Applied Sports Science newsletter – May 31, 2021

Applied Sports Science news articles, blog posts and research papers for May 31, 2021

 

Roger Federer on Retirement, Wimbledon, and Becoming Switzerland’s New Tourism Ambassador

GQ, Caira Conner from

Roger Federer is many things. He is, defensibly, the greatest male tennis player of all time. He is one of the ten highest-paid athletes in the world (last year, he pulled in $90 million dollars, a few million more than his elder football-playing friend, Tom Brady). He’s about to turn 40. He is 20 years and 20 Grand Slam Championship titles into his career, and he is still someone who, after 18 months of global chaos and devastation—and, for him personally, two knee surgeries and five weeks on crutches—has high hopes: Namely, to win (at least) one more (one last?) Grand Slam.

Oh, and Switzerland. Roger Federer really wants you to come to Switzerland.


As others sit, Dak Prescott believes Cowboys’ offseason work will ‘pay off’

ESPN NFL, Todd Archer from

… As the Cowboys work through phase 3 of the offseason program with their organized team activities and three-day minicamp (June 8-10), things are feeling a bit more normal, with at least in-person practices if not full in-person meetings.

“I’m loving ‘normal,’ there’s no doubt about it,” McCarthy said. “It’s great to be out on the field with your players. It’s a lot of fun to see the coaches and you know how much time they put into the planning of practices, the drill work. … The energy in the building since Monday has kicked off has been on a whole different level. This is what we need. This is what I’ve always felt you did need, especially being a young team, especially being a team that’s new in a lot of phases.”


Isn’t It Time the NHL Protected Stars the Way it Protects Goalies?

The Hockey News on Sports Illustrated, Ken Campbell from

Connor McDavid hasn’t drawn a penalty in the playoffs in the past two years. Yet we continue to see goals that look good get called back because of goalie interference. What gives?


How Does Jet Lag Affect Sleep? Jet lag affects people everywhere. Here’s how you can adjust.

Psychology Today, Michael J Breus from

  • Jet lag is a circadian rhythm disorder that occurs when the body’s internal clock does not match the time zone of where one is traveling.
  • Jet lag can cause symptoms such as daytime fatigue, irritability, and sleep deprivation.
  • Tips for relieving jet lag include adjusting your schedule before traveling, staying hydrated, and light exposure.

  • How Much Sleep Does an Elite Athlete Need?

    International Journal of Sports Physiology and Performance from

    Purpose: Anecdotal reports indicate that many elite athletes are dissatisfied with their sleep, but little is known about their actual sleep requirements. Therefore, the aim of this study was to compare the self-assessed sleep need of elite athletes with an objective measure of their habitual sleep duration. Methods: Participants were 175 elite athletes (n = 30 females), age 22.2 (3.8) years (mean [SD]) from 12 individual and team sports. The athletes answered the question “how many hours of sleep do you need to feel rested?” and they kept a self-report sleep diary and wore a wrist activity monitor for ∼12 nights during a normal phase of training. For each athlete, a sleep deficit index was calculated by subtracting their average sleep duration from their self-assessed sleep need. Results: The athletes needed 8.3 (0.9) hours of sleep to feel rested, their average sleep duration was 6.7 (0.8) hours, and they had a sleep deficit index of 96.0 (60.6) minutes. Only 3% of athletes obtained enough sleep to satisfy their self-assessed sleep need, and 71% of athletes fell short by an hour or more. Specifically, habitual sleep duration was shorter in athletes from individual sports than in athletes from team sports (F1,173 = 13.1, P < .001; d = 0.6, medium), despite their similar sleep need (F1,173 = 1.40, P = .24; d = 0.2, small). Conclusions: The majority of elite athletes obtain substantially less than their self-assessed sleep need. This is a critical finding, given that insufficient sleep may compromise an athlete’s capacity to train effectively and/or compete optimally.


    Bouncing behavior of sub-four minute milers

    Nature Scientific Reports journal from

    Elite middle distance runners present as a unique population in which to explore biomechanical phenomena in relation to running speed, as their training and racing spans a broad spectrum of paces. However, there have been no comprehensive investigations of running mechanics across speeds within this population. Here, we used the spring-mass model of running to explore global mechanical behavior across speeds in these runners. Ten elite-level 1500 m and mile runners (mean 1500 m best: 3:37.3 ± 3.6 s; mile: 3:54.6 ± 3.9 s) and ten highly trained 1500 m and mile runners (mean 1500 m best: 4:07.6 ± 3.7 s; mile: 4:27.4 ± 4.1 s) ran on a treadmill at 10 speeds where temporal measures were recorded. Spatiotemporal and spring-mass characteristics and their corresponding variation were calculated within and across speeds. All spatiotemporal measures changed with speed in both groups, but the changes were less substantial in the elites. The elite runners ran with greater approximated vertical forces (+ 0.16 BW) and steeper impact angles (+ 3.1°) across speeds. Moreover, the elites ran with greater leg and vertical stiffnesses (+ 2.1 kN/m and + 3.6 kN/m) across speeds. Neither group changed leg stiffness with increasing speeds, but both groups increased vertical stiffness (1.6 kN/m per km/h), and the elite runners more so (further + 0.4 kN/m per km/h). The elite runners also demonstrated lower variability in their spatiotemporal behavior across speeds. Together, these findings suggested that elite middle distance runners may have distinct global mechanical patterns across running speeds, where they behave as stiffer, less variable spring-mass systems compared to highly trained, but sub-elite counterparts.


    From Motor Control to Team Play in Simulated Humanoid Football

    arXiv, Computer Science > Artificial Intelligence; Siqi Liu et al. from

    Intelligent behaviour in the physical world exhibits structure at multiple spatial and temporal scales. Although movements are ultimately executed at the level of instantaneous muscle tensions or joint torques, they must be selected to serve goals defined on much longer timescales, and in terms of relations that extend far beyond the body itself, ultimately involving coordination with other agents. Recent research in artificial intelligence has shown the promise of learning-based approaches to the respective problems of complex movement, longer-term planning and multi-agent coordination. However, there is limited research aimed at their integration. We study this problem by training teams of physically simulated humanoid avatars to play football in a realistic virtual environment. We develop a method that combines imitation learning, single- and multi-agent reinforcement learning and population-based training, and makes use of transferable representations of behaviour for decision making at different levels of abstraction. In a sequence of stages, players first learn to control a fully articulated body to perform realistic, human-like movements such as running and turning; they then acquire mid-level football skills such as dribbling and shooting; finally, they develop awareness of others and play as a team, bridging the gap between low-level motor control at a timescale of milliseconds, and coordinated goal-directed behaviour as a team at the timescale of tens of seconds. We investigate the emergence of behaviours at different levels of abstraction, as well as the representations that underlie these behaviours using several analysis techniques, including statistics from real-world sports analytics. Our work constitutes a complete demonstration of integrated decision-making at multiple scales in a physically embodied multi-agent setting. See project video at this https URL.


    A collaborative approach that engages the community to develop digital biomarkers

    Nature Portfolio Health Community, Solveig Sieberts from

    … Inspired by the way brains work, deep learning models with neural networks methods were overwhelmingly more accurate than signal processing-based approaches when we had massive amounts of data (in this case ~40,000 sets of sensor reads). But they performed similarly to signal processing methods when the data size was an order of magnitude smaller. Of course, data sets of sufficient size are incredibly rare and prohibitive to collect for most groups. Democratizing data access can facilitate better biomarker development.

    Access to data is not the only barrier to the development of quality digital biomarkers. In an attempt to publish or perish, researchers’ own self-interests can lead them to use subtle tactics such as selective choice of data and metrics to improve the perception of their model accuracy relative to competing methods. Unfortunately, the peer-review process is often not sufficient to detect these subtle manipulations. This also makes it difficult to truly understand the relative performance of competing methods in a truly unbiased fashion.


    U.S. Open line judges to be replaced by technology this year

    Reuters, Sports from

    Line judges will no longer feature at the U.S. Open after the United States Tennis Association (USTA) said on Monday that it was implementing the use of electronic line calling on all courts at the year’s final Grand Slam.

    Electronic line calling technology was also used at last year’s U.S. Open, apart from at the Arthur Ashe and Louis Armstrong stadiums. The technology was also deployed at the Australian Open, a move largely welcomed by players.


    Google rolls out Health Equity Tracker platform, highlighting disparities between communities

    MobiHealthNews, Mallory Hackett from

    The Satcher Health Leadership Institute at Morehouse School of Medicine today launched its Health Equity Tracker, a data platform that highlights the disparate impacts of COVID-19 on marginalized communities.

    Built with support from Gilead Sciences, Google.org, the Annie E. Casey Foundation and the CDC Foundation, the tracker is a data visualization tool that displays the scale of COVID-19 cases, deaths and hospitalizations across race and ethnicity, sex and age, from a whole-country view down to the county level.

    What’s more, the Health Equity Tracker allows users to view different conditions and determinants that have led to unequal COVID-19 outcomes, including COPD, diabetes, poverty and uninsured rates. It can also be used to compare outcomes in different locations.


    Do players run less in the second half of a game?

    Barca Innovation Hub, Carlos Lago Peñas from

    … A recent publication has analysed the differences in LaLiga’s players physical performance during the first and second half considering the total duration of the game and the effective playing time.8 The study, published in the Journal of Strength and Conditioning Research in 2021, was based on the analysis of the 380 games played during the 2018-19 season. In total, 412 players’ performance who played the entire match was examined, getting 4,249 observations. The players were classified into 5 positional roles: Central Defenders (CD, number of observations = 1,231), External Defenders (ED, number of observations = 915), Central Midfielders (CM, number of observations = 1,013), External Midfielders (EM, number of observations = 512) and Forwards (F, number of observations = 578). Physical performance was analysed considering the following categories: total distance covered, low intensity running (0–14.0 km/h), mid intensity running (14.1–21.0 km/h), high-intensity running (21.1–24.0 km/h) and sprint (> 24.0 km/h). All these variables were calculated taking into account the total playing time and the effective playing time, and they were standardised to meters per minute. Physical performance was measured by the TRACAB tracking system used by Mediacoach.

    The results suggest some very relevant conclusions:

  • (1) The effective playing time in games was 52 minutes and 18 seconds (54.9% of the total time). The effective playing time was significantly lower (p < 0.001) in the second half (25 minutes and 43 seconds, 52.5% of the total time) compared to the first half (26 minutes and 36 seconds, 57.4% of the total time).

  • Analyzing English Premier League VAR Football Decisions

    Towards Data Science, Kenneth Leung from

    Reviewing the controversial implementation of Video Assistant Referees in English football using Python


    “Small steps, or giant leaps?” Comparing game demands of U23, U18, and U16 English academy soccer and their associations with speed and endurance

    International Journal of Sports Science & Coaching from

    The current study aimed to compare locomotive outputs across English U16, U18 and U23 academy soccer and investigate possible relationships with neuromuscular and aerobic capacities. Participants included 46 outfield players from an English Category Two soccer academy. Global positioning system (18 Hz) data were utilised to analyse locomotive outputs across twenty eleven-a-side matches in each age group. Maximal sprinting speed (MSS) and aerobic speed (MAS) were assessed at the beginning of the season. Absolute total distance (TD), high-speed running (HSR), acceleration and deceleration workloads were higher in U18’s and U23’s vs. U16’s (g = 1.09–2.58; p < 0.05), and absolute sprinting distances were higher in U23’s vs. U16’s (g = 0.96; p < 0.05). In addition, relative HSR outputs were higher in U23’s vs. U18’s (g = 1.84–2.07; p < 0.05). Across the whole cohort, players’ MSS was positively associated with absolute HSR and sprinting distances (ρ = 0.53–0.79; p < 0.05) but not with relative parameters. MAS was positively associated with total distance, decelerations, and both absolute and relative HSR outputs (ρ = 0.33–0.56; p < 0.05). Overall, absolute locomotive outputs were significantly higher in U23’s and U18’s vs. U16’s. Locomotive outputs were also associated with maximal sprinting and aerobic speeds. Thus, training programmes should be tailored to competition demands to optimally prepare each age group for competition and reflect the increasing demands of each level of competition. Further, improving physical fitness (speed and endurance) is likely to drive greater outputs in competition. [full text]


    MLB’s Sticky ‘Little Secret’ Is a Problem That’s Not Going Away

    Bleacher Report, Abbey Mastracco from

    … The Cardinals defeated the Chicago White Sox 4-0 at Guaranteed Rate Field, but no one really won this one. Shildt said what others in baseball have been hinting at for a long time: Baseball has a problem with pitchers doctoring baseballs.

    “This is baseball’s dirty little secret, and it’s the wrong time and the wrong arena to expose it,” Shildt said in his postgame press conference. He then seemingly inferred that his wife, Michelle, might be upset about the fine he was going to incur for speaking out, “gosh darn it.” Wife Guy jokes aside, he had a good point: MLB is addressing the symptom but not the disease when it comes to doctoring baseballs with tacky substances by singling out some and not enforcing the rules with others.


    It might be time for an MLB knuckleball pitch comeback

    Los Angeles Times, Bill Shaikin from

    Chris Nowlin would love to teach you how to throw a knuckleball. He runs his “Knuckleball Academy” out of a baseball training facility 10 blocks south of Los Angeles International Airport. He aspires to open his own facility, and he has an investor interested, but there is a bug in the business model.

    “There doesn’t seem to be a whole lot of demand for the knuckleball in Los Angeles,” Nowlin said.

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