Mind the gap! A survey comparing current strength training methods used in men’s versus women’s first team and academy soccer

Much less is known about strength and conditioning (S&C) practice in women's versus men's soccer. The aim of this study was to compare S&C practice between coaches working in men's or women's soccer, at first team or academy level, worldwide. A total of 170 participants, who were involved with S&C support at their soccer club (in Europe, USA and South America, within men's or women's first team or academy settings) completed a comprehensive online survey, designed to evaluate (i) their academic qualifications and S&C coaching experience; and their preferred methods for (ii) physical testing; (iii) strength and power development; (iv) plyometric training; (v) speed development; and (vi) periodization. Women's academies had fewer weekly in-season S&C sessions than men's academies (1.6±0.6 vs. 2.3±0.9, p=0.005). Relatively, fewer women's academy S&C coaches (6%) used Olympic weightlifting movements than men's academy S&C coaches (32%, p=0.030). Relatively, more women's academy coaches (47%) used the Nordic hamstring exercise (NHE) compared to men's academy coaches (15%, p=0.006), but relatively more women's vs. men's first team coaches (61% vs. 38%, p=0.028) and women's vs. men's academy (61% vs. 38% coaches, p=0.049) utilised rating of perceived exertion-based load prescriptions. Notable differences in S&C practice exist between coaches of men's and women's soccer squads, particularly at academy level. Fewer weekly S&C sessions in women academy players may have implications for physical development, while the greater use of subjective load prescriptions in both academy and first team women's squads may lead to sub-optimal performance gains

Physical testing and strength and conditioning practices differ between coaches working in academy and first team soccer

Scientific guidelines exist regarding strength and conditioning (S&C) best practice, for both first team and academy level soccer. However, it is not known if these research-informed guidelines are followed in such applied settings. The aim of this study was to investigate current S&C practice in first team and academy level (men's and women's) soccer, in multiple countries/continents. A total of 170 participants, who were involved with the delivery of S&C support at their soccer club, completed a comprehensive survey, describing their training methods. Data were analysed using Pearson's chi-square test of independence and independent t-tests. Statistical significance was set to p < 0.05. A greater proportion of academy compared to first team coaches assessed acceleration/sprint (92% vs. 83%, p=0.026), jump (95% vs. 83%, p=0.023) and change of direction performance (77% vs. 61%, p=0.031). The weekly training structure differed between groups, particularly within women's squads, with women's academy coaches reporting the lowest session frequency of all groups (1.59 ± 0.62 session per week, 44 ± 17 min duration). A greater proportion of academy (54%) versus first team (35%) coaches prioritised bodyweight training (p=0.031), despite a similar distribution of movement patterns trained. Overall, 44% S&C coaches reported using training intensities below strength training guidelines (≥80% 1RM). To conclude, there were many differences in S&C practice between S&C coaches working with first team and academy squads but particularly noteworthy was the greater proportion of academy coaches prioritising bodyweight training compared to first team coaches, which may limit physical development in academy players

Dust Flux Monitor Instrument measurements during Stardust-NExT Flyby of Comet 9P/Tempel 1

The Dust Flux Monitor Instrument (DFMI) on the Stardust and Stardust-NExT missions measured impacts from coma dust particles with masses from ∼10−15 to >10−6 kg using two kinds of sensors – one based on polyvinylidene fluoride (PVDF) thin films and the other on acoustic detectors (ACs) mounted on the front and second layers of the Whipple Bumper Shield. At the higher encounter speed of 10.9 km s−1 at Comet 9P/Tempel 1 compared with 6.12 km s−1 at 81P/Wild 2 encounter, the mass sensitivity of DFMI sensors increased by between a factor of 2 and 12 (depending on the sensor subsystem), but the spatial resolution (⩾1.09 km) decreased to approximately a half. The coma of Comet Tempel 1 exhibits highly non-uniform spatial distribution of dust, as found at comet Wild 2, with bursts of impacts of up to 1000 particles over km scales near closest approach surrounded by void regions of many kilometers with no impacts. These data are consistent with passage through clouds of particles resulting from fragmentation of larger aggregates emitted from the nucleus. These fragmentation products dominate the total dust production of small particles, with only a small contribution likely from direct emission from the nucleus. The derived overall mass distribution is similar to that found at comet Wild 2 with the total mass dominated by large particles. The average cumulative mass index α = 0.65 ± 0.08 (where the particle flux is defined by ϕ (>m) = km−α) but a better fit is obtained with α = 0.85 ± 0.08 for particle masses below 10−10 kg and a significantly lower value for higher masses

Global differences in current strength and conditioning practice within soccer

Differences exist between top-tier soccer leagues (e.g. anthropometry and match demands), which may influence strength and conditioning (S&C) practice. Thus, the aim of this study was to investigate whether current S&C practice in men's and women's (first team and academy) squads differed between global regions. A total of 170 participants, involved in the delivery of S&C support at their soccer club (based on South America (SA), the USA, the UK, or other European countries (EUR)), completed a survey examining their S&C methods. The survey comprised six sections: (i) academic qualifications and S&C coaching experience; and their preferred methods for (ii) physical testing; (iii) strength and power development; (iv) plyometric training; (v) speed development; and (vi) periodization. Coaches in EUR conducted fewer formal S&C sessions, placed less importance on free-weight resistance training (RT), and performed less speed and plyometric training compared to coaches in other global regions (all p<0.05). While coaches working with UK squads devoted more time to physical development than those in EUR, they regarded bodyweight training as the most important RT modality in comparison to USA and SA, who prioritized free-weight RT. Finally, SA academy players are introduced to formal S&C later (14 years old) than those in the UK (12 years old, p=0.002). However, it is reasonable to suggest that the S&C practice of coaches in the USA and SA align better with scientific guidelines for strength and power development in soccer, with emphasis on free-weight RT alongside regular sprint and plyometric training, compared to coaches in the UK and EUR

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Assiniboine Credit Union. Manitoba Research Alliance. Neighbourhoods Alive!. The Social Sciences and Humanities Research Council of Canada. United Way Winnipeg

The dust mass distribution of comet 81P/Wild 2

The Dust Flux Monitor Instrument (DFMI) made direct measurements of the dust environment in the mass range 10-14 m -5 kg at comet 81P/Wild 2 during the Stardust flyby on 2 January 2004. We describe the techniques for derivation of the particle mass distribution, including updated calibration for the acoustic subsystem. The dust coma is characterized by "swarms" and "bursts" of particles with large variations of flux on small spatial scales, which may be explained by jets and fragmentation. The mass of the dust coma is dominated by larger particles, as was found for comets 1P/Halley and 26P/Grigg-Skjellerup. However, almost 80% of the particles were detected many minutes after closest approach at a distance of ~4000 km, where small grains dominated the detected mass flux. The mass distribution varies on small spatial scales with location in the coma, consistent with the jets and fragmentation inferred from the highly heterogeneous dust spatial distribution. The cumulative mass distribution index α (where the number of particles of mass m or larger, N(m) α m -α) in the coma ranges from 0.3 to 1.1. It is possible that jets and fragmentation occur in all comets but have not previously been well observed due to the limitations of detectors and flyby geometry. We estimate that 2800 ± 500 particles of diameter 15 μm or larger impacted the aerogel collectors, the largest being ~6— 10-7 kg (diameter ~1 mm), which dominates the total collected mass. Of these, only 500 ± 200, representing just 3% of the collected mass, originated in the far postencounter region

Near-Earth asteroid sample return missions

The rate of discovery of new NEAs and the success of D-S 1 and NEAR-Shoemaker, suggest that sample return from NEAs is now technically feasible. Here we present a summary of a recent workshop on the topic

Free-weight Resistance Training in Youth Athletes: A Narrative Review

Generating high levels of muscular strength and power are important for success in sport and may have long-term implications for sporting careers in youth athletes. Importantly, maturation may confound the neuromuscular adaptations to resistance training when attempting to differentiate between training- vs. growth-induced strength and power gains; thus, potentially leading to erroneous conclusions regarding the efficacy of resistance training in youth athletes. The aim of this review was to critically appraise the literature concerning the efficacy of externally loaded free-weight resistance training on strength and power measures in youth athletes at different stages of maturity. Strength underpins power production; thus, developing strength through traditional resistance training methods can positively influence powerful sporting movements. In addition, weightlifting has the capacity to improve muscular power via explosive low-body triple extension, which is essential for many sports. Despite the complexity of the techniques involved, it can be a safe and effective method to improve athletic qualities in young athletes, potentially more so than plyometric training. Whereas, low-load, high-velocity training can have a positive influence on high-speed movements, such as sprinting, but the lack of high-intensity appears to be disadvantageous post peak-height velocity. Irrespective of age, well-coached progressive strength training adhering strictly to correct technique can then be periodised within a long-term athletic development program. It is important to primarily develop muscular strength, while concurrently refining the technical skill required for weightlifting. Physically mature athletes should undertake high-intensity resistance training to maximise neuromuscular adaptations, leading to positive changes in strength and power