Applied Sports Science newsletter – May 2, 2016

The combination of natural born talent, hard work, an excellent support system and the tremendous support given to the U.S. Youth National Team programs has allowed Mallory Pugh to have some unique soccer experiences before the age of 18.

She started in a U-20 Women’s World Cup at 16-years-old, debuted for the full U.S. National Team at 17, scored her first international goal at the senior level in front of more than 23,000 fans and became the youngest U.S. female player ever to play in an Olympic Qualifying match.

Those accomplishments have earned her the acclaim of being one of the top young players in the world.

… “I rested him — that was me giving him a rest,” Vanney quipped about subbing Giovinco out in the 89th minute of last weekend’s 2-0 win over the Montreal Impact. The win propelled TFC to third place in the Eastern Conference with a solid 3-2-2 record and 11 points. … It’s been a heavy workload for the Atomic Ant, but Vanney makes no apologies for it, and he doesn’t plan on giving him a break anytime soon.

Riyad Mahrez is the first African player to win the Player of the Year award in the Premier League. The Red Bulletin columnist Raphael Honigstein looks at the Algerian player’s stellar rise to fame and why next season will be an entirely different ball game.

A little less than a month after Canadian tennis star Genie Bouchard retired from her second-round match in Charleston against Lourdes Dominguez Lino of Spain with a recurrence of her abdominal injury, she return to action at the joint WTA-ATP Tour tournament in Madrid, Spain this coming week.

But she will do it without coach Thomas Hogstedt.

Atlanta United hired Richard Money to oversee the development of its academy, the talent pipe through which will expectantly flow first-team players.

It is an important job for several reasons: most academy players start as local residents who support the local club, so playing for the academy provides extra motivation. Second, it’s typically cheaper to develop first-team players rather than to try to buy them through the transfer market. There are many more reasons.

“…the measure of our success is not by how many championships we win, it’s about how many players we can develop and take through the pathway,” Money said.

The purpose of this study was to examine whether offensive and defensive collective behaviours emerging in six-a-side football games (GK+5 vs. 5+GK) varied according to age-related practice experience of young, male players (U16, U17 and U19 yrs). Players’ were not instructed to implement specific tactical plans and their movement trajectories (2D analyses) were recorded using 10 GPS units. Four common measures of team dispersion investigated in previous research (surface area, stretch index, length and width of a team) were used to analyse team performance behaviours. After recording these collective variables, we used sample entropy (SampEn) and cross-sample entropy (Cross-SampEn) measures to assess the regularity and synchronization of participant actions in teams. Results demonstrated clear age-related variations in effects on the collective performance measures analysed. In attacking phases, older and more experienced players occupied a greater surface area and displayed higher values of team width and stretch index. In defensive phases, significant differences were observed in team length and stretch index. Cross-SampEn analysis demonstrated a greater synchronization between offensive and defensive surface areas and team width in older age groups (U17 and U19 yrs). Data suggest how coaches can manipulate practice task constraints to enhance development of team tactical performance behaviours in developing footballers between 16 and 19 yrs of age. [full length article available]

With 100 days to go until the Rio Olympics, years of training are drawing to a close and eyes are focusing on the prize of an Olympic Gold.

So what makes for the best run-in to the Games? Team GB’s rowing unit gave Marcus Thompson an insight into their recipe for success – and how data is playing an increasingly important role.

Leicester’s rise from promotion in 2014, to relegation candidates last season, to the brink of a Premier League title, is nothing short of remarkable.

Jamie Vardy, Riyad Mahrez and N’Golo Kante have rightly hogged the headlines, Claudio Ranieri has been hailed as a genius, and Nigel Pearson remains a footnote that no-one can forget for his work in setting up this dream scenario.

But away from the limelight, Leicester have a back-room team helping to make the dream a reality.

Sportsmail looks at the men behind the miracle… [commercial videos autoplay]

… when does the therapeutic dose of regular sports training turn into something more damaging? And, more importantly, what can we do to prevent this & keep an athlete’s relationship with sport ‘healthy’?

First, a little background on the biochemical basis for addiction that will show how the physical training of sport fits in…

Dopamine is a neurotransmitter in the brain that serves an important role in reinforcing behavior. It can be thought of as the ‘wanting’ neurotransmitter. Low levels of dopamine lead to craving & ‘seeking’ behaviors. Low levels of dopamine have been implicated in the development of ADHD (Wu et al., 2012) and more significantly to our purposes, drug addiction, particularly addiction to stimulants such as cocaine or amphetamines….

The use of global positioning systems (GPS) has increased dramatically over the last decade. Using signals from orbiting satellites, the GPS receiver calculates the exact position of the device and the speed at which the device is moving. Within team sports GPS devices are used to quantify the external load experienced by an athlete, allowing coaches to better manage trainings loads and potentially identify athletes who are overreaching or overtraining. This review aims to collate all studies that have tested either (or both) the validity or reliability of GPS devices in a team sport setting, with a particular focus on (a) measurements of distance, speed, velocities, and accelerations across all sampling rates and (b) accelerometers, player/body load and impacts in accelerometer-integrated GPS devices. A comprehensive search of the online libraries identified 22 articles that fit search criteria. The literature suggests that all GPS units, regardless of sampling rate, are capable of tracking athlete’s distance during team sport movements with adequate intraunit reliability. One Hertz and 5Hz GPS units have limitations in their reporting of distance during high-intensity running, velocity measures, and short linear running (particularly those involving changes of direction), although these limitations seem to be overcome during measures recorded during team sport movements. Ten Hertz GPS devices seem the most valid and reliable to date across linear and team sport simulated running, overcoming many limitations of earlier models, whereas the increase to 15Hz GPS devices have had no additional benefit.

Background: The Functional Movement Screen (FMS) is utilized by professional and collegiate sports teams and the military for the prevention of musculoskeletal injuries.

Hypothesis: The FMS demonstrates good interrater and intrarater reliability and validity and has predictive value for musculoskeletal injuries.

Study Design: Systematic review and meta-analysis.

Methods: A systematic review and meta-analysis were conducted using a computerized search of the electronic databases MEDLINE and ScienceDirect in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Extracted relevant data from each included study were recorded on a standardized form. The Cochran Q statistic was utilized to evaluate study heterogeneity. Pooled quantitative synthesis was performed to measure the intraclass correlation coefficient (ICC) for interrater and intrarater reliability, along with 95% CIs, and odds ratios with 95% CIs for the injury predictive value for a score of ?14.

Results: Eleven studies for reliability, 5 studies for validity, and 9 studies for the injury predictive value were identified that met inclusion and exclusion criteria; of these, 6 studies for reliability and 9 studies for the injury predictive value were pooled for quantitative synthesis. The ICC for intrarater reliability was 0.81 (95% CI, 0.69-0.92) and for interrater reliability was 0.81 (95% CI, 0.70-0.92). The odds of sustaining an injury were 2.74 times with an FMS score of ?14 (95% CI, 1.70-4.43). Studies for validity demonstrated flaws in both internal and external validity of the FMS.

Conclusion: The FMS has excellent interrater and intrarater reliability. Participants with composite scores of ?14 had a significantly higher likelihood of an injury compared with those with higher scores, demonstrating the injury predictive value of the test. Significant concerns remain regarding the validity of the FMS.

Scientists at Tufts have determined that leg muscle power—the capability of the leg muscles to rapidly exert force—is a more accurate gauge of the severity of knee osteoarthritis than simple leg strength, a finding that could lead to better diagnosis and treatment of the often debilitating disease.

Led by Kieran F. Reid, an exercise physiologist at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts, the study, which appeared in the journal Arthritis and Rheumatology, examined the relationships between leg muscle strength, leg muscle power and perceived knee pain in people with osteoarthritis of the knee.

“The key difference between training for building strength versus power is the speed at which the training is performed,” says Reid. “You can train on the same machines to develop strength and power, and with the same exercises—leg curl, leg extension, bicep curl, etc.—but to develop muscle power you have to perform the exercise very fast or as fast as you possibly can.”

… Successes such as Leicester’s, gift-wrapped for screenwriters, inevitably inspire a rationalist backlash. “Debunking” the Leicester miracle has now become a popular intellectual counter-rhythm, as though the romantic bandwagon needs to be kept in check.

The revisionists have proposed that Leicester’s success is about systems, not romance. Leicester have invested in marginal gains, ranging from a pioneering scouting system to rotational fouling, aimed at reducing yellow cards. This savviness, however, doesn’t undermine the story at all: doubtless David had a very elastic sling when he felled Goliath. Besides, we do not have to turn Leicester into saints to marvel at their success.

Money buys quality. Quality in football is, to a large extent, determined by the individual actions of a player that are measurable. Goals scored, passes completed, assists given, interceptions made; the list goes on.

As analytics in football continues to develop more advanced and nuanced ways of measuring and interpreting this data, more detailed questions can be asked about a player’s actions and subsequently, their contribution. Has a striker outperformed their xG values? What percentage of a midfielder’s interceptions are converted into counter-attacks? These are the type of questions that the recruitment departments of clubs all over the world are asking (or should be asking). And they are good questions – questions whose answers will go a substantial way to deciding the location of the bank account into which millions of pounds will be deposited. Money buys quality, right?

The problem here is that, as with so much in the contemporary interpretation of the game of football, we are too concerned with the ball itself. These metrics are almost exclusively based on actions that involve, in one way or another, the player touching the ball.

.. Football is far messier, with a jumble of clashes affecting the outcome. It is also relatively low-scoring, in contrast to baseball or basketball – further reducing the number of notable events. Before Dixon and Coles came along, analysts such as Charles Reep had even concluded that “chance dominates the game”, making predictions all but impossible.

Successful prediction is about locating the right degree of abstraction. Strip away too much detail and the analysis becomes unrealistic. Include too many processes and it becomes hard to pin them down without vast amounts of data. The trick is to distil reality into key components: “As simple as possible, but no simpler,” as Einstein put it.

Dixon and Coles did this by focusing on three factors – attacking and defensive ability for each team, plus the fabled “home advantage”. With ever more datasets now available, betting syndicates and sports analytics firms are developing these ideas further, even including individual players in the analysis. This requires access to a great deal of computing power. Betting teams are hiring increasing numbers of science graduates, with statisticians putting together predictive models and computer scientists developing high-speed software.