The decision-making in dribbling: a video analysis study of U10 soccer players' skills and coaches' quality evaluation.

Introduction: Dribbling is an important soccer skill that, when effective, allows players to overcome opponents. It can provide a strong tactical advantage; for this reason, all of its components (sprint, speed, and ball control) are fundamental to the development of young players. Dribbling can also be considered a decision-making process, and due to its characteristics, it is not always easy to study ecologically. Using a video analysis study, this research aimed to determine whether dribbling skills, specifically dribbling choice (i.e., decision-making), were related to U10 soccer players' quality. Methods: Several outcomes measures, divided into three categories, were taken during video analyses: (i) measures related to the efficacy of dribbling skill; (ii) measures related to the ability of players without the ball to support the player in possession; and (iii) measures related to ball circulation. These data were retrospectively assessed to whether the coaches had formed the teams in training through an implicit knowledge of the players' dribbling skills. Results: The percentage of accurate dribbling (that is, the ability to perform correct passes after a successful dribble) was found to be the variable that coaches may have implicitly used in creating the three groups differentiated by technical skills (p < 0.05). In fact, this percentage was 12.9%, 24.0%, and 48.1% for the groups with lower, average, and higher technical skills, respectively. Conclusion: Overall, the results demonstrate that dribbling accuracy has an important weight in the coach's evaluation of the technical skills level of young soccer players.

Influence of training status on cardiac and vascular functioning in young recreational and competitive male rowers.

Introduction: The aim of the study was to investigate the influence of training status on cardiovascular function in young male recreational and competitive rowers. Methods: Ejection duration in percentage to the heart rate period (ED%), subendocardial viability ratio (SEVR), augmentation index at 75 bpm (AIx75) and carotid to femoral pulse wave velocity (cf-PWV) of competitive rowers (CR) (age 17.6 ± 4.1 years), recreational rowers (RR) (age 16.7 ± 2.70 years) and athletes practicing other recreational sports (ORS) (age 15.3 ± 1.4 years) were assessed. Results: ED% was lower in CR compared to ORS (31.9 ± 3.9% vs. 38.4 ± 4.8%; p = 0.026) and cf-PWV was higher in CR compared to ORS (5.5 ± 1.0 m/s vs. 4.7 ± 0.5 m/s; p = 0.032). SEVR was higher in CR compared to RR and ORS (165.8 ± 33.7% vs. 127.4 ± 30.4% and 128.3 ± 27.8%; p = 0.022) and AIx75 was lower in CR compared to RR and ORS (-15.7 ± 8.6% vs. 1.2 ± 9.9% and 1.5 ± 9.1; p = 0.001). Discussion: Healthy, young competitive male rowers reported higher myocardial performance and better cardiovascular health than recreational athletes. Interpretations of cf-PWV in competitive rowers should be performed alongside other cardiovascular indicators.

Chronic Effects of Asymmetric and Symmetric Sport Load in Varsity Athletes across a Six Month Sport Season.

The relation between specific sport practice and possible spine modifications is unclear. The aim of this study was to investigate the effects of different sports on the spine in adult varsity athletes across a six month sports season. Forty-four athletes (24.5 ± 3 years) were divided into two groups according to the typology of the sport practiced: the symmetric sports group (S, 22 athletes: track and field running, n = 14; cycling, n = 8), and the asymmetric sports group (A, 22 athletes: tennis, n = 22). The participants' spines were evaluated with Formetric® 4D rasterstereographic analysis at the beginning (BL), in the middle (INT), and at the end (FIN) of the season. Twenty-five parameters were measured in an average 4D modality. The results showed that the intervention factor (BL vs. FIN) had a significant effect on dimple distance (p < 0.05) and on left lateral deviation (BL vs. FIN and INT vs. FIN, p < 0.01 and p < 0.01, respectively). Statistical differences were found for the sport typology factor for pelvic antero-retroversion and right lateral deviation. For left lateral deviation, no modulation was found for the sport typology. Asymmetric versus symmetric sport loads showed small statistical differences in a non-professional sample of adult athletes. The practice of asymmetric sports should also be encouraged without exceeding the total number of hours per week.

Live Streaming vs. Pre-Recorded Training during the COVID-19 Pandemic in Italian Rhythmic Gymnastics.

The SARS-CoV-2 outbreak led to an inevitable and drastic transition to online training systems. This study aimed to analyze the differences between live-streaming and pre-recorded training modalities in rhythmic gymnastics (RG) with coaches and gymnasts of different technical levels. A total of 238 coaches and 277 athletes affiliated with the Italian Gymnastics Federation (FGI) participated in the study. The data collection tool was a self-collected questionnaire structured in three sections: participant's information, characteristics of live-streaming training, and characteristics of pre-recorded training. A 2 × 2 ANOVA was used for each numeric variable. A Pearson's chi-squared test was used for each categorical variable. For the athletes, training frequency, motivation, and efficacy were significantly higher (p < 0.05) with live streaming (3.7 ± 1.5 day/week, 3.8 ± 0.9 score and 3.8 ± 0.8 score, respectively) than with a pre-recorded modality (2.2 ± 1.7 day/week, 3.1 ± 1.2 score and 3.7 ± 0.9 score, respectively), while for coaches, significant differences (p < 0.005) were found between the two modalities only for training frequency (live streaming, 3.6 ± 1.8 days/week vs. pre-recorded, 2.1 ± 1.7 days/week). The adherence (number of No:Yes) was significantly higher (p < 0.05) for the live-streaming modality than for the pre-recorded modality in gold athletes (1:74 vs. 14:61, respectively), silver athletes (12:190 vs. 28:174, respectively), and gold coaches (3:63 vs. 11:55, respectively), but it was not for silver coaches. Physical preparation was performed significantly (p < 0.005) more often (number of No:Yes) for live streaming than for the pre-recorded modality by gold athletes (9:66 vs. 34:41, respectively), silver athletes (25:177 vs. 77:125, respectively), gold coaches (8:58 vs. 37:29), and silver coaches (33:139 vs. 85:87, respectively). Free body technical preparation was performed significantly (p < 0.005) more often (number of No:Yes) for live streaming than for the pre-recorded modality by gold athletes (15:60 vs. 39:36, respectively), silver athletes (84:118 vs. 121:81, respectively), gold coaches (10:56 vs. 38:28), and silver coaches (60:112 vs. 105:67, respectively), while no differences were found for silver athletes' and coaches' technical preparations for apparatus training between the two modalities. In conclusion, live streaming had greater positive effects on RG training during home confinement. However, pre-recorded training could be more effective for some types of training, depending on the technical level of the athletes.

Effects of Acute Whole-Body Vibration Practice on Maximal Fat Oxidation in Adult Obese Males: A Pilot Study.

OBJECTIVE: Whole-body vibration (WBV) training has been established as a useful method to improve physical fitness in obese individuals. However, the effects of WBV exercise on maximal fat oxidation (MFO) have not been examined in obese subjects yet. METHOD: MFO was eval-uated during a cardiopulmonary exercise test (CPET) on a treadmill in 12 adult obese males (BMI = 34.9 ± 3.3 kg/m2) after three different warm-up conditions: static half squat plus WBV (HSV), static half squat without WBV (HSWV), and rest (REST). Cortisol levels were evaluated before and after the warm-up, and 1 min (T1), 10 min (T10), and 30 min (T30) of the recovery phase. RESULTS: MFO was significantly higher in HSV (p = 0.013; 569.4 ± 117.9 mg/min) and HSWV (p = 0.033; 563.8 ± 142.9 mg/min) than REST (445.5 ± 117.9 mg/min). Cortisol concentrations at T1 were significantly higher in HSV (p = 0.023) and HSWV (p = 0.015) than REST. Moreover, cortisol concentrations were significantly lower at T30 than T1 in HSWV (p = 0.04). No differences were found between T30 and T1 in HSV. CONCLUSIONS: Active warm-up increases MFO; however, vibration stimulus during half squatting does not increase MFO during a CPET in obese subjects. The lack of significant differences of cortisol concentrations in HSV during the recovery phase might suggest a long-term effect of WBV on the endocrine system.

Relationship between individual ventilatory threshold and maximal fat oxidation (MFO) over different obesity classes in women.

OBJECTIVE: The use of the Individual Ventilatory Threshold (IVT), as parameter to prescribe exercise intensity in individuals with obesity, has become more frequent during the last years. This study aimed to evaluate the relationship between IVT and Maximal Fat Oxidation (MFO) in women with obesity. METHODS: Fifty-two obese female adults (age = 43.6±10.9 years; BMI = 38.5±5.2 kg/m2) were included in this study. According to the BMI classification, subjects were divided into three groups: Obese Class I (OBI, n = 16); Obese Class II (OBII, n = 20) and Obese Class III (OBIII, n = 16). All subjects performed an incremental graded exercise test to evaluate peak oxygen uptake (VO2peak), IVT and MFO. MFO was evaluated using a stoichiometric equation. Fat max zone was determined for each subject within 10% of fat oxidation rates at MFO. For each HR, %HRmax, VO2 and %VO2peak variable, Pearson's correlation test was done between IVT and MFO exercise intensity. When statistical correlation was found we used a comparative statistical analysis to assess differences between IVT and MFO. Statistical significance was set at P ≤ 0.05. RESULTS: For each HR, %HRmax, VO2 and %VO2peak variable there was a positive significant correlation (P<0.01) between IVT and MFO. No significant differences were found for HR, %HRmax, and VO2 between IVT and MFO. %VO2peak was significantly higher at IVT than at MFO (P = 0.03). MFO rates were significantly higher in OBIII women than in women of the other two classes. In all subjects, IVT was within the fat max zone. CONCLUSION: The use of HR and VO2 corresponding to IVT could be a useful parameter not only to improve cardiorespiratory fitness but also to prescribe physical activity that maximize fat oxidation in obese subjects.

Effects of body weight loss program on parameters of muscle performance in female obese adults.

BACKGROUND: Body weight loss program may lead to a decrease in lean body mass affecting negatively muscle performance in obese subjects. Thus, the aim of this study was to examine the effect of weight loss on muscle performance in female obese subjects. METHODS: Eighty obese female adults were enrolled for a 2-month unsupervised aerobic training (UAT) plus nutritional program. In the pre- and postintervention body composition was evaluated by hand-to-foot bioelectrical impedance method, body strength using handgrip test, and lower muscle power was assessed by a 5-repetition chair stand test (CST) and 30-s chair stand test (30sCST) wearing a dynamometer. RESULTS: Thirty-six subjects completed the protocol, 39% had high compliance (HC), while 61% had low compliance (LC) to exercise prescription. HC group showed a significant decreased body weight, percent of fat mass and lean muscle mass after training. Both groups significantly increased CST performance while only HC significantly increased 30sCST. No differences were found in CST muscle power in both groups between pre- and post-training. However, evaluation of muscle power during 30sCST showed significantly higher value in HC group than LC group after training. CONCLUSIONS: The results of our study show that although total lean muscle mass decreased after UAT, lower body muscle efficiency increased while muscle power did not change suggesting that in obese patients UAT can help to optimize weight loss and body efficiency. The data might be helpful for exercise professionals to evaluate correctly the muscle performance in obese adults after weight loss programs.

Prediction equation to estimate heart rate at individual ventilatory threshold in female and male obese adults.

OBJECTIVE: Prescribing individualized moderate exercise intensity is a useful method to reach positive effects on health status in obese adults. This study aimed to establish a practical reference equation to estimate the heart rate (HR) at individual ventilatory threshold (IVT) (HRIVT). METHODS: One hundred sixty-one obese subjects were clinically evaluated and characterized by anthropometric and body composition. Participants performed the six-minute walking test (6-MWT) and the cardiopulmonary exercise test to assess IVT. Multiple regression analysis for HRIVT, including 6-MWT, anthropometric, and body composition parameters, as independent variables, was performed for both gender separately. A cross-validation study was also performed to determine the accuracy of the prediction equation. RESULTS: Whereas HRIVT was not significantly different between males (121.5±18.3 bpm) and females (117.6±17.1 bpm), it differently correlated with physical and performance parameters. Therefore, two sex-specific equations were developed including 6-MWTHR and HRrest (R2 = 0.69 and 0.65 and root mean square errors of 8.8 and 10.1 bpm for females and males, respectively). CONCLUSION: In conclusion, in female and male obese adults, the 6-MWT might be used to predict HR at IVT. These outcomes are useful to prescribe optimal physical activity intensity when gold standard methods (e.g. gas exchange analysis) are unavailable.