Purpose: The aim of the present study was to examine the variation in physical activity of elite soccer players within successive prolonged periods of fixture congestion over 5 months of competition during the competitive season 2011-2012. ), and maximal (>27 km.h -1 ) intensity running (IR) were measured and analysed using a semi-automatic match analysis system (Amisco Pro™). MethodsResults: No differences were observed between congested and non-congested periods (two vs. one match a week, respectively) for the total distance covered at all the speed thresholds over 18 km.h -1 , with no variation in physical fitness over the 5 studied months. Specifically to the playing positions, regardless of the congestion periods, FB and WM covered more distance than CDM over 21km.h -1 ; FB, WM and FW covered similar distances for all running intensities; and CD and CDM covered shorter distance during non-congested compared to congested periods (P<0.05) at light-IR. Conclusion:The present study reveals that prolonged congested match fixture did not affect the high-intensity physical activity of top-class soccer players during official games during a 5 months fixture period.

Highlights We found that, in a hot environment, physical workload (in terms of energy expenditure) of rebar work is: overall rebar work (2.57Kcal/min), bar bending (2.26Kcal/min) and bar fixing (2.67Kcal/min). Bar fixing induced significantly higher physiological responses in heart rate, percentage of maximal heart rate, oxygen consumption, energy expenditure as compared to bar bending. Perceptual response was also higher in bar fixing as compared to bar bending, but such difference was not statistically significant. oxygen consumption (9.53 vs. 7.14 ml/min/kg, p < 0.05), and energy expenditure (2.67 vs.2.26 Kcal/min, p < 0.05) (186 vs. 158 W, p < 0.05) as compared to bar bending. Perceptual response was higher in bar fixing but such difference was not statistically significant.Findings of this study enable the calculation of daily energy expenditure of rebar work.

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The purposes of this study were to provide information about the physiological characteristics of Asian elite youth soccer players (a) for strength and conditioning specialists to design training program based on players' physiological characteristics and b) for coach to design an appropriate play tactic. Sixteen Chinese elite youth male players (height: 173 +/- 5.2 cm; weight: 64.2 +/- 8.1 kg; and age: 16.2 +/- 0.6 years) from the U-17 national team participated in the following tests in the current study: (a) maximal vertical jump, (b) isokinetic muscular strength tests of knee joint at angular velocities of 60, 120, 180, 240, and 300 degrees x s, (c) maximal oxygen consumption (VO2max), (d) 1 repetition maximum (1RM) strength test, and (e) 30-m sprint. Compared with European and African players, Asian youth players have less jump height and shorter body height. They also have poor performance in isokinetic muscular strength of quadriceps and hamstrings (especially at high speed), VO2max, 1RM strength test, sprint starts, and 20- to 30-m sprints. A specialized training in jumping performance, high-speed movement, muscular strength at high contraction speed, endurance running, short distance sprint (i.e., 5 m), and 20- to 30-m sprints are recommended for Asian elite youth soccer players (or players with similar physique and ability).

Purpose: The study aimed to compare the physiological and perceptual responses of two high intensity intermittent aerobic exercises (HIIE), i.e. the 15s/15s exercise and an exercise on the Hoff track (HTE). Methods:In this within-subject repeated measures study, seven high-level soccer players (Age: 24.1± 4.5yr; Height: 175± 0.04cm; Body mass: 67.9± 9.0kg; % Body fat: 14.2± 2.4%) performed the two exercises with same total duration (25 minutes) in a randomized order: 1) a 15s/15s protocol at 120% of maximal aerobic speed (MAS), and 2) HTE. Heart rate (HR) and oxygen uptake (VO 2 ) were measured continuously throughout both exercises. The rating of perceived exertion (RPE) was measured 15 min after the end of each exercise. Blood lactate concentration ([La]) was measured at rest before each exercise, between and at the end of each set. Conclusion: Our results demonstrate that VO 2 and [La] were higher during HTE than during the 15s/15s when matched with duration. However, HTE was perceived less intense than 15s/15s. Thus, the use of HTE appears as an effective alternative for fitness coaches to develop aerobic endurance in soccer players. Results: The mean VO

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The aim of this study was to analyse the variance of different competitive leagues, score status, and tactical position in the centrality levels of degree prestige, degree centrality and page rank in football players. A total of 20 matches from the Spanish La Liga League (10 matches) and English Premier League (10 matches) were analysed and codified in this study. In this study only the top four teams and their opponents per each competitive league were analysed. A total of 14,738 passes between teammates were recorded and processed. The multivariate MANOVA revealed statistical differences in centrality among tactical positions (λ = 0.958; F(15,1212) = 37.898; p-value = 0.001; η 2 = 0.319; Moderate Effect Size). Midfielders had the greatest centrality values, followed by the external and central defenders. The lowest values of centrality were found in goalkeepers and forwards. No statistical differences were found in centrality between different competitive leagues (λ = 0.001; F(3,402) = 0.050; p-value = 0.985; η 2 = 0.001; Very Small Effect Size) and score status (λ = 0.003; F(6,806) = 0.175; p-value = 0.983; η 2 = 0.001; Very Small Effect Size).

Cooling treatment is regarded as one of good practices to provide safe training conditions to athletic trainers in the hot environment. The present study aimed to investigate whether wearing a commercial lightweight and portable hybrid cooling vest that combines air ventilation fans with frozen gel packs was an effective means to reduce participants' body heat strain. In this within-subject repeated measures study, 10 male volunteers participated in two heat-stress trials (one with the cooling vest - COOL condition, and another without - CON condition, in a randomized order) inside a climatic chamber with a controlled ambient temperature 33 °C and relative humidity (RH) 75% on an experimental day. Each trial included a progressively incremental running test, followed by a 40 min post-exercise recovery. Core temperature (Tc), heart rate (HR), sweat rate, rating of perceived exertion (RPE), exercise duration, running distance, power output, and sweat rate were measured. When comparing the two conditions, a non-statistically significant moderate cooling effect in rate of increase in Tc (0.03±0.02 °C/min for COOL vs. 0.04±0.02 °C/min for CON, p=0.054, d=0.57), HR (3±1 bpm/min for COOL vs. 4±1 bpm/min for CON, p=0.229, d=0.40), and physiological strain index (PSI) (0.20±0.06 unit/min for COOL vs. 0.23±0.06 unit/min for CON, p=0.072, d=0.50) was found in the COOL condition during exercise. A non-statistically significant (p>0.05) trivial cooling effect (d<0.2) was observed between the COOL and CON conditions for measures of exercise duration, running distance, power output, sweat rate and RPE. It is concluded that the use of the hybrid cooling vest achieved a moderate cooling effect in lowering the rate of increase in physiological strain without impeding the performance of progressively incremental exercise in the heat.