Effects of long-term detraining on muscle performance in young soccer players.

BACKGROUND: Long-term detraining consists of a physiological partial or total reduction of the adaptations induced by training caused by a suspension period of the training itself longer than 4 weeks. The aim of this study was to analyze a group of young soccer players by assessing the effects of long-term detraining on neuromuscular performance. METHODS: A study sample of 35 young soccer players of subelite level (age: 14.5±0.5 years) was recruited. The subjects were tested 7 days before the interruption of training for the summer break (T0), and at the end of the 7-week detraining period (T1). RESULTS: No statistically significant differences were found for BMI (P=0.283) and percentage of fat mass (P=0.273) between T0 and T1. PUSH UP (P=0.016; ES [effect size]=0.2) and SIT UP (P=0.001; ES=1.2) test values show statistically significant increase, those of CHIN UP (P=0.05; ES=-0.2), instead, a statistically significant worsening. Statistically significant but moderate differences on speed running test 30 meters (P=0.001; ES=0.3) are observed as well as trivial differences on 50 meters (P=0.001; ES=0.2), while differences on 10, 15 and 20 meters are irrelevant. As for the jump tests, values show a slight worsening (P=0.135; ES=0.2) in Squat Jump and Counter Movement Jump (P=0.153; ES=0.2) without statistical significance. CONCLUSIONS: A 7-week-long detraining period does not seem to produce any appreciable changes on neuromuscular performance of the lower limb (trained muscle) in young soccer players. As regards the analyzed age group, coaches should not focus their attention on neuromuscular efficiency maintenance exercises in the off-season period.

A Study about a New Standardized Method of Home-Based Exercise in Elderly People Aged 65 and Older to Improve Motor Abilities and Well-Being: Feasibility, Functional Abilities and Strength Improvements.

BACKGROUND: To verify the effects in terms of feasibility, strength and functional abilities of a standardized exercise training method that is partially supported (home training), with the aim of improving motor abilities and well-being. METHODS: A total of 67 participants underwent two sessions per week for 12 weeks for the program, based on 8 sequences with specific body part targets, with each sequence made up of 9 exercises. OUTCOME MEASURES: Recording of training session data, Chair Test, Hand Grip Test, Timed Up-and-Go Test, Stork Balance Test, Sit-and-Reach Test, VAS, Perceived Physical Exertion. RESULTS: In total, 97% of the sample were "adherent" (more than 70% of the prescribed treatments performed). The rate of adverse events was infrequent (only 8). Chair Test +31%, Hand Grip Test +6%, Timed Up-and-Go Test -17%, Stork Balance Test +65%, Sit-and-Reach Test +55%, VAS -34%, Perceived Physical Exertion -69%. CONCLUSIONS: Home training has good feasibility (adherence, tolerability, safety) and cost-effectiveness ratio and improves both strength and functional abilities, which, in turns, helps to improve motor abilities and well-being.

Physical Characteristics and Performance Tests in Male Water Polo: A Multiple Regression Analysis on Youth.

BACKGROUND: In water polo, more physical and performance variables are related to a performance in a match. The aim of our work was therefore: (a) to evaluate the relationships between anthropometric characteristics and performance tests and performance in a match in young male water polo players; (b) to propose new guidelines for match analysis. METHODS: Multiple regression analysis was used to study the results in anthropometric evaluations (height, body mass, chest circumference, arm span, non-dominant arm length) and performance tests (push-up, chin-up, shuttle swim test, sprint swim 10 m, eggbeater kick, 100 m swimming) and two coaches' evaluations of two friendly matches using new guidelines. A total of 130 subjects (age: 15.6 ± 0.9 years) were involved in the study. RESULTS: In this study, we proposed a new performance model based on multiple regression analysis (r = 0.85, r2 = 0.73, adjusted r2 = 0.57) and described by the following equation: Coach's Evaluation = 151.6 + (-0.016 × height) + (0.6 × body mass) + (-0.82 × chest) + (-0.59 × arm span) + (0.75 × non dominant arm length) + (-0.037 × push up) + (0.17 × chin up) + (5.87 × shuttle swim test) + (-2.2 × 10 m sprint swim) + (0.05 × eggbeater kick) + (-0.35 × 100 m swimming). Inter-observer values were: CV: -3.9%, ICC: 0.82, ES: 0.1. Intra-observer: CV: -4.1%, ICC: 0.96, ES: 0.06. CONCLUSIONS: The relationships between anthropometric and performance variables and the match analysis have been statistically described. The equation found can be used to predict the overall performance of a player and permits evaluations of how much the improvement in one of the qualities can affect the players' overall performance. Moreover, the new method for match analysis we have proposed showed a good reliability and can be used for new studies on water polo.

New aspects for match analysis to improve understanding of game scenario and training organization in top-level male water polo players.

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, Gwangju, South Korea, 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 (CI 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.

Physical and performance variables for talent identification in water polo.

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.

Use of the pedometer in the evaluation of the effects of rehabilitation treatment on deambulatory autonomy in patients with lower limb arthroplasty during hospital rehabilitation: long-term postoperative outcomes.

[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.

Body composition analysis to study long-term training effects in elite male water polo athletes.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

New approach to evaluate late arm impairment and effects of dragon boat activity in breast cancer survivors.

To verify the applicability of a new approach based on the strength curves (SCs) methodology in late arm impairment in breast cancer (BC) survivors and to evaluate the effects of dragon boat (DB) activity on the late regaining of the muscle strength, upper limb impairment, and quality of life in patients undergoing surgery for BC.Retrospective observational study on 64 subjects (54.5 ±â€Š9.7 years), 47 of them had undergone unilateral mastectomy surgery and were evaluated for late arm impairment. A clinical evaluation of the shoulder and compilation of functional assessment (DASH, Rowe, Constant-Murley) and quality of life (SF-36) scales were carried out. Assessment of muscle strength with SC obtained with isometric assessments and serratus anterior muscle test were performed.Differences between the SC are evident between healthy and operated subjects. Among the 3 groups of operated subjects the difference in strength is maximum at 0°. Statistically significant difference was found between operated and nonoperated only in SF-36 scale. No significant difference was found between groups for shoulder instability and winged scapula.The SC can be used in the study of upper limb impairment after surgery for BC: measurements carried out at 1st degrees of the range of motion are more useful for clinicians. DB activity is useful to reduce the late arm impairment.

Anthropometric and performance measures to study talent detection in youth volleyball.

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.

Shuttle swimming test in young water polo players: reliability, responsiveness and age-related value.

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.

Physical exercise modulates the level of serum MMP-2 and MMP-9 in patients with breast cancer.

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.

Ambulatory assessment of shoulder abduction strength curve using a single wearable inertial sensor.

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 <1 degree (p = 0.37). This study showed the effectiveness of using a single wearable IMU for the assessment of strength curve during isoinertial movements in a way that complies with the needs of clinicians in an ambulatory setting.

Testing and Training of the Eggbeater Kick Movement in Water Polo: Applicability of a New Method.

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.

Late Isometric Assessment of Hip Abductor Muscle and Its Relationship with Functional Tests in Elderly Women Undergoing Replacement of Unilateral Hip Joint.

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.

Performance analysis in saber.

Fencing is a sport practiced by both men and women, which uses 3 weapons: foil, épée, 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.