Applied Sports Science newsletter – October 6, 2016

Russell Wilson has achieved a kind of perfection, in Pete Carroll’s eyes.

No, he’s not running every play flawlessly, though there wasn’t much to quibble with Sunday in the Seahawks’ 27-17 victory over the New York Jets. Wilson completed 72 percent of his passes (23 of 32) for 309 yards and three touchdowns, a clinical takedown of a tough defense. But no doubt both he and his coach, when they dive into the game film, will find more yards that were there to be had. There is no perfect performance.

Where Wilson has reached the pinnacle, to Carroll, is in his mindset, especially when injuries have him at less than optimal health. In the past, Carroll said that Wilson simply willed himself to get better. On Sunday, he used another esoteric term to describe the same phenomenon: Wilson’s “spirit,” Carroll said, is marvelous to watch.

… Previously a league-average starter, Hendricks has become one of the best pitchers in baseball. But to achieve that level of unmatched consistency, he had to become unpredictable.

Imagine a conference championship game five or 10 years from now. The road team, having traveled to London and Las Vegas for its previous playoff games, arrives in Foxborough and engineers a shocking upset with the help of a surprising strategy: Even though the team’s quarterback is an All-Pro known for picking apart defenses, it employs a scaled-back, run-heavy game plan.

The head coach explains his daring tactical shift at the postgame press conference. “Well, Deshaun’s sleep hygiene has been terrible because of all our travel,” he says. “Our monitors recorded a 37 percent reduction in high-order decision-making because of poor sleep. Meanwhile, Ezekiel’s sleep hygiene has been great, speeding his recovery from that high ankle sprain. So we decided to pound the ball between the tackles.”

Coaching decisions based on sleep habits? Precision monitoring of players’ sleep and how it affects their health and performance? “Sleep hygiene?”

Reversing isn’t easy on a bike – we know, we just tried it and landed with a hefty thump – but there is one thing that can go backwards if you don’t ride regularly: your fitness.

It’s a process called reversibility, or detraining. It’s not something to worry about if you go for three days without riding (in fact you will possibly get fitter, as that rest allows your muscles time to recover and grow, and for the glycogen stores that your muscles use as fuel to replenish), but if you complete a gruelling race or sportive and decide you can’t face even looking at a bike for three months, it’s a different matter.

You probably spent the previous three months training like a beast, so you may be interested to know how long it will take you – hypothetically – to return to your starting point if you opt to do nothing or, worse, are forced off the bike by illness or injury. The answer, of course, is far from straightforward, but as a regular reader of Cycle Science you probably expected nothing less.

For the past 100 years, scientists have understood that different areas of the brain serve unique purposes. Only recently have they realized that the organization isn’t static. Rather than having strictly defined routes of communication between different areas, the level of coordination between different parts of the brain seems to ebb and flow.

Now, by analyzing the brains of a large number of people at rest or carrying out complex tasks, researchers at Stanford University have learned that the integration between those brain regions also fluctuates. When the brain is more integrated people do better on complex tasks. The research was published in Neuron.

“The brain is stunning in its complexity and I feel like, in a way, we’ve been able to describe some of its beauty in this story,” said study lead author Mac Shine, a postdoctoral researcher in the lab of Russell Poldrack.

… It would be impossible to crowdsource a complex project such as conducting an experimental drug trial or sending a human to the Moon, projects that require big-picture visions but also the divvying up and completion of smaller tasks. In these cases, specialised teams need to discuss and collaborate to meet specific goals. So how do we build a smart team?

Collaboration is the hard part, and this is where teams can fall apart. Individuals come to a team with a whole host of cognitive biases, and while one’s intuition might be that a diversity of perspectives could mitigate those biases, collaboration can actually amplify biases such as our tendencies to overestimate how much control we have over events and how much we can generalise from a small sample of data.

Group work also discourages us from making mistakes. While this might sound like an overall good thing, consider that failure is an important part of learning. Acknowledging failure is the hard part of this learning process. But in a group, admitting failure can be a hit to your ego and reputation – an obvious disincentive to owning and learning from your mistakes. In teamwork, we can fall prey to our basest of human desires – being loved, respected, and seen as competent – and avoid owning up to our mistakes.

A more horizontally oriented ground reaction force vector is related to higher levels of sprint acceleration performance across a range of athletes. However, the effects of acute experimental alterations to the force vector orientation within athletes are unknown. Fifteen male team sports athletes completed maximal effort 10-m accelerations in three conditions following different verbal instructions intended to manipulate the force vector orientation. Ground reaction forces (GRFs) were collected from the step nearest 5-m and stance leg kinematics at touchdown were also analysed to understand specific kinematic features of touchdown technique which may influence the consequent force vector orientation. Magnitude-based inferences were used to compare findings between conditions. There was a likely more horizontally oriented ground reaction force vector and a likely lower peak vertical force in the control condition compared with the experimental conditions. 10-m sprint time was very likely quickest in the control condition which confirmed the importance of force vector orientation for acceleration performance on a within-athlete basis. The stance leg kinematics revealed that a more horizontally oriented force vector during stance was preceded at touchdown by a likely more dorsiflexed ankle, a likely more flexed knee, and a possibly or likely greater hip extension velocity.

Eccrine Systems, a company that is commercializing wearable sweat-sensing technology developed at the University of Cincinnati and the Air Force Research Labs at Wright Patterson Air Force Base, has raised $5.5 million. The company set the terms of the round and the largest contributor was CincyTech Fund IV. “Other sources within the CincyTech local, regional and national investor community” filled out the round.

Sweat sensing came to the foreground of digital health earlier this year when a researchers at Stanford University and the University of California-Berkeley published a paper in Nature about a sweat tracking prototype. In an accompanying editorial, University of Cincinnati researcher and Eccrine Systems cofounder Jason Heikenfield argued that sweat sensing would be the next major breakthrough in wearables.

“Today’s commercially available wearables largely rely on decades-old technology,” he wrote at the time. “Their market success is due to a convergence of improved affordability and ergonomics and a rapidly growing consumer awareness of health. The next watershed in wearables will probably be driven by scientific breakthroughs. Sweat biomonitoring arguably has the greatest potential among the emergent non-invasive technologies.”

Ember, a new non-invasive device, measures hemoglobin and pulse rate levels and the data can help athletes track responses to training, high-altitude conditioning and more.

… how can we get a large enough database to “teach computers how to see”? To tackle this issue, Li and her team launched the Image Net project in 2007. Collaborating with more than 50,000 people in 180 countries, they created the biggest image database in the world in 2009: 15 million named and classified images, covering 22,000 categories.

Computers can now train themselves on massive image databases to be able to identify key features, and without human intervention. Like a three-year-old child, computers see millions of named images and understand by themselves the main characteristics of each item. These complex feature-extraction algorithms use deep neural networks and require thousands of millions of nodes.

… When dealing with athletes, in particular elite athletes, appropriate evidence-based scientific principles should apply to the use of both
wearable and performance-enhancing technology. The following recommendations should be considered when using devices: (1) The primary driving principle should be to first do no harm, and direct implications on
athlete health and safety should
be of utmost concern; (2) questions should then be asked regarding the scientific basis for the device; (3) if there is no or minimal scientific
evidence, data should be collected in situ, in a controlled and systematic manner; and (4) implications for the athlete should always be considered (eg, too much information, unnecessary information, or information that may cause stress and anxiety). [pdf]

Globally, the popularity of energy drinks is steadily increasing. Scientific interest in their effects on cardiovascular and cerebrovascular systems in humans is also expanding and with it comes a growing number of case reports of adverse events associated with energy drinks. The vast majority of studies carried out in the general population report effects on blood pressure and heart rate. However, inconsistencies in the current literature render it difficult to draw firm conclusions with regard to the effects of energy drinks on cardiovascular and cerebrovascular variables. These inconsistencies are due, in part, to differences in methodologies, volume of drink ingested, and duration of postconsumption measurements, as well as subject variables during the test. Recent well-controlled, randomized crossover studies that used continuous beat-to-beat measurements provide evidence that cardiovascular responses to the ingestion of energy drinks are best explained by the actions of caffeine and sugar, with little influence from other ingredients. However, a role for other active constituents, such as taurine and glucuronolactone, cannot be ruled out. This article reviews the potentially adverse hemodynamic effects of energy drinks, particularly on blood pressure and heart rate, and discusses the mechanisms by which their active ingredients may interact to adversely affect the cardiovascular system. Research areas and gaps in the literature are discussed with particular reference to the use of energy drinks among high-risk individuals. [full text]

Premier League clubs are pushing to make it easier to sign 14- and 15-year-old players. The move, which has led to the creation of a Premier League working group, would seek to overhaul the Football Association’s existing intermediary regulations, allowing players to formally sign with agents long before their 16th birthday. The clubs hope that such a change would make it easier for them to sign top young talents.

The SAP Tennis Analytics for Coaches powered by SAP HANA App has quickly become an essential tool for coaches and players through all three stages of a tennis match. Before the players even hit the court, the analytic insight gives teams an insider perspective on how to strategize for any given match.

“I look at the SAP app to see how the opponent is serving, how she’s placing the ball, and what she’s doing at crucial times,” said Torben Beltz, coach to World No.1 Angelique Kerber. “We try to focus on that to get Angie ready for the match.”

This study evaluated a procedure for estimating in vivo Achilles tendon (AT) force from ultrasound images. Two aspects of the procedure were tested: (i) accounting for subject-specific AT stiffness and (ii) accounting for changes in the relative electromyographic (EMG) intensities of the three triceps surae muscles. Ten cyclists pedaled at 80?rpm while a comprehensive set of kinematic, kinetic, EMG, and ultrasound data were collected. Subjects were tested at four crank loads, ranging from 14 to 44?N?m (115 to 370?W). AT forces during cycling were estimated from AT length changes and from AT stiffness, which we derived for each subject from ultrasound data and from plantar flexion torques measured during isometric tests. AT length changes were measured by tracking the muscle-tendon junction of the medial gastrocnemius (MG) relative to its insertion on the calcaneus. Because the relative EMG intensities of the triceps surae muscles varied with load during cycling, we divided subjects? measured AT length changes by a scale factor, defined as the square root of the relative EMG intensity of the MG, weighted by the fractional physiological cross-sectional areas of the three muscles, to estimate force. Subjects? estimated AT forces during cycling increased with load (p<0.05). On average, peak forces ranged from 920±96?N (14?N?m, 115?W) to 1510±129?N (44?N?m, 370?W). For most subjects, ankle moments derived from the ultrasound-based AT strains were 5–12% less than the net ankle moments calculated from inverse dynamics (r2=0.71±0.28, RMSE=8.1±0.33?N?m). Differences in the moments increased substantially when we did not account for changes in the muscles? relative EMG intensities with load or, in some subjects, when we used an average stiffness, rather than a subject-specific value. The proposed methods offer a non-invasive approach for studying in vivo muscle-tendon mechanics.