Statistical Regularities in ATM: network properties, trajectory deviations and delays

One of the key enabler to the productivity and efficiency shift foreseen by SESAR will be the business-trajectory concept. The path to a deep understanding of how this new concept impacts on the future SESAR Air Traffic Management scenario goes through a better understanding of the actual air traffic network, and this will be done in the present paper by analyzing traffic data within the framework of complex network analysis. In this paper we will consider flights trajectory data from the Data Demand Repository database. In a first investigation, we perform a network study of the air traffic infrastructure starting from the airports and then refining our analysis at the level of navigation points in order to understand what are the main features that may help explaining why some nodes of the network happen to be found in the same community, i.e. cluster. In a second investigation we perform a study at the level of flight trajectories with the aim of identify statistical regularities in the spatio-temporal deviations of flights between their planned and actual 4D trajectories

Manipulating Resistance Exercise Variables to Improve Jumps, Sprints, and Changes of Direction in Soccer: What We Know and What We Don’t Know

The present review summarizes the effects of manipulating different resistance exercise variables on jumps, sprints, and changes of direction (CODs) in soccer. Regarding jumps, moderate-to-high loads, full range of movement (ROM), non-failure sets, and a moderate training volume are recommended. Different external resistances like constant-load, flywheel, or elastic bands, as well as various movement velocities and select exercises, are equally effective. As for sprints, moderate-to-high loads, constant load or flywheel but not elastic resistances, movements performed at full ROM, non-failure sets, and moderate-to-high training volume might be more effective, while numerous movement velocities and exercises could be chosen. As for CODs, moderate-to-high loads, flywheel more than constant-load resistance, and a moderate-to-high total number of repetitions are recommended, while several movement velocities and exercises could be selected, though ROM needs investigation. The effectiveness of concentric-only vs. eccentric-only training on jumps, sprints, and CODs has not been investigated, while an external focus and inter-set rest > 2 min are theoretically preferable, albeit not proven. Importantly, high movement velocity is not a prerogative of effectiveness, and limited ROM is not associated with sport-specific patterns such as jumps. Practitioners in soccer may manipulate resistance exercise variables depending on the purpose

Manipulating Resistance Exercise Variables to Improve Jumps, Sprints, and Changes of Direction in Soccer: What We Know and What We Don’t Know

The present review summarizes the effects of manipulating different resistance exercise variables on jumps, sprints, and changes of direction (CODs) in soccer. Regarding jumps, moderate-to-high loads, full range of movement (ROM), non-failure sets, and a moderate training volume are recommended. Different external resistances like constant- load, flywheel, or elastic bands, as well as various movement velocities and select exercises, are equally effective. As for sprints, moderate-to-high loads, constant load or flywheel but not elastic resistances, movements performed at full ROM, non-failure sets, and moderate- to-high training volume might be more effective, while numerous movement velocities and exercises could be chosen. As for CODs, moderate-to-high loads, flywheel more than constant-load resistance, and a moderate-to-high total number of repetitions are recommended, while several movement velocities and exercises could be selected, though ROM needs investigation. The effectiveness of concentric-only vs. eccentric-only training on jumps, sprints, and CODs has not been investigated, while an external focus and inter- set rest > 2 min are theoretically preferable, albeit not proven. Importantly, high movement velocity is not a prerogative of effectiveness, and limited ROM is not associated with sport- specific patterns such as jumps. Practitioners in soccer may manipulate resistance exercise variables depending on the purpose

Reliability of internal and external load parameters in 6 a-side and 7 a-side recreational football for health

Sedentariness and related chronic disorders have a massive impact on healthcare costs worldwide. Contrariwise to endurance-based activities, there are little information and evidence on recreational football amongst middle-aged healthy males. The aim of this study was to assess the reliability of internal and external load parameters during 6 a-side and 7 a-side recreational football formats. 20 subjects were enrolled (mean ± SDs; age = 37 ± 5 years, weight = 77 ± 12 kg, and height = 175 ± 10 cm). Participants completed a match (55 min) and replicated the same match (55 min) a week later. The football matches took place on an artificial grass outdoor field (pitch size of 40 × 25 m). The analysis performed using GPS considered several internal and external load parameters: heart rate (HR), total distance (TD), high speed running (HSR), number of accelerations (> 2 m s−2), and metabolic power (MT). We found good scores of reliability in several parameters in both 6 and 7 a-side, respectively: mean HR (ICC = 0.66 and 0.76), TD (ICC = 0.82 and 0.68, respectively), accelerations (ICC = 0.65 and 0.69, respectively), MT (ICC = 0.76 and 0.83), HSR (ICC = 0.79 and 0.78), and HMD (ICC = 0.80 and 0.78). This study revealed good/excellent scores of absolute reliability, a small mean of change, and small/trivial effect size for internal and external load parameters during the replication analysis of the football formats. Therefore, this study showed that 6 a-side and 7 a-sides are reliable recreational football formats (inter-day reliability). This new evidence can be utilised in the design of football protocols for health

Comparative effects of game profile-based training (GPBT) and small-sided games on physical performance of elite young soccer players

The present study was designed to investigate and compare the effects of game profile-based (GPBT) and small-sided games (SSGs) training on physical performances of elite youth soccer players during the in-season period. Twenty young soccer players (18.6 ± 0.6) were randomly assigned to either GPBT or SSGs protocols performed twice a week for 8 weeks. The GPBT consisted of 2 sets of 6-10 min of intermittent soccer specific circuits. The SSGs training consisted of 3-5 sets of 5 vs. 5 SSGs played on a 42 x 30 m pitch. Before and after the training program, the following physical performance were assessed: repeated sprint ability (RSA), change of direction (COD), linear sprinting on 10-m and 20-m, jumping (CMJ), and intermittent running (YYIRL1). Significant improvements were found in all the assessed variables following both training interventions (p < 0.05). The GPBT group improved more than the SSGs group in the 10-m and 20-m sprint tests by 2.4% (g = 0.4; small effect) and 4% (g = 0.9; large effect), respectively. Conversely, the SSGs group jumped 4% higher (g = 0.4; small effect) and resulted 6.7% quicker than the GPBT (g = 1.5; large effect) in completing the COD task. These results suggest both GPBT and SSGs to be effective for fitness development among elite young soccer players during the competitive season. More importantly, these two conditioning methodologies may be considered in terms of specificity for selectively improving or maintaining specific soccer fitness-related performances in the latter phase of the season

The effect of a single session of plyometric training per week on fitness parameters in professional female soccer players. A randomized controlled trial

Nonnato, A, Hulton, AT, Brownlee, TE, and Beato, M. The effect of a single session of plyometric training per week on fitness parameters in professional female soccer players. A randomized controlled trial. J Strength Cond Res XX(X): 000–000, 2020—As the interest and popularity of female soccer has increased over the last few decades, there still lacks research conducted with the elite population, specifically ecological training interventions during the competitive season. Therefore, the aim of this study was to compare the effectiveness of 12 weeks (undertaken once a week) of plyometric (PLY) training on physical performance in professional female soccer players during the season. Using a randomized controlled trial design, 16 players were included in the current study (mean 6 SD; age 23 6 4 years, weight 60.3 6 4.9 kg, height 167 6 3.7 cm) and randomized in PLY (n 5 8) and Control groups (CON, n 5 8), respectively. Squat jump (SJ), counter movement jump (CMJ), long jump (LJ), single-leg triple jump distance test (triple jump test), changes of direction 505 test (505-COD), and sprint 10 and 30 m were performed before and after 12 weeks of PLY training. Significant within-group differences were found in triple jump test dominant (p 5 0.031, effect size [ES] 5 moderate) and nondominant limb (p 5 0.021, ES 5 moderate) and sprint 10 m (p 5 0.05, ES 5 large), whereas the CON did not report any positive variation. However, neither group reported significant variation in SJ, CMJ, LJ, 505-COD, and sprint 30 m (underlining the difficulties in obtain meaningful variation in season). These findings have strong practical applications because this study showed for the first time that a single session a week of plyometric training can significantly increase sport-specific fitness parameters in professional female soccer players during the season

Effects of an in-season enhanced-negative vs traditional weight training on change of direction and hamstrings-to-quadriceps ratio in soccer players

Objectives The present study investigated the effects of in-season enhanced-negative training (ENT) vs weight training in change of direction (COD), sprinting and jumping ability, muscle mass and strength in semi-professional soccer players. Material and methods Forty male soccer-players participated in the eight-week, 1d/w intervention consisting of 48 squat repetitions for both ENT using a flywheel device (inertia=0.11 kg·m-2) or weight training (80%1-RM) as control group (CON). Agility T-test, 20+20m shuttle, 10m and 30m sprint, squat jump (SJ) and countermovement jump (CMJ), lean mass, quadriceps and hamstrings strength and the hamstringsto- quadriceps ratio were measured. Results Time on agility T-test and 20+20m shuttle decreased in ENT (effect-size =-1.44, 95% CI -2.24/-0.68 and -0.75, -1.09/-0.42 respectively) but not in CON (-0.33, -0.87/0.19 and -0.13, -0.58/0.32). SJ and CMJ height increased in both ENT (0.71, 0.45/0.97 and 0.65, 0.38/0.93) and CON (0.41, 0.23/0.60 and 0.36, 0.12/0.70). Overall, quadriceps and hamstrings strength increased in both ENT and CON (0.38/0.79), but the hamstrings-to-quadriceps ratio increased in ENT (0.31, 0.22/0.40) but not in CON (0.03, -0.18/0.24). Lean mass increased in both ENT (0.41, 0.26/0.57) and CON (0.29, 0.14/0.44). Conclusions The repeated eccentric actions performed in ENT may have led to improvements in braking ability, a key-point in COD performance. Semi-professional soccer players may benefit from an in-season ENT to enhance CO

Determining the neurotransmitter concentration profile at active synapses

Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission

The Effect of 1600 μg Inhaled Salbutamol Administration on 30 m Sprint Performance Pre and Post a Yo-Yo Intermittent Running Test in Football Players

The purpose of the study was to investigate the effect of inhaling 1600 \u3bcg of salbutamol (SAL) on 30 m sprint before and after the Yo-Yo Intermittent Recovery test. In a randomised cross over single blind study 13 male non-asthmatic, football players volunteered (mean \ub1 SD; age 18.1 \ub1 0.9 years; weight 69.5 \ub1 8.3 kg; height 1.78 \ub1 0.07 m). Participants completed two visits and were randomly assigned to either (SAL) or (PLA) treatment and performed a set of three sprints of 30 m before and after the Yo-Yo Intermittent Recovery Test (Yo-Yo IRT). Best sprint and mean sprint were analysed in addition to the distance covered during the Yo-Yo IRT; rating of perceived exertion and heart rate were collected at the end of each level completed. Repeated measures ANOVA were performed to investigate changes in performance between groups. Following the inhalation of supra-therapeutic salbutamol dose (1600 \u3bcg) neither 30 m sprint time (PLA 4.43 \ub1 0.14 s; SAL 4.44 \ub1 0.15 s, p = 0.76) nor distance covered in the Yo-Yo IRT test reported significant variation between PLA conditions (1660 \ub1 217 m) and SAL (1610 \ub1 229 m, p = 0.16). Moreover, lactate values, heart rate and RPE did not differ significantly between groups. The inhalation of 1600 \u3bcg salbutamol does not enhance 30 m sprint performance in non-fatigued and fatigue conditions. Our findings suggest when football players acutely inhale double the permitted dose of salbutamol, as indicated in the World Anti-Doping Agency List of Prohibited Substances and Methods, they will not experience improvements in sprint or endurance performance

The Effect of 1600 μg Inhaled Salbutamol Administration on 30 m Sprint Performance Pre and Post a Yo-Yo Intermittent Running Test in Football Players

The purpose of the study was to investigate the effect of inhaling 1600 μg of salbutamol (SAL) on 30 m sprint before and after the Yo-Yo Intermittent Recovery test. In a randomised cross over single blind study 13 male non-asthmatic, football players volunteered (mean ± SD; age 18.1 ± 0.9 years; weight 69.5 ± 8.3 kg; height 1.78 ± 0.07 m). Participants completed two visits and were randomly assigned to either (SAL) or (PLA) treatment and performed a set of three sprints of 30 m before and after the Yo-Yo Intermittent Recovery Test (Yo-Yo IRT). Best sprint and mean sprint were analysed in addition to the distance covered during the Yo-Yo IRT; rating of perceived exertion and heart rate were collected at the end of each level completed. Repeated measures ANOVA were performed to investigate changes in performance between groups. Following the inhalation of supra-therapeutic salbutamol dose (1600 μg) neither 30 m sprint time (PLA 4.43 ± 0.14 s; SAL 4.44 ± 0.15 s, p = 0.76) nor distance covered in the Yo-Yo IRT test reported significant variation between PLA conditions (1660 ± 217 m) and SAL (1610 ± 229 m, p = 0.16). Moreover, lactate values, heart rate and RPE did not differ significantly between groups. The inhalation of 1600 μg salbutamol does not enhance 30 m sprint performance in non-fatigued and fatigue conditions. Our findings suggest when football players acutely inhale double the permitted dose of salbutamol, as indicated in the World Anti-Doping Agency List of Prohibited Substances and Methods, they will not experience improvements in sprint or endurance performance