Applied Sports Science newsletter – January 6, 2017

Beyond Cori “Coco” Gauff’s swift movement and muscular forehands lies her most disarming feature: those fierce, dark brown eyes that capture the blatant intensity in her enormous drive.

Recently, Gauff won her first three girls’ 16-under singles matches at the Eddie Herr International Championships, dropping only four games. She has competed credibly in national 18-under events. On Dec. 20, Gauff collected her first Junior Orange Bowl title, winning all seven matches in straight sets.

This from a 12-year-old.

… [Ashton] Eaton wrote: “Frankly there isn’t much more I want to do in sport. I gave the most physically robust years of my life to the discovery and pursuit of my limits in this domain. Did I reach them? Truthfully I’m not sure anyone really does. It seems like we tend to run out of time or will before we run out of potential.”

… Pochettino himself must have been surprised at just how prepared the teenager at the time was to make an immediate impact on the first team. He was confident enough to look to Alli in an attempt to salvage a point at Old Trafford on the opening day of last season, and it only took two more substitute appearances – including a first goal for the club against eventual champions Leicester – to convince the manager that he was ready for a starting berth just five games into the season at Sunderland.

Alli’s integration into the line-up coincided with a 11-match unbeaten run, with the youngster starting all but one of the club’s next 19 league games – with that absence due to a suspension. Indeed, if you exclude bans the midfielder has missed just two league matches since he signed for Spurs, the first being the second game of last season and the latter through injury, ruling him out of this season’s North London derby.

… Defense came easy. His skyscraper height (7’1″) and Mr. Fantastic-like reach (7’8 ½”, the longest wingspan at the NBA Draft Combine) make him impossible to shoot over. His bouncy feet make him hard to circumvent.

But Gobert just couldn’t figure out how to harness all those tools into a steady offensive game. He’d bail out of screens too early or flash to the paint too late. His rail-thin frame prevented him from maintaining strong position in the paint. His wretched foul shooting (under 60 percent for his career entering this season) made him timid while attacking the hoop.

So he began by studying film with Alex Jensen, a Utah Jazz assistant coach.

… the human brain doesn’t have two warring parts, but one unitary system that prioritizes immediately rewarding options over those that pay off later.

The struggle, then, isn’t really between good and bad, but between the future and the present. And what’s exciting about this way of looking at things is that not only does this explain why some people can, and do, win the battle against temptation, but it also gives the rest of us a strategy for how we can do the same.

The NordBord Hamstring Testing System is a fast and easy way to objectively measure eccentric and isometric hamstring strength. The NordBord is the brainchild of Vald Performance, a company based in Brisbane, Australia. Vald Performance is unique, in that the company was born out of a research group at Queensland University of Technology (specifically, Dr. Anthony Shield and Dr. David Opar). I believe that the company’s academic- and research-based origins have helped make a product that is not only easy to use, but also comes with evidence-based guidelines that help drive best practices.

The Premortem

Before a major decision is taken, say to launch a new line of business, write a book, or form a new alliance, those familiar with the details of the proposal are given an assignment. Assume we are at some time in the future when the plan has been implemented, and the outcome was a disaster. Write a brief history of that disaster.

Applied psychologist Gary Klein came up with “The Premortem,” which was later written about by Daniel Kahneman. Of course we are all too familiar with the more common postmortem that typically follows any disaster, along with the accompanying finger pointing. Such postmortems inevitably suffer from hindsight bias, also known as Monday-morning quarterbacking, in which everyone remembers thinking that the disaster was almost inevitable. As I often heard Amos Tversky say, “the handwriting may have been written on the wall all along. The question is: was the ink invisible?”

Purpose

Sprints and accelerations are popular performance indicators in applied sport. The methods used to define these efforts using athlete tracking technology could affect the number of efforts reported. The study aimed to determine the influence of different techniques and settings for detecting high-intensity efforts using Global Positioning System (GPS) data.
Methods

Velocity and acceleration data of a professional soccer match was recorded via 10-Hz GPS. Velocity data was filtered using either a median or exponential filter. Acceleration data was derived from velocity data over a 0.2 s time interval (with and without an exponential filter applied) and a 0.3 s time interval. High-speed running (≥4.17 m.s-1), sprint (≥7.00 m.s-1) and acceleration (≥2.78 m.s-2) efforts were then identified using minimum effort durations (0.1 to 0.9 s) to assess differences in the total number of efforts reported.
Results

Different velocity filtering methods resulted in small to moderate differences (Effect Size; 0.28 – 1.09) in the number of high-speed running and sprint efforts detected when minimum duration was <0.5 s and small to very large differences (ES; -5.69 – 0.26) in the number of accelerations when minimum duration was <0.7 s. There was an exponential decline in the number of all efforts as minimum duration increased, regardless of filtering method, with the largest declines in acceleration efforts. Conclusions

Filtering techniques and minimum durations substantially affect the number of high-speed running, sprint and acceleration efforts detected with GPS. Changes to how high-intensity efforts are defined affect reported data. Therefore, consistency in data processing is advised.

Self-report measures of physical activity (PA) are easy to use and popular but their reliability is often questioned. Therefore, the general aim of the present study was to investigate the association of PA questionnaires with accelerometer derived PA, in a sample of adolescent boys. In total, 191 pubertal boys (mean age 14.0 years) completed three self-report questionnaires and wore an accelerometer (ActiGraph GT1M) for 7 consecutive days. The PA questionnaires were: International Physical Activity Questionnaire-Short Form (IPAQ-SF), Tartu Physical Activity Questionnaire (TPAQ), and the Inactivity subscale from Domain-Specific Impulsivity (DSI) scale. All three questionnaires were significantly correlated with accelerometer derived MVPA: the correlations were 0.31 for the IPAQ-SF MVPA, 0.34 for the TPAQ MVPA and -0.29 for the DSI Inactivity scale. Nevertheless, none of the questionnaires can be used as a reliable individual-level estimate of MVPA in male adolescents. The boys underreported their MVPA in IPAQ-SF as compared to accelerometer-derived MVPA (respective averages 43 and 56 minutes); underreporting was more marked in active boys with average daily MVPA at least 60 minutes, and was not significant in less active boys. Conversely, MVPA index from TPAQ overestimated the MVPA in less active boys but underestimated it in more active boys. The sedentary time reported in IPAQ-SF was an underestimate as compared to accelerometer-derived sedentary time (averages 519 and 545 minutes, respectively). [full text]

Fitness apparel giant Under Armour is expanding its collaboration with Johns Hopkins Medicine to back up its health and fitness apps with scientific research and expertise.

Under Armour has several apps, including UA Record, MapMyFitness, MyFitness Pal and Endomondo, with more than 190 million registered users.

Under the new agreement, Hopkins will provide clinical and research-based guidance in the areas of sleep, fitness, activity and nutrition.

In the field of gait recognition from motion capture data, designing human-interpretable gait features is a common practice of many fellow researchers. To refrain from ad-hoc schemes and to find maximally discriminative features we may need to explore beyond the limits of human interpretability. This paper contributes to the state-of-the-art with a machine learning approach for extracting robust gait features directly from raw joint coordinates. The features are learned by a modification of Linear Discriminant Analysis with Maximum Margin Criterion so that the identities are maximally separated and, in combination with an appropriate classifier, used for gait recognition. Experiments on the CMU MoCap database show that this method outperforms eight other relevant methods in terms of the distribution of biometric templates in respective feature spaces expressed in four class separability coefficients. Additional experiments indicate that this method is a leading concept for rank-based classifier systems.

In an attempt to better identify and inform the energy requirements of elite soccer players, we quantified the energy expenditure (EE) of players from the English Premier League (n=6) via the doubly labeled water method (DLW) over a 7-day in-season period. Energy intake (EI) was also assessed using food diaries, supported by the remote food photographic method and 24 h recalls. The 7-day period consisted of 5 training days (TD) and 2 match days (MD). Although mean daily EI (3186 ± 367 kcals) was not different from (P>0.05) daily EE (3566 ± 585 kcals), EI was greater (P<0.05) on MD (3789 ± 532 kcal; 61.1 ± 11.4 kcal.kg-1 LBM) compared with TD (2956 ± 374 kcal; 45.2 ± 9.3 kcal.kg-1 LBM, respectively). Differences in EI were reflective of greater (P<0.05) daily CHO intake on MD (6.4 ± 2.2 g.kg-1) compared with TD (4.2 ± 1.4 g.kg-1). Exogenous CHO intake was also different (P<0.01) during training sessions (3.1 ± 4.4 g.h-1) versus matches (32.3 ± 21.9 g.h-1). In contrast, daily protein (205 ± 30 g.kg-1, P=0.29) and fat intake (101 ± 20 g.kg-1, P=0.16) did not display any evidence of daily periodization. Although players readily achieve current guidelines for daily protein and fat intake, data suggest that CHO intake on the day prior to and in recovery from match play was not in accordance with guidelines to promote muscle glycogen storage.

… It is likely that this winter’s window will be the biggest yet, and is predicted to break the current record of £225m spent by clubs in 2011. The overall spending for the season should head past £1.4 billion – the summer 2015 window alone generated gross spending of £1.165 billion.

There are two factors at play in this prediction. First, the financial significance of staying in the League is bigger than ever. Holding onto a Premier League place is worth an estimated £130m to clubs so teams fighting relegation will feel under even more pressure to spend big. The risk here is clearly that their financial future could be threatened. Clubs can stretch too far, however, in tying players to big wages and long term contracts, an approach Queens Park Rangers followed with players such as Joey Barton, Bobby Zamora, Richard Dunne, Rio Ferdinand, Shaun Wright-Phillips, and Adel Taarabt. The club is now lying in 17th spot in the Championship, the second tier of English football.

A look at the pressures of rising costs, falling revenue and what, if anything, universities can do about it.

The phrase “student-athlete” will be repeated with chanting monotony during college football’s national championship week, so let’s pause to consider that talcum-dull term. It would be nice to find a better phrase, but what to replace it with? Scholarship athletes are uniquely hard to describe, somehow more loaded with privileges and responsibilities than the average student-cheerleader or student-student. What should we compare them to? Apprentices? This question was recently put to a panel of NCAA-friendly federal judges, who after due consideration came up with their own startling comparison: prisoners.

That’s right. Prisoners.