heavy weight division (+80 kg) players demonstrated a significant higher HRmax (P<0.05) than the other two divisions. No inter-weight division, as well as inter-round differences, were observed in the HR and BL concentration levels of the players. After all divisions were recorded and analyzed the mean HR and BL levels during competition were 158 beats/min and 3.35 mmol/L, respectively. Conclusion. The study highlights that in competitive Taekwondo, irrespective of the weight division or aerobic capacity, the anaerobic adaptability of the subjects is the same.

Bilateral pedaling asymmetry during a simulated 40-km cycling time-trial.

Abstract: Aim. This study investigated the pedaling asymmetry during a 40-km cycling time-trial (TT). Methods. Six sub-elite competitive male cyclists pedaled a SRM® Training Systems cycle ergometer throughout a simulated 40-km TT. A SRM® scientific crank dynamometer was used to measure the bilateral crank torque (N.m) and pedaling cadence (rpm). All data were analyzed into 4 stages with equal length obtained according to total time. Comparisons between each stage of the 40-km TT were made by an analysis of variance (ANOVA). Dominant (DO) and non-dominant (ND) crank peak torque asymmetry was determined by the equation: asymmetry index (AI%)=[(DO-ND)/DO] 100. Pearson correlation analysis was performed to verify the relationship between exercise intensity, mean and crank peak torque. Results. The crank peak torque was significantly (P<0.05) greater in the 4 th stage compared with other stages. During the stages 2 and 3, was observed the AI% of 13.51% and 17.28%, respectively. Exercise intensity (%VO 2max ) was greater for stage 4 (P<0.05) and was highly correlated with mean and crank peak torque (r=0.97 and r=0.92, respectively) for each stage. Conclusion. The DO limb was always responsible for the larger crank peak torque. It was concluded that pedaling asymmetry is present during a simulated 40-km TT and an increase on crank torque output and exercise intensity elicits a reduction in pedaling asymmetry.

Evolution of physiological and haematological parameters with training load in elite male road cyclists: a longitudinal study.

Abstract: Aim The aim of this study was to describe and evaluate physiological parameters as a control tool for the monitoring of training in a group of elite cyclists during one season of training. Methods The study is divided into two periods (winter or ''volume'' mesocycle and spring or ''intensity'' mesocycle) between the tests that they carried out in the laboratory, consisting of a ramp test to exhaustion (work load increases 25 W X min(-1)) and a maximal lactate steady state (MLSS) test on a cycle ergometer. Macronutrients and hematological variables were recorded during the test periods as were the volume and the intensity of training sessions during the whole period of the study. Results The physiological data were similar to those previously reported for professional cyclists (approximately 450 Watts, approximately 78 mL x kg(-1) x min(-1)) and the values for the MLSS also agree with previous studies (approximately 250 Watts). Subjects improved the first ventilatory threshold (VT(1)) (approximately 52% to approximately 60% VO(2max)) and the second ventilatory threshold (VT(2)) (approximately 82% to approximately 87% VO(2max)) after the first period of training even though its low intensity focused on the performance of VT(1) (77% training in ''zone 1'', under VT(1)). The MLSS improved after the first period (approximately 225 to approximately 250 Watts) and remained high in the second (approximately 255 Watts). High levels of creatine kinase (approximately 230 U x L(-1)) and urea (37 mg x L(-1)) were found, also a decrease in hemoglobin values (approximately 15.4 to approximately 14.7g x dL(-1)). Conclusion The high level reached by the subjects after the first period of training suggests that two effort tests could be enough to plan training. On the other hand, the decrease in some red blood cell and nutrition parameters suggests that there should be greater control over them during the season.

Poor relationship between strength and power qualities and agility performance.

Abstract: AIM: Despite the important role of agility in successful performance in many team and racket sports, little is known about their physiological and muscular basis. The aim of this study was to examine the relationship between the leg extensor strength and power and agility performance. METHODS: Male physical education students (n=76) were assessed by means of 3 typical agility performance tests (lateral stepping, 20-yard shuttle run, and slalom run). Six tests of leg extensor strength (isoinertial squat, isometric squat, and one-leg rising) and power (squat jump power, hopping power, and standing long jump distance) were also obtained. RESULTS: The correlations between strength and power, and each agility performance were generally low. As a consequence, the multiple correlation coefficients between strength and power predictors and agility, albeit significant (P<0.01), were also rather low (r=0.33, 0.44, and 0.35 for the lateral stepping, 20-yard shuttle run, and slalom run, respectively). The highest relationship with each of the agility tests was revealed by the one-leg rising test (r within -0.3 and -0.44 ; P<0.02). CONCLUSION: The results of the present study suggest that most of the multijoint leg extensor strength and power measures are poor predictors of agility in physically active men. Thus, the effects of interventions aimed towards the improvement of functional movement performance may not require evaluation by means of the common tests of muscular strength and power. A more specific approach including both the functional strength tests and functional movement performance tests could be recommended instead.

Jumper's knee treatment with extracorporeal shock wave therapy: a long-term follow-up observational study.

Abstract: Aim. Jumper’s knee affects more frequently athletes participating in jumping activities. This pathology is very difficult to treat: various therapeutic treatments are used, often based on the physician’s personal experience rather than clinical evidence. The aim of this prospective study is to present our experience with the treatment of jumper’s knee using extracorporeal shock wave therapy (ESWT) in a group of patients followed up for 2 years after treatment. Methods. In this study, we included 73 sports patients (83 knees), 54 males and 19 females, aged between 15 and 69 years (mean age: 32 years). All patients underwent clinical and instrumental diagnosis (ultrasonography, magnetic resonance imaging and X-rays) in order to identify presence, location and seriousness of the specific tendinopathy. The symptomatology was classified using the visual analogical scale and according to a 6stage clinical evaluation range. Shock wave treatment was applied with an electromagnetic shock wave generator. The protocol consisted in an average of 4 sessions (minimum 3, maximum 5), at a 2/7-day interval. In each sessions, 1 500-2 500 impulses were administered with an energy varying between 0.08 and 0.44 mJ/mm 2. Results. We obtained satisfactory results in 73.5% of cases (54.2% excellent results and 19.3 good results). In performing athletes (16 tendons), treatment was satisfactory in 87.5% of cases, with an average time of resuming sport of approximately 6 weeks. Conclusion. The outcome of the described shock wave treatment appears to be satisfactory and confirms the role of this alternative treatment in the management of the tendon disorders. K EY WORDS: Short-wave therapy - Tendinopathy - Patellar ligament - Knee - Physical therapy modalities.

Martial arts as sport and therapy.

Abstract: The term Martial Arts is often used as general phrase to describe many of the combat arts, which have developed in eastern cultures over the past millennium. This paper reviews the Martial Arts from the original context of a trio of life skills. This trio includes the healing arts such as acupuncture, the self-exploration arts such as yoga, and the vital life skills such as meditation. As Martial Arts suggests the waging of combat, the origins of the most common combat arts are reviewed, with an overview of the difference between the hard and the soft styles. The arts developed not only in the eastern, but also in all parts of the world, with references of these types of combats arts in the writings of the ancient Egyptians and Greeks. In modern times, the combat arts are performed for both exercise and sport. A review of the injuries that occur, and the health benefits that might be expected are discussed. A review of the medical literature that demonstrates some of these health benefits is included, with Tai Chi Chuan as the most studied of these. The health benefits discussed include strengthen and self-efficacy of the elderly, reduced falls, increased exercise capacity, and benefits to the immune system and autonomic nervous system. The paper emphasized the breadth of the Martial Arts and the import of these to the sports and health community.

Finger pain in rock climbers: reaching the right differential diagnosis and therapy.

Abstract: Injuries and overuse syndromes of the fingers are the most common problems in rock climbers While injuries to the finger flexor pulley system and tenosynovitis are well known to be frequent problems, other syndromes like the lumbrical shift syndrome or flexor tendon ganglions are rather unknown The differential diagnosis of finger pain in rock climbers involves many differential diagnoses and can be quite difficult The diagnostic and therapeutic procedures for the evaluation of finger pain in rock climbers are demonstrated More than 20 different diagnoses need to be considered After taking a thorough history, clinical examination and radiography the ultrasound is the most helpful diagnostic aid Being a cheap and harmless examination it provides plenty of information for further differential diagnosis A linear array transducer with 10-12 MHz in a prone position performing longitudinal and transversal planes is mostly used Only occasionally an additional MRI is necessary The physiologic adaptations due to the high impact of rock climbing onto the fingers need to be strictly separated from pathologic change The rising number of epiphyseal fractures in young climbers must be observed critically and information needs to be given out to parents, trainers and the athletes themselves The question of the influence of high intensive climbing and training in young age and a possible higher risk for osteoarthrosis of the finger joints needs to be further explored

Throwing effectiveness and rotational strength of the shoulder in team handball.

Abstract: Aim The purpose of this study was to examine: a) the influence of simulated game activities (SGA) in throwing effectiveness and rotational strength of the shoulder; and b) the relationship between the rotational strength of the shoulder and ball velocity and accuracy in team handball Methods Sixteen female handball players participated following a SGA, which included distinctive handball activities for 60 min (2 halves of 30 min) For testing ball velocity and accuracy, every 10 min, subjects performed 3 shots on the spot towards a target from 7 m distance Shoulder isokinetic strength during internal (IR) and external rotation (ER) was evaluated in 3 angular velocities (60, 180, and 300 degrees /s) before SGA, during half-time and at the end of SGA Results Throwing effectiveness was significantly affected by time, as aiming accuracy was gradually decreased However, ball velocity remained stable The correlation between ball velocity and deviation was not significant throughout the SGA No statistically significant differences between measurements were found in maximum isokinetic torque, except from the case of ER at 180 degrees /s, where there was a significant difference between initial measurement (IM) and A and B halves A significant relationship between isokinetic torque and ball velocity was found only for the IM for ER (180, 300 degrees /s) and IR (300 degrees /s) Conclusion The main findings of this study are that, during a game simulation, time affects only aiming accuracy and not ball velocity or rotational strength of the shoulder Moreover, peak torque of IR and ER of the shoulder is not related with ball velocity and throwing effectiveness

Validity and reliability of self-assessment of sexual maturity in elite adolescent athletes.

Abstract: Aim The variability along the progression of different stages of maturation during puberty suggests that chronological age is not the best indicator in assessing biological status during adolescence. This is particularly relevant for adolescents involved in high level of sports competitions, which implies greater physiological and biomechanical demands to the body. Therefore, monitoring physical changes during this period may help the coaching and medical staff to construct and adapt on an individual basis, better training programs and, then, improve performance while preventing injuries. Thus, the aim of this study was to evaluate the validity and the reliability of self-assessment of sexual maturity among elite adolescent athletes. Methods Using the Tanner sexual maturity method, 24 male and 23 female athletes aged 12 to 17 years, were assessed by a physician, and, then, self-assessed for sexual maturity. Results Agreement with the physician ratings was high (k coefficients of 0.79 for pubic hair and 0.67 for genital development for boys and 0.75 and 0.85 for pubic hair and breast development for girls, respectively). Spearman correlations ranged from 0.86 to 0.97 (P= or Conclusion The self-assessment is a valid and reliable method to assess sexual maturity in elite adolescent athletes.

Physical activity and endurance in normal weight versus overweight boys and girls.

Abstract: Aim. Some studies found lower levels of physical activity and fitness in overweight children, compared to normal weight children, while others have failed to observe any difference. Therefore, the purpose of the present study was to reinvestigate the differences in physical activity and running capacity between overweight and normal weight children. Methods. A random sample of 121 males and 101 females, 11 to 13 years old, was selected. Children were divided into overweight/fat and normal weighUfat groups based on measures of body mass index and percentage of body fat. Physical activity level was assessed by accelerometers and a Physical Activity Questionnaire. Running capacity was measured by the Cooper Test. Results. Accelerometer data revealed that overweight/fat children were less moderate to vigorous physically active when compared to normal weight/fat children. They also performed worse on the running capacity test (P<0.001). Overweight children reported to be less active in leisure time (P<0.05) compared to normal weight children. Overfat girls reported to participate less in sports activities compared to normal fat girls (P<0.05). Conclusion. The present study found clear differences in physical activity and running capacity between overweight/fat and normal weight/fat 11- to 13-year olds. A major strength of the present study is that similar results were shown based on different estimates of overweight and activity in a relatively large sample of children.

The effects of acute static stretching on reaction time and force.

Abstract: Aim The purpose of this study was to determine alterations in explosive force production and reaction time following the soleus and gastrocnemius muscle stretching. Specifically we investigated whether or not actually stretching the calf muscles would alter the performance of reaction time and force production. Methods Fifteen subjects (age: 25.07+/-5.35 years; height: 1.76+/-0.07 m; weight: 81.38+/-17.28 kg) completed 2 test sessions. All subjects underwent a warm-up of 5 min bicycling and stretching of the ankle plantar flexors followed by reaction time and force tasks, and a similar control period of no stretch of the ankle plantar flexors. Measure of reaction time and force were assessed following stretching and no stretching conditions. Results There were no significant differences in reaction time and force between the stretching and control conditions (P>0.05). Conclusion These results demonstrated that 3 sets of 15 s duration of the static stretching did not have a positive or negative effect on reaction time and explosive force.

Movement patterns in elite Brazilian youth soccer.

Abstract: Aim. The aim of this study was to determine standards for the total distance covered (DC) and motion pattern characteristics of young Brazilian soccer players during competitive matches. Methods. Seventy-five young soccer players from 5 of the most successful soccer clubs of Sao Paulo's Soccer Federation were divided in 3 categories: under-15 years (U15), under-17 years (U17) and under-20 years (U20) with 25 soccer players in each age group. In the U15 each half lasts for 30 min, in the U17 40 min and in the U20 45 min. The individual measurements were made during games following accepted video-recording methodology. The players were grouped by position: fullbacks, wingers (WG), defensive midfielders, offensive midfielders (OMF) and strikers (STK). The following indices were determined: total distance, and distance jogging, walking, and sprinting. Age and position differences were determined by ANOVA. Results. The intensity of the U15 (118 m/min) was significantly greater (P<0.05) than U17 (108 m/min) and U20 (109 m/min). WG and midfielders show greater DC than the other players in all other positions. STK and OMF show increased sprinting in U15 and U17 groups, respectively, and WG in U20s. The U15 group showed the greatest mean intensity when the time of each group was corrected to meters per minute. Conclusion. The results show differences in running volume and intensity between the age groups during match play. The data suggest that earlier development, physical training and tactical organization in the young soccer player leads to a high level of energy during competition.

Effects of frequency of static stretching on straight-leg raise in elementary school children

Abstract: AIM The aim of this study was to evaluate the efficacy of different frequencies of a stretching exercise program on lower extremity range of motion (ROM) in prepubertal schoolchildren. METHODS A total of 62 children were divided into 3 groups (experimental groups: A, B; control group: C). Experimental group A performed hamstring stretches for 5 min during the Physical Education classes over a full school term (9 months), 2 sessions per week (31 weeks, 62 sessions of Physical Education). Experimental group B performed hamstring stretches for 5 min during the Physical Education classes and during a specific extracurricular physical activity, over a full school term (9 months), 4 sessions per week (31 weeks, 62 sessions of Physical Education and 62 sessions of after-school physical activities). Control group followed the standard class program of Physical Education classes. Hamstring flexibility was measured using the straight leg raise test before and after the program. RESULTS No significant differences were revealed in ROM before and after the Physical Education classes for the control group. However, significant improvements in ROM were shown in the two experimental groups (P<0.001). Four days per week produced a greater rate of gains in ROM (16.9 degrees) than 2 days per week (9.3 degrees). For all groups, the initial and the final ROM between the right and left sides were similar. CONCLUSION This study indicates that a full school term (9 months) incorporating static stretching as part of the Physical Education classes and the extracurricular physical activities significantly increases the ROM of the hamstrings in prepubertal schoolchildren. The study also suggests that the increase of the frequency of stretching is effective for increasing ROM.

Habitual physical activity levels in childhood and adolescence assessed with accelerometry

Abstract: AIM The purposes of this study were: 1) to evaluate age and gender differences in physical activity (PA) of children and adolescents; 2) to find out if children and adolescents fulfill the PA recommendations of 60 min x day(-1) of moderate (MPA) to vigorous PA (VPA) METHODS PA was assessed in 265 female and 238 male subjects, ranging from 6 to 18 years of age, grouped in 4 age groups, with MTI ActiGraph model 7164, during 7 consecutive days The MTI actigraph data was reduced to bouts (30-, 20-, 10-, and 5-min) and minutes spent in MPA, VPA, and very VPA (VVPA) RESULTS The oldest boys and girls revealed a lower number of PA bouts than the younger ones Significant gender differences were found in daily VPA, F(1, 492)=3767, P<0001; and VVPA F(1, 494)=2411, P<0001 Boys were more active than girls Significant age group differences were also found in MPA, F(3, 494)=874, P<0001; VPA, F(3, 492)=7815, P<0001; and VVPA, F(3, 454)=5489, P<0001 In both genders MPA, VPA and VVPA decreased with age Till the age of 14, children had means between 796+/-306 and 1441+/-769 min*day(-1) of PA After this age, there was a decrease to 441+/-199 min*day(-1) in girls and to 563+/-319 min*day(-1) in boys CONCLUSION Boys had more minutes a day of VPA and VVPA than girls PA decreased with age The subjects of this study, aged 6 to 15, fulfilled the recommendations of 60 min x day(-1) of MPA to VPA

Association between sleep quality and physical fitness in female young adults.

Abstract: Aim Sleep quality and physical fitness are critical for young adults' growth and health. However, no study has examined the association between sleep quality and physical fitness in young adults. Methods A total of 291 female college students (mean age: 19.3+/-0.6 years; mean height: 160.3+/-5.2 cm; mean weight: 52.2+/-9.8 kg), in the northern part of Taiwan, volunteered as subjects. For sleep quality evaluation, a valid Chinese version of the Pittsburgh Sleep Quality Index (PSQI) was used. For physical fitness testing, a battery of field-based health-related fitness tests was conducted by well-trained instructors. Data was analyzed using independent t-tests and the Pearson product-moment correlation coefficient. Results Subjects with poor sleep quality (P) (PSQI score >5) were more likely to have lower levels of muscular endurance, flexibility, and cardiovascular fitness. Significant correlations were also found between the global PSQI score and physical fitness performances in female young adults. Conclusion This study confirmed the high prevalence of P among young adults. Education materials should try to prevent young adults from developing poor sleep patterns and inactive lifestyles. Moreover, subjects with P should take better care of health problems from cardiovascular disease and musculoskeletal injury.

Competition, estimated, and test maximum heart rate.

Abstract: Aim. The aim of the present study was to compare the highest heart rate (HR) of soccer players recorded during competition matches with the maximum HR (HR max ) estimated from age and the highest HR recorded in effort tests within a single category (intracategory) and between categories (intercategories). Methods. The sample was made up of 19 under-17 athletes, 12 under-20 athletes and 14 professional athletes of a Brazilian first division soccer team. Players' HR was monitored during official competition matches and maximum effort test with a set of HR monitors. The highest HR recorded during competitive matches (MHR1) was considered as the highest HR value attained by each player during matches. HR max estimated from age (MHR2) was estimated by using the equation HR max = (220-age). The highest HR recorded in effort tests (MHR3) was determined as being the highest HR value recorded during a maximum effort test (1 000-m run). The Wilcoxon test was used in intracategory statistical analysis. The Kruskal Wallis test was used in intercategory statistical analysis. The significance level adopted was P<0.05. Results. In all categories, MHR3 was lower than MHR1. Concerning intercategory analysis, the three categories did not exhibit a difference in MHR1 results. Relative to MHR3, the under-17 and under-20 categories were not different from each other. These two categories exhibited larger MHR3 values than the professional one did. Conclusion. HR max measured during field tests can be underestimated in relation to that measured during competition activities, maybe because the tests represent an artificial situation for athletes, who do not feel as motivated as during competitions.

A prospective study of the relationships of autonomy, competence, and relatedness with exercise attendance, adherence, and dropout.

Abstract: Aim Given the need to investigate determinants of exercise behavior, the study examined the relationship of the needs for autonomy, competence, and relatedness with exercise attendance and adherence/dropout in organized exercise programs over 6 months A secondary purpose was to further determine the predictive validity of the Basic Psychological Needs in Exercise Scale (BPNES) responses Methods A prospective design was utilized where 108 male exercise participants (mean age: 2738 years) and 120 females (mean age: 2779 years) completed the BPNES before an exercise class Six months later, the total number of their visits to the fitness center over the 6-month period was assessed, as well as whether they still attended Results Latent variable structural equation modeling demonstrated that it was only the need for competence that significantly predicted exercise attendance and this was the case for both male and female participants, simultaneously Further, a binary logistic regression demonstrated that only the need for competence predicted group membership among participants who were categorized either as adherers or dropouts Conclusion The need for competence emerged as the main predictor of levels of exercise attendance and of exercise adherence/dropout group membership Moreover, the findings further supported and broadened the validity evidence base of the BPNES responses

Soccer half-time strategy influences thermoregulation and endurance performance

Abstract: AIM In the first 15 min of the second half in professional soccer, there is a reduction of high intensity distance covered and a high incidence of injuries sustained, possibly due to a reduction in body temperature during the half-time (HT). The aim of this study was to investigate the effect of active and passive re-warm-up strategies on cardiovascular (heart rate, HR) and thermoregulatory stress, and second-half soccer-specific endurance performance (SSEP). METHODS Seven professional players performed two intermittent field tests of 16.5 min duration, with a 15 min HT. On separate, randomised occasions, 4 trials were completed during which different HT strategies were undertaken between minutes 7 and 14 of the HT interval. Two passive trials were completed: rest control trial (CON), or players were immersed to the gluteal fold in a hot bath (approximately 40 degrees C-passive heating, PH); in the active trials, players performed at 70% maximum HR, either steady-state non-specific active heating (cycling, NSAH) or intermittent soccer-specific active heating (sprinting repeatedly, SSAH). HR and core temperature (Tc) were measured every 5 min, and body weight was recorded pre and post each trial. RESULTS Active re-warm-up strategies maintained SSEP in the second period with respect to CON (P 0.05). Active heating strategies increased HR during HT in comparison to CON, whereas PH did not. During the HT period in the CON trial, T(c) decreased by 0.97+/-0.29 degrees C, PH and SSAH trials did not attenuate this decrease (P>0.01), whereas NSAH increased T(c) in respect to CON (P<0.01). These differences in HR and T(c) between re-warm-up strategies during HT were not apparent at the end of the trials. CONCLUSION Active re-warm-up strategies during HT attenuated the decrement in second-half SSEP that was observed during passive trials.

The relationship between isokinetic knee extension and flexion strength with soccer kick kinematics: an electromyographic evaluation.

Abstract: Aim The purpose of this study was to investigate the relationship between isokinetic strength knee testing and soccer kick kinematics using electromyography (EMG). Methods Thirteen pubertal soccer players (age: 14.3+/-0.4 years) performed maximum instep soccer kicks, while knee angular position of the swinging leg was recorded using a twin-axis electrogoniometer. Bipolar surface EMG activity of the vastus medialis, vastus lateralis and biceps femoris (BF) muscles was recorded. The subjects also performed maximum knee extension and flexion efforts at concentric angular velocities of 1.04, 3.14 and 5.23 rad x s(-1) and eccentric angular velocities of 1.04 and 3.14 rad x s(-1). Results The correlation coefficients between isokinetic moments and knee angular velocity values during the kick ranged from 0.609 to 0.898 for concentric moments and from 0.431 to 0.612 for eccentric moments. Agonist EMG values during isokinetic tests ranged from 63.17+/-19.9% to 128.7+/-34.9% maximum voluntary contraction (MVC). Antagonist EMG levels ranged from 9.76+/-6.12% to 36.91+/-22.81% MVC. The corresponding EMG values during the soccer kick ranged from 12.78+/-6.8% to 122.34+/-61.5% MVC and increased as the foot approached the ball. Conclusion Isokinetic tests at intermediate and fast angular velocities are adequate for monitoring strength training programs in soccer. However, muscle activation patterns differ between the two movements, especially those of the BF muscle.

The effect of an ultra-endurance running race on mucosal and humoral immune function.

Abstract: Aim. There are reports of the effect of endurance exercise on mucosal immune function and of the effect of short duration exercise on humoral immune function. However, little is known of the effect of endurance exercise on humoral immune function and the related risk of infection. This study examined the effects of an ultra-endurance running race on salivary immunoglobulin-A (s-IgA), serum IgA, leukocyte subset concentrations and the incidence of upper respiratory tract infections (URTI). Methods. Thirteen male and 4 female competitors provided saliva samples and blood before and at several times after the running race. Self-reported symptoms of URTI were also recorded for 2 weeks before and 2 weeks after the race. Results. Salivary IgA secretion rate (P=0.005) and ratio to osmolality (P=0.006) were lower immediately postrace and decreased further for at least 2 more h. s-IgA secretion rate had not returned to normal the next morning (P=0.009). Serum IgA concentration was lower post- than prerace (P=0.003) and was even lower the next morning (P<0.001). Leukocyte concentration was elevated postrace (P<0.001), mainly because of an increase in neutrophils (P<0.001) and both remained high the morning after the race (P<0.001). Lymphocyte concentration decreased postrace (P<0.001) and was still depressed the next morning (P=0.032). The incidence of symptoms of URTI was the same in the two 2-week periods before and after the race. Conclusion. These findings support the hypotheses that an ultra-endurance run may adversely affect mucosal immunity and cause significant changes in the concentration of leukocyte subsets.

Effect of a single bout of exercise on the mood of pregnant women.

Abstract: Aim Few studies have been conducted investigating the psychological benefits of exercise during pregnancy Additionally, hormonal and cardiovascular responses to water-based and land-based exercise in pregnant women are different Therefore, this study investigated the influence of a single bout of exercise on the mood of pregnant women participating in an aqua- or studio-based exercise class compared to a parentcraft and a control group Methods The study consisted of 4 conditions: the 66 participants either took part in an aqua class, a gym studio class, a parentcraft class or acted as controls Mood was assessed using the profile of mood states (POMS) just prior to the activity and shortly following the activity Results No initial differences were observed between the four conditions before exercise or activity participation However, participation in the aqua and studio conditions resulted in increased overall mood score and showed a significant increase on the vigor subscale Also, a decrease in the depression subscale of the POMS was found in the aqua condition The parentcraft classes did not alter the women's mood state Conclusion Although the physiological and hormonal reactions are different for aqua- and land-based exercise both modes of exercise appear to be equally beneficial for pregnant women to engage in to improve mood Additionally, exercise, but not parentcraft classes, resulted in enhanced mood in women in their 2nd or 3rd trimester of pregnancy Although exercise has mood benefits that are comparable to other mood management techniques, it also has additional physiological and physical benefits to both the mother and the fetus

ACE I/D gene polymorphism and aerobic endurance development in response to training in a non-elite female cohort.

Abstract: Aim. The aim of this study was to investigate the association between ACE gene polymorphism and short- and medium-duration aerobic endurance performance improvements in response to the same training regimen in a non-elite female cohort. Methods. Fifty-five female non-elite Caucasian Turkish athletes trained to enhance running speeds corresponding to 70% and 90% of heart rate reserve (V-HRR70 and V-HRR90 respectively) 30 min running speed performance (V-30min) 3 times per week, for 6 weeks. ACE gene polymorphisms studied by PCR analysis. Results. The distribution of genotypes in the whole cohort was 21.8%, 41.8%, 36.4% for II (n=12), ID (n=23) and DD (n=20), respectively. Subjects with ACE II genotype had significantly higher improvements in V-30min and V-HRR70 than the ACE DD group (P ID>DD (P ID>II (P<0.01) observed in V-HRR90. Conclusion. ACE II genotype may related with better improvements in medium duration aerobic endurance performance whilst ACE DD genotype seems to be more advantageous in performance enhancement in shorter duration and higher intensity endurance activities.

Branched-chain amino acids supplementation attenuates the accumulation of blood lactate dehydrogenase during distance running

Abstract: AIM We investigated the effect of branched-chain amino acids (BCAA) supplementation on tissue damage during distance running. METHODS Eight male distance runners (mean +/- standard deviation; age: 20.4+/-1.2 years, body weight: 58.4+/-4.2 kg) participated in a double blinded cross over designed study conducted during training camp. During each intervention period, the subjects were asked to participate in a 25-km run, and the blood BCAA and lactate dehydrogenase (LDH) level, an index of tissue damage, were measured pre- and post-run. Either a drink containing BCAA (0.4% BCAA in a 4% carbohydrate solution) or an iso-calorie placebo drink was provided to the subjects 5 times during the run without any restriction in the volume. RESULTS The total volume of the drink consumed by the subjects did not differ substantially between the trials: 591+/-188 (2.36 g BCAA) vs 516+/-169 mL in BCAA and placebo trial, respectively. During the run, the blood BCAA concentration was maintained in the BCAA trial. However, the blood BCAA concentration level tended to decrease in the placebo trial (P<0.1). The extent of the blood LDH increase in the BCAA trial was significantly less than that of the placebo trail (48% vs 58%, P<0.05). CONCLUSION Maintaining the blood BCAA level throughout a long distance run contributes to a reduction in the LDH release and, therefore, the effect of BCAA supplementation is suggested to reduce the degree of muscle damage.

Influence of a medium-impact aquaerobic program on health-related quality of life and fitness level in healthy adult females.

Abstract: Aim. The aim of the study was to examine the influence of a medium-impact aquaerobic program on the health-related quality of life (HRQoL) and health-related fitness (HRF) lev- el of middle-aged healthy female subjects. Methods. Twenty apparently healthy women (mean age: 43.1 (standard deviation: 9.7) years) participated in the study. Criteria for inclusion were absence of diagnosed illnesses, as well and signs and symptoms of disease as evaluated by the Physical Activity Readiness Questionnaire. Participants carried out a medium-impact aquaerobic exercise program consisting of 2 weekly sessions of 60 min during 8 months. Before and after the exercise program, HRQoL was assessed by the 36-item short form health survey (SF-36) questionnaire, and HRF was mea- sured using a simplified version of the AFISAL-INEFC HRF test battery. Results. Following the exercise program, an increase in all domains of HRQoL, except general health and role-emotion- al, was observed. Total body mass and body fat percentage decreased, and estimated aerobic power increased. Conclusion. Completion of a medium-impact aquaerobic pro- gram (2 weekly sessions of 60 min during 8 months) improves HRQoL in most domains, particularly bodily pain and vitali- ty, and shows to be among the most effective programs for improving perceived quality of life. Moreover, this exercise program proved to have a positive influence on the body com- position and functional capacity of the subjects, being effective in reducing fat body mass and improving cardiorespiratory function.

Injury survey in competitive sub-elite rhythmic gymnasts: results from a prospective controlled study.

Abstract: AIM: The aim of this study was to determine the frequency, anatomical site and types of injury incurred in rhythmic gymnastics. METHODS: An 8-month prospective and controlled injury survey was planned, including 70 club-level competitive rhythmic gymnasts, aged 13-19 years. Information on injury events was recorded weekly in an injury record booklet for any event occurring over that week. Height, weight, anthropometric measurements and time spent in physical activity were recorded at baseline. Data from 72 age-matched non-athletic females served as controls. RESULTS: Forty-nine significant injuries were reported by gymnasts and 34 by controls (70% vs 47%, P<0.005, odds ratio 2.28); gymnasts sustained a rate of 1.08 injuries per 1 000 h of training. The most prevalent anatomical sites sustaining injury were the ankle and the foot (38.9%), followed by back (22.2%). Strains and sprains were frequently reported both in gymnasts and in controls. Gymnasts missed an average of 4.1 days of physical activity as compared to 18.9 days for the control females. Alternatively, modification of training sessions occurred more frequently for the gymnast group (32 vs 7 cases for controls). The total school days missed were lower for the injured gymnasts than for the injured controls (27 vs 64 days). CONCLUSION: Competitive, club-level rhythmic gymnastics show a higher prevalence of injuries than non-athletic controls, but considering the high number of hours spent in training sessions, it derives that rhythmic gymnasts is a sport discipline at relatively low risk of severe injuries. These are mainly limited to back and lower limbs, are generally not severe and do not significantly hinder the preparation for the competitions. Language: en

Anthropometric profiles of elite Asian female handball players.

Abstract: Aim Handball has increased in status as a sport since its introduction in 1972 into the Summer Olympic Games. Whereas anthropometric profiles of female athletes have been reported for certain sports, data for elite handball players are limited. The current study was based on anthropometric measurements of 60 female Asian handball players competing in the continental championship, the aim being to identify any differences between countries and between playing positions. Methods The setting was the 12(th) Asian Games in Hiroshima, Japan. Anthropometric data were obtained from 60 players including teams from China, Japan, Kazakhstan and South Korea. Measurements included height, mass, skinfold thicknesses: from these measures percent body fat and muscle mass were estimated. Profiles were compared between 4 nations and 4 positional roles by means of ANOVA. Results Overall, mean (SD) values were 1.708 (0.068) m, 64.6 (7.7) kg, 20.8% (4.4%), 39.6% (5.2%) for stature, mass, percent body fat and percent muscle mass, respectively. There were small differences between players from different countries but no significant (P>0.05) influence of playing position. Players from Japan were shortest, lightest and lowest in adiposity. The Chinese players were tallest and had the greatest muscle mass. Conclusion These female international handball players differed in some respects in anthropometric characteristics according to their country of origin. The Asian players were found to be relatively homogeneous across the different positions.