Kinematics and Kinetics of Bulgarian-Bag-Overloaded Sprints in Young Athletes

Background: Eective sprinting requires large acceleration capabilities. To accelerate, large amount of force must be produced and applied eectively. The use of dierent implements such as sleds and vests can increase the amount of force produced and alter sprinting eectiveness. We propose the use of increasing overload via the Bulgarian Bag (BB) as a means to modify athletes\u2019 sprint and acutely increase force and power production. Methods: 24 young athletes performed three sprints over 20 m in three dierent conditions: unloaded (BW) and loaded with BB weighing 2.5% (BB2.5) and 5% (BB5) of the athlete\u2019s body mass. Sprint times at 2.5, 5, 10, 15, and 20 m were acquired and used to compute the force\u2013velocity relationship for the sprints. Maximal velocity (V0), peak force (F0), peak power (PP), and decrease in ratio of force (DRF) were computed. Results: the additional load caused a decrease in sprint times (p < 0.05) and V0 (p = 0.028), conversely no dierences were found for F0 (p = 0.21), PP (p = 0.50), and DRF (p = 0.83). Conclusions: Based on those findings, BB can be an alternative method to eectively overload sprint training toward improving sprinting performance

Mental fatigue impairs physical activity, technical and decision-making performance during small-sided games

The aim of this study was to investigate the effects of mental fatigue on physical activity, technical and decision-making performance during small-sided games. Nine sub-elite soccer players were enrolled in the study. The players performed two small-sided games on two occasions within a crossover experimental design. Before each game, they underwent a mental fatiguing task (Stroop task) and a control task (documentary watching) in a randomized, counterbalanced order. Players' physical activity, technical, and decision-making performance were obtained during small-sided games by GPS and video scouting. Results showed that distance in acceleration covered per min, negative passes, passing accuracy, and shot accuracy were likely impaired than control task after a mental fatiguing protocol. Decision-making performance of negative passes, passes accuracy, and dribbling accuracy resulted also likely decreased compared with control task. These findings demonstrated that mental fatigue impacted on technical, GPS-derived, and soccer-specific decision-making performance during SSG. In conclusion, avoiding cognitively demanding tasks before playing soccer-specific activities may be advisable to preserve players' physical activity, technical, and decision-making skills

L’utilizzo del functional movement screen in ambito scolastico

The reduction in basic movement patterns is the actual trend in preschoolers with a concomitant increase of bodyweight and inactivity status. The aim of this study was to investigate gender and age differences in Functional Movement Screen (FMS) scores in secondary school children.One hundred and one, Italian, students (age birth= from 1996 to 2001 y, height=172±5.0 cm, mass=64.2±0.1 kg) took part at this study. All participants were evaluated at school using the FMS before the physical education lesson.Secondary female showed higher scores in FMS Composite Score, Shoulder Mobility and Active Straight Leg Raise compared to their counterparts (p<0.05). On the other hand, males scored higher on Trunk Stability Push Up (p=0.0279) than female students. The age do not have any significant interaction with functional performance. Finally, fifty-seven of sixty-eight males andnineteen of thirty-three females healthy students scored 14 or less on the FMS Composite Score (p=0.0041). Students are encouraged to practice physical activity, both at school in classroom with many movement-breaks or in their leisure time, to limit the negative trend of functional performance. Teachers at school could also consider the FMS as suitable option inside the physicalfitness battery tests to detect movement competences of their students.Il trend evolutivo attuale delle capacità motorie tra i giovani risulta essere negativo, abbinato ad un aumento dell’inattività e del sovrappeso. Lo scopo dello studio è quello di indagare se differenze di genere e di età possono condizionare i punteggi del Functional Movement Screen (FMS) in giovani studenti. Centouno soggetti appartenenti alla scuola secondaria di secondogrado (anno di nascita= dal 1996 al 2001, altezza= 172±5.0 cm, peso corporeo= 64.2±0.1 kg) hanno partecipato allo studio. Tutti i soggetti sono stati valutati a scuola attraverso il sistema FMS prima dello svolgimento delle lezioni curriculari di educazione motoria. Le ragazze mostrano dei punteggi FMS maggiori del Composite Score, Shoulder Mobility ed Active Straigth Leg Raiserispetto ai ragazzi (p<0.05). Di contro, i ragazzi hanno ottenuto un punteggio significativamente maggiore Trunk Stability Push Up (p=0.0279). L’età anagrafica non ha nessun effetto significativo sui punteggi FMS. Infine, cinquantasette su sessantotto maschi e diciannove su trentatre femminehanno ottenuto un punteggio complessivo FMS minore di 14 (p=0.0041). In conclusione i ragazzi sono incoraggiati a svolgere attività fisica, sia in classe attraverso dei “break” di movimento sia nel tempo libero, al fine di limitare il trend negativo a livello motorio. Inoltre l’FMS potrebbe essere considerato uno strumento utile per misurare il livello delle competenze motorie degli studenti da parte degli insegnanti di educazione motoria

ITALIAN CONSENSUS STATEMENT (2020) ON RETURN TO PLAY AFTER LOWER LIMB MUSCLE INJURY IN FOOTBALL (SOCCER)

Return to play (RTP) decisions in football are currently based on expert opinion. No consensus guideline has been published to demonstrate an evidence-based decision- making process in football (soccer). Our aim was to provide a framework for evidence-based decision-making in RTP following lower limb muscle injuries sustained in football. A 1-day consensus meeting was held in Milan, on 31 August 2018, involving 66 national and international experts from various academic backgrounds. A narrative review of the current evidence for RTP decision-making in football was provided to delegates. Assembled experts came to a consensus on the best practice for managing RTP following lower limb muscle injuries via the Delphi process. Consensus was reached on (1) the definitions of \u2018return to training\u2019 and \u2018return to play\u2019 in football. We agreed on \u2018return to training\u2019 and RTP in football, the appropriate use of clinical and imaging assessments, and laboratory and field tests for return to training following lower limb muscle injury, and identified objective criteria for RTP based on global positioning system technology. Level of evidence IV, grade of recommendation D

Factors influencing perception of effort (session rating of perceived exertion) during elite soccer training

Purpose: The aim of the current study was to identify the external-training-load markers that are most influential on session rating of perceived exertion (RPE) of training load (RPE-TL) during elite soccer training. Methods: Twenty-two elite players competing in the English Premier League were monitored. Training-load data (RPE and 10-Hz GPS integrated with a 100-Hz accelerometer) were collected during 1892 individual training sessions over an entire in-season competitive period. Expert knowledge and a collinearity r &lt; .5 were used initially to select the external training variables for the final analysis. A multivariate-adjusted within-subjects model was employed to quantify the correlations of RPE and RPE-TL (RPE × duration) with various measures of external training intensity and training load. Results: Total high-speed-running (HSR; &gt;14.4 km/h) distance and number of impacts and accelerations &gt;3 m/s2 remained in the final multivariate model (P &lt; .001). The adjusted correlations with RPE were r = .14, r = .09, and r = .25 for HSR, impacts, and accelerations, respectively. For RPE-TL, the correlations were r = .11, r = .45, and r = .37, respectively. Conclusions: The external-load measures that were found to be moderately predictive of RPE-TL in soccer training were HSR distance and the number of impacts and accelerations. These findings provide new evidence to support the use of RPE-TL as a global measure of training load in elite soccer. Furthermore, understanding the influence of characteristics affecting RPE-TL may help coaches and practitioners enhance training prescription and athlete monitoring.</p

Bioimpedance Vector References Need to Be Period&#8208; Specific for Assessing Body Composition and Cellular Health in Elite Soccer Players: A Brief Report

none9noPurpose: Bioimpedance data through bioimpedance vector analysis (BIVA) is used to evaluate cellular function and body fluid content. This study aimed to (i) identify whether BIVA patters differ according to the competitive period and (ii) provide specific references for assessing bioelectric properties at the start of the season in male elite soccer players. Methods: The study included 131 male soccer players (age: 25.1 ± 4.7 yr, height: 183.4 ± 6.1 cm, weight: 79.3 ± 6.6) registered in the first Italian soccer division (Serie A). Bioimpedance analysis was performed just before the start of the competitive season and BIVA was applied. In order to verify the need for period-specific references, bioelectrical values measured at the start of the season were compared to the reference values for the male elite soccer player population. Results: The results of the two-sample Hotelling T2tests showed that in the bivariate interpretation of the raw bioimpedance parameters (resistance (R) and reactance (Xc)) the bioelectric properties significantly (T2= 15.3, F = 7.6, p ≤ 0.001, Mahalanobis D = 0.45) differ between the two phases of the competition analyzed. In particular, the mean impedance vector is more displaced to the left into the R-Xc graph at the beginning of the season than in the first half of the championship. Conclusions: For an accurate evaluation of body composition and cellular health, the tolerance ellipses displayed by BIVA approach into the R-Xc graph must be period-specific. This study provides new specific tolerance ellipses (R/H: 246 ± 32.1, Xc/H: 34.3 ± 5.1, r: 0.7) for performing BIVA at the beginning of the competitive season in male elite soccer players.openBongiovanni T.; Mascherini G.; Genovesi F.; Pasta G.; Iaia F.M.; Trecroci A.; Ventimiglia M.; Alberti G.; Campa F.Bongiovanni T.; Mascherini G.; Genovesi F.; Pasta G.; Iaia F.M.; Trecroci A.; Ventimiglia M.; Alberti G.; Campa F

Nutritional interventions for reducing the signs and symptoms of exercise-induced muscle damage and accelerate recovery in athletes: current knowledge, practical application and future perspectives

Purpose This review provides an overview of the current knowledge of the nutritional strategies to treat the signs and symptoms related to EIMD. These strategies have been organized into the following sections based upon the quality and quantity of the scientific support available: (1) interventions with a good level of evidence; (2) interventions with some evidence and require more research; and (3) potential nutritional interventions with little to-no-evidence to support efficacy. Method Pubmed, EMBASE, Scopus and Web of Science were used. The search terms ‘EIMD’ and ‘exercise-induced muscle damage’ were individually concatenated with ‘supplementation’, ‘athletes’, ‘recovery’, ‘adaptation’, ‘nutritional strategies’, hormesis’. Result Supplementation with tart cherries, beetroot, pomegranate, creatine monohydrate and vitamin D appear to provide a prophylactic effect in reducing EIMD. β-hydroxy β-methylbutyrate, and the ingestion of protein, BCAA and milk could represent promising strategies to manage EIMD. Other nutritional interventions were identified but offered limited effect in the treatment of EIMD; however, inconsistencies in the dose and frequency of interventions might account for the lack of consensus regarding their efficacy. Conclusion There are clearly varying levels of evidence and practitioners should be mindful to refer to this evidence-base when prescribing to clients and athletes. One concern is the potential for these interventions to interfere with the exercise-recovery-adaptation continuum. Whilst there is no evidence that these interventions will blunt adaptation, it seems pragmatic to use a periodised approach to administering these strategies until data are in place to provide and evidence base on any interference effect on adaptation

Central and Peripheral Thermal Signatures of Brain-Derived Fatigue during Unilateral Resistance Exercise: A Preliminary Study

Infrared thermography (IRT) allows to evaluate the psychophysiological state associated with emotions from facial temperature modulations. As fatigue is a brain-derived emotion, it is possible to hypothesize that facial temperature could provide information regarding the fatigue related to exercise. The aim of this study was to investigate the capability of IRT to assess the central and peripheral physiological effect of fatigue by measuring facial skin and muscle temperature modulations in response to a unilateral knee extension exercise until exhaustion. Rate of perceived exertion (RPE) was recorded at the end of the exercise. Both time- ( 06TROI: pre\u2013post exercise temperature variation) and frequency-domain ( 06PSD: pre\u2013post exercise power spectral density variation of specific frequency bands) analyses were performed to extract features from regions of interest (ROIs) positioned on the exercised and nonexercised leg, nose tip, and corrugator. The ANOVA-RM revealed a significant difference between 06TROI (F(1.41,9.81) = 15.14; p = 0.0018), and between 06PSD of myogenic (F(1.34,9.39) = 15.20; p = 0.0021) and neurogenic bands (F(1.75,12.26) = 9.96; p = 0.0034) of different ROIs. Moreover, significant correlations between thermal features and RPE were found. These findings suggest that IRT could assess both peripheral and central responses to physical exercise. Its applicability in monitoring the psychophysiological responses to exercise should be further explored

Slow-Speed Resistance Training Increases Skeletal Muscle Contractile Properties and Power Production Capacity in Elite Futsal Players

The purpose of this study was to explore the effects of slow-speed resistance training with low intensity (SRT) on muscle power output in elite futsal players with respect to traditional resistance training. The authors hypothesized that the muscle deoxygenation during SRT causes early recruitment of fast twitch fibers that would positively affect strength and power performance. Thirty male elite futsal players were recruited and randomly assigned either to SRT group or to traditional resistance training (TRT) group. All players underwent an 8-weeks experimental protocol consisting of 2 training sessions per week at both leg curl and leg extension machines. In the SRT, players lifted 50% of one maximum repetition (1RM) involving 3 s for eccentric and concentric actions. In the TRT, players lifted 80% of 1RM involving 1 s for eccentric and concentric actions. All players were tested twice (pre and post) for sprint and jump performances, maximal isometric voluntary contraction (MVC) and maximal isokinetic peak torque (Peak TQ) and total work (TW) at 60 and 120°/s (on knee extensors and flexors). The two groups presented remarkable differences in the within-group changes for all the variables. SRT exhibited greater improvements in both Peak TQ and TW for knee extensors and flexors at 120°/s. Conversely, TRT showed greater improvements in MVC, and in both Peak TQ and TW for knee extensors and flexors at 60°/s, except for Peak TQ of the knee extensors, where no significant difference was found between TRT and SRT. Countermovement jump showed a decrease in eccentric time and an increase in concentric force in SRT group. SRT and TRT resulted effective to enhance the strength performance indices during the 8-weeks experimental protocol. Peak torque at 120°/s explained more of the contractile characteristic effects of SRT training than MVC, suggesting that slow-speed training can cause fast twitch fibers hypertrophy in elite athletes. Since slow-speed training is supposed to produce a decreased exercise-induced muscle damage, SRT method is a suitable option in strength training for futsal and team sports