Castagna, C, Lorenzo, F, Krustrup, P, Fernandes-da-Silva, J, Póvoas, SCA, Bernardini, A, and D'Ottavio, S. Reliability characteristics and applicability of a repeated sprint ability test in young male soccer players. J Strength Cond Res 32(6): 1538-1544, 2018-The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30 m interspersed with 30 seconds of active recovery in nonelite, outfield, young, male soccer players. Twenty-six (age, 14.9 ± 1.2 years; height, 1.72 ± 0.12 cm; body mass, 62.2 ± 5.1 kg) players were tested 48 hours and 7 days apart for 5 × 30-m performance over 5 trials (T1-T5). Short-term (T1-T2) and long-term (T1-T3-T4-T5) reliabilities were assessed with intraclass correlation coefficient (ICC) and with typical error for measurement (TEM). Short- and long-term reliability ICCs and TEMs for total sprint time and best sprint performance were nearly perfect and satisfactory, respectively. Usefulness (as smallest worthwhile change and TEM ratio) resulted acceptable (i.e., = 1) and good (i.e., >1) for total sprint time and best sprint performance, respectively. The present study revealed that the 5 × 30-m sprint test is a reliable field test in short and long terms when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials.

The aim of the study was to examine the associations between maximal and submaximal field tests with match physical activity and biological maturation in youth football players. Sixty-eight youth football players (U14, U15, U16, U17) performed maximal and submaximal field endurance tests. Biological maturity was estimated calculating the distance from peak height velocity (Y-PHV). Physical match activities were tracked using GPS units and players’ post-match rate of perceived exertion (RPE) was recorded. Mainly moderate associations were found between field tests and match activities. Large correlations were found between Yo-Yo Intermittent Recovery test level 1, distance covered at high and very high-speed running, the quantity of very high and maximal metabolic power running. Small to moderate associations between match activities and Y-PHV were observed. The magnitude of correlation between match activities and field tests increased from moderate to large when matches with an RPE>5 were considered. The results provide further evidence of the association between young football players’ aerobic performance and match work rate. Submaximal field tests demonstrate ecological validity and may constitute a practical alternative to performing maximal tests. Maturation was found to have a moderate effect on youth players’ match work rate.

The results of this study showed the superiority of generic over specific drills in inducing LSA-related physiological responses. In this regard production RDs showed the higher postexercise BL. Individual peak blood lactate responses were found after the NMT 30-s all-out test, suggesting this drill as a valid option to RDs. The practical physiological diversity among the generic and specific LSA drills here considered enable fitness trainers to modulate prescription of RD and SSG drills for LSA according to training schedule.

Regular physical exercise plays a role in improving cardiovascular and muscular fitness in many metabolic diseases. This study aims to verify any possible benefits, including the eventual influence on any associated risk factors, in a group of kidney transplant recipients after a short period of personalized training programs with mixed exercises. In January 2013, at the Sports Medicine Center of the University of Florence, Italy, we began studying a group of 20 kidney transplant recipients. After 6 months of exercise, they underwent Cardiopulmonary Test (CPET), ECG, skin fold, bioimpedance analysis and stress test for the lower and upper limbs. EF increased significantly from 63.38 ± 4 to 67.30 ± 5.9 with p < 0.05; the anaerobic threshold improved from 14.48 ± 6.3 to 20.24 ± 3.7 (p < 0.05) with good stress tolerance, estimated by CR10 scale; weight decreased significantly (70.06-65.03 kg) as did skin folds at pectoral level (p < 0.002). Upper limb muscular strength increased significantly (p < 0.005). Regular mixed exercise is a proposed program in post-transplant syndrome with the expectation of improving cardiovascular performance and enhancing exercise tolerance. Muscle strength improves with physical fitness with consequent reduction of risk factors linked to visceral fat. Proof of an eventual positive impact on other complex aspects associated with post-transplant metabolic syndrome will require a longer follow-up.

Soccer is a sport team with a discontinuous nature of physical effort and the duration of the regular season is 10 months length. Hydration status, water consumption are aspects of human performance debate in recent years and it's well demonstrated as a reduction of total body water impairs endurance ability. Bio impedance is a useful methods to assess total body water, in addition recent studies reports a new approach in the evaluation of hydration status independently from body weight. The aim of the study was to determine changes of the bioelectrical impedance throughout a soccer season. Bioelectrical parameters of a Italian professional football team were recorded eight time during a regular season. The detection were carried out following the standard tetra polar method. Twenty-five male soccer players were submitted at BIA measurement, but only eleven athletes took part in all eight sessions detection. The data recorded by conventional BIA processing didn't show any statistical differences in weight, hydration and cellular masses. Bio Impedance Vector Analysis (BIVA) shows a high significance in Anova test for the values of Xc (p<0.01) and PA (p<0.001), no difference in Rz among eight measurements. Body composition and hydration status in footballers are generally well and the variations in conventional BIA are minimal. Therefore BIVA in this population may give specific information for physiological changes for training dues. A regular bio impedance assessment in athletes is desirable to follow adaptations to training loads.