What do football coaches want from sport science?

Sport science can contribute to the body of knowledge that influences practice and performance. Despite this, knowledge transfer from sport science to football coaches needs further improvement. The present study’s purpose is to gain insight in current sport science needs and perceived barriers among professional football coaches. A 20 questions digital survey was sent to a database of professional football coaches. Answering options were: check boxes, open fields, and 5-point Likert scales. 75 football coaches (mean ± SD age: 50.0±10.1 years) completed the survey. Coaches had 24.3±7.0 years of experience as a player and 25.5±13.7 years as a coach, and five had a university degree. The coaches evaluated their technical and tactical knowledge as good. Knowledge on physical skills was rated slightly lower and knowledge on mental skills lowest, but still fair. Top five of domains that the coaches wanted to know more were Mental skills, Physical skills, Group dynamics, Monitoring load and capacity, and Talent development. The top 5 perceived barriers for using sport science in daily football practice was Conservatism in clubs, Lack of money, Lack of specific football knowledge of scientists, Poor applicability of sports science in practice, and Lack of time. Personal contact with sport scientists was most preferred to gain knowledge in sport science. Results suggest that there is an interest in applying sport scientific knowledge into football practice. An overview of coaches’ sport science knowledge gaps and perceived implementation barriers could improve the integration of sport science and practical knowledge in work environments

Evidence of widespread mechanical hyperalgesia but not exercise induced analgesia in athletes with mild patellar tendinopathy compared to pain-free matched controls:a blinded exploratory study

OBJECTIVE: To assess centrally induced pain processing with pressure pain thresholds (PPT) bilaterally and remotely in active volleyball and basketball athletes with mild patellar tendinopathy compared to asymptomatic control athletes. Secondary objective was to explore the role of exercised induced analgesia during a training session in athletes with patellar tendinopathy. DESIGN: In this exploratory study, PPTs of 21 patellar tendinopathy athletes and 16 age and sex matched asymptomatic team members were measured by a blinded assessor bilaterally on the patellar tendon and unilaterally on the elbow extensor tendon with a pressure algometer before, during and after a regular training session. RESULTS: Patellar tendinopathy athletes had a significantly higher average body mass index compared to asymptomatic athletes (mean difference 1.75 (95%CI 0.35, 3.15), p= 0.02). At baseline, athletes with patellar tendinopathy showed lowered PPTs in the affected knee (p=0.001), unaffected knee (p<0.001), and elbow (p=0.01) compared to controls. No clear patterns were identified to explain between group differences in PPTs before, during and after exercise. CONCLUSION: This exploratory study found primary and secondary mechanical hyperalgesia in athletes with patellar tendinopathy compared asymptomatic athletes. Further research is required on the effects of an acute exercise bout on pain thresholds in this population

Resonant Inelastic X-ray Scattering Studies of Elementary Excitations

In the past decade, Resonant Inelastic X-ray Scattering (RIXS) has made remarkable progress as a spectroscopic technique. This is a direct result of the availability of high-brilliance synchrotron X-ray radiation sources and of advanced photon detection instrumentation. The technique's unique capability to probe elementary excitations in complex materials by measuring their energy-, momentum-, and polarization-dependence has brought RIXS to the forefront of experimental photon science. We review both the experimental and theoretical RIXS investigations of the past decade, focusing on those determining the low-energy charge, spin, orbital and lattice excitations of solids. We present the fundamentals of RIXS as an experimental method and then review the theoretical state of affairs, its recent developments and discuss the different (approximate) methods to compute the dynamical RIXS response. The last decade's body of experimental RIXS data and its interpretation is surveyed, with an emphasis on RIXS studies of correlated electron systems, especially transition metal compounds. Finally, we discuss the promise that RIXS holds for the near future, particularly in view of the advent of x-ray laser photon sources.Comment: Review, 67 pages, 44 figure

Load Monitoring Practice in Elite Women Association Football

The description of current load monitoring practices may serve to highlight developmental needs for both the training ground, academia and related industries. While previous studies described these practices in elite men's football, no study has provided an overview of load monitoring practices in elite women's football. Given the clear organizational differences (i.e., professionalization and infrastructure) between men's and women's clubs, making inferences based on men's data is not appropriate. Therefore, this study aims to provide a first overview of the current load monitoring practices in elite women's football. Twenty-two elite European women's football clubs participated in a closed online survey (40% response rate). The survey consisted of 33 questions using multiple choice or Likert scales. The questions covered three topics; type of data collected and collection purpose, analysis methods, and staff member involvement. All 22 clubs collected data related to different load monitoring purposes, with 18 (82%), 21 (95%), and 22 (100%) clubs collecting external load, internal load, and training outcome data, respectively. Most respondents indicated that their club use training models and take into account multiple indicators to analyse and interpret the data. While sports-science staff members were most involved in the monitoring process, coaching, and sports-medicine staff members also contributed to the discussion of the data. Overall, the results of this study show that most elite women's clubs apply load monitoring practices extensively. Despite the organizational challenges compared to men's football, these observations indicate that women's clubs have a vested interest in load monitoring. We hope these findings encourage future developments within women's football

Quantifying change of direction load using positional data from small-sided games in soccer

PURPOSE: Quantifying change of direction (COD) load through positional data from small-sided games (SSG) and assess its criterion and construct validity. METHODS: Elite male youth soccer players (n = 25, 16.8 ± 1.3 years) played three SSG (5v5, 5×4 min) with different field dimensions (small [40×30 m], medium [55×38 m], large [70×45 m]). Positional data of the players was obtained with a Local Position Measurement system. COD load (AU) was quantified based on the combination of velocity and change in heading direction. Additionally, total distance covered, running distance, acceleration count, deceleration count, and Rating of Perceived Exertion were measured. Criterion validity was assessed by correlating COD load and the load indicators. Construct validity was determined by testing the differences between the SSG field dimensions. RESULTS: Strong correlations were determined between COD load and total distance covered (r = 0.74, p < .01) and running distance (r = 0.84, p < .01). Middle and large field size resulted in highest COD load (p < .05). CONCLUSION: These results suggest that the COD load measure shows sufficient criterion and construct validity

Load Monitoring Practice in European Elite Football and the Impact of Club Culture and Financial Resources

Load monitoring is considered important to manage the physical training process in team sports such as Association Football. Previous studies have described the load monitoring practices of elite English football clubs and clubs with an established sports-science department. An examination of a broader international sample is currently not available. In addition, previous research has suggested factors that may improve the implementation of load monitoring practices, such as a strong club belief on the benefit of evidence-based practice (EBP) and high club financial resources. However, no study has examined yet the actual impact of these factors on the monitoring practices. Therefore, this study aims (1) to provide an overview of load monitoring practices in European elite football and (2) to provide insight into the differences in implementation between clubs by examining the impact of the club beliefs on the benefit of EBP and the club financial resources. An online survey, consisting of multiple choice and Likert scale questions, was distributed among sports-science and sports-medicine staff (n = 99, 50% response rate). Information was asked about the types of data collected, collection purposes, analysis methods, and staff involvement. The results indicated that external load data (e.g., global navigation satellite system, accelerometer…) was collected the most whilst respondents also indicated to collect internal load (e.g., heart rate, rating of perceived exertion…) and training outcome data (e.g., aerobic fitness, neuromuscular fatigue…) for multiple purposes. Considerable diversity in data analysis was observed suggesting that analysis is often limited to reporting the gathered data. Sports-science staff were responsible for data collection and analysis. Other staff were involved in data discussion to share decision-making. These practices were positively impacted by a stronger club belief on the benefit of EBP and greater financial resources. Creating an organizational culture, characterized by a strong belief on the benefit of EBP, is important to increase the impact of load monitoring. However, the actual potential may still be largely determined by financial resources. High-level clubs could therefore play a leading role in generating and sharing knowledge to improve training practices and player health

External load differences between elite youth and professional football players:ready for take-off?

This study examines differences in weekly load between the first (FT) and the under 19 team (U19) within a professional football setting. Data were collected in 11 FT and 9 U19 players (2016-2017 season). FT data was divided into weeks with (FT-M1) or without (FT-M0) a mid-week match. Indicators were total distance (TD) and TD at 12-15, 15-20, 20-25 and >25 km‧h-1 and were analysed as external load (m), intensity (m‧min-1) and load monotony (a.u.). TD-based load was higher for U19 compared to FT-M0 (very likely moderate) and FT-M1 (likely large). Differences at higher velocities were substantially less (trivial to possibly small), with TD >25 km‧h-1 being lower than FT-M0 (very likely moderate) and FT-M1 (likely small). All intensity indicators were lower for U19 (likely small to almost certainly large). Load monotony was higher compared to FT-M1 (possibly small to almost certainly very large). Compared to FT-M0, monotony was higher for TD (possibly very large) and TD >25 km‧h‑1 (possibly moderate) but lower for TD 12-15 (possibly small) and 15-20 km‧h‑1 (likely moderate). So, despite higher weekly external loads at low velocity for elite youth players, external intensity and load variation increases when these players may transition to professional football.