Applied Sports Science newsletter – March 2, 2019

How much can you squeeze out of one hockey player? The Chicago Blackhawks are trying to answer that question.

Chicago has spent the last two months frantically trying to erase an ugly start to the regular season. Their start was so awful (they accumulated just 23 points in the opening 30 games, worst in the NHL) that a white-hot run has only marginally improved their playoff chances. One simulation gives them about a 3 per cent chance. Another gives them a 4 per cent chance. In short: barring a blistering run through March and April, the Blackhawks will again miss the postseason.

It isn’t for lack of trying.

… “On our team, I tell our coaches all the time, I want them to have balance in their life,” Kitchens said. “If you don’t have balance, if you’re all this, you’re going to take away from this. Well, what did your family do to deserve to be shortcutted?

“So we’re always going to talk about balance with our players, with our coaches. We want them to have balance because we’re going to get the best out of them on the football field if they have balance in the rest of their life.”

Kitchens’ only concern: that Mayfield arrive for the offseason program April 1 ready to roll. His level of concern: zero.

This study examined adaptations in muscle oxidative capacity and exercise performance induced by two work- and duration-matched exercise protocols eliciting different muscle metabolic perturbations in trained individuals. Thirteen male subjects ( V˙ O2 -max 53.5 ± 7.0 mL·kg-1 ·min-1 ) (means ± SD) performed 8 weeks (three sessions/week) of training consisting of 60 min of moderate intensity continuous cycling (157 ± 20 W) either without (C) or with (C+S) inclusion of 30-s sprints (473 ± 79 W) every 10 min. Total work performed during training was matched between groups. Muscle biopsies and arm venous blood were collected before as well as immediately and 2 h after exercise during the first and last training session. Plasma epinephrine and lactate concentrations after the first and last training session were 2-3-fold higher in C+S than in C. After the first and last training session, muscle phosphocreatine and pH were lower (12-25 mmol·kg d.w.-1 and 0.2-0.4 units, respectively) and muscle lactate higher (48-64 mmol·kg d.w.-1 ) in C+S than in C, whereas exercise-induced changes in muscle PGC-1α mRNA levels were similar within- and between-groups. Muscle content of cytochrome c oxidase IV and citrate synthase (CS) increased more in C+S than in C, and content of CS in type II muscle fibers increased in C+S only (9-17%), with no difference between groups. Performance during a 45-min time-trial improved by 4 ± 3 and 9 ± 3% in C+S and C, respectively, whereas peak power output at exhaustion during an incremental test increased by 3 ± 3% in C+S only, with no difference between groups. In conclusion, addition of sprints in moderate intensity continuous exercise causes muscle oxidative adaptations in trained male individuals which appear to be independent of the exercise-induced PGC-1α mRNA response. Interestingly, time-trial performance improved similarly between groups, suggesting that changes in content of mitochondrial proteins are of less importance for endurance performance in trained males.

… “The research on learning is extremely clear,” says Loren Frank, a professor at the Center for Integrative Neuroscience at the University of California, San Francisco. “To learn something well, you need to study it for a while and then take a break.”

Frank points to the evidence on educational training, which has shown again and again that people retain new information best when their minds are given time off to encode and consolidate. Even outside of study contexts, taking small breaks after digesting new material — whether it’s a news article or an important email — appears to help your brain parse and memorize what you’ve just learned.

To better understand how brains process new information, Frank has conducted brain-scan experiments on rats. He and his colleagues have shown that when rats are allowed to rest after completing an unfamiliar maze, their brains appear to automatically replay the experience of navigating the maze. Confronted later with the same labyrinth, the rats find their way through it more quickly.

Lower limb external maximal power output capacity is a key physical component of performance in many sports. During squat jump and countermovement jump tests, athletes produce high amounts of mechanical work over a short duration to displace their body mass (i.e. the dimension of mechanical power). Thus, jump height has been frequently used by the sports science and medicine communities as an indicator of the power output produced during the jump and by extension, of maximal power output capacity. However, in this article, we contend that squat jump and countermovement jump height are not systematically good indicators of power output produced during the jump and maximal power output capacity. To support our opinion, we first detail why, theoretically, jump height and maximal power output capacity are not fully related. Specifically, we demonstrate that individual body mass, push-off distance, optimal loading and the force-velocity profile confound the jump height–power relationship. We also discuss the relationship between squat jump or countermovement jump height and maximal power output capacity measured with a force plate based on data reported in the literature, which added to our own experimental evidence. Finally, we discuss the limitations of existing practical solutions (regression-based estimation equations and allometric scaling), and advocate using a valid, reliable and simple field-based procedure to compute individual power output produced during the jump and maximal power output capacity directly from jump height, body mass and push-off distance. The latter may allow researchers and practitioners to reduce bias in their assessment of lower limb mechanical power output by using jump height as an input with a simple yet accurate computation method, and not as the first/only variable of interest.

Sleep is far from an inactive time for the brain: while rats (and humans) are asleep, neurons in the hippocampus fire rapidly. After a rat has repeatedly moved from one spot to another, the same neurons that fired while the rat moved “replay” this firing while the rat is asleep, i.e. they fire in the same, but much quicker, pattern. Previously, it was thought that replay patterns only correspond to trips rats had made repeatedly while awake. Writing in Neuron today, Postdoc Federico Stella and Professor Jozsef Csicsvari at the Institute of Science and Technology Austria (IST Austria), show that also when rats roam around freely, the hippocampus replays during sleep, but it does so in a random manner that resembles the famous Brownian motion known from randomly moving particles.

Place cells are cells in the hippocampus that fire when we (or the rats performing the experiments) are in a certain location. In order to form a memory, to be able to recall it and make a decision, they need to replay the firing pattern during sleep. The replay is easy to see in the data and happens at a fast pace, Csicsvari explains: “When a rat is asleep, the hippocampus is silent. But suddenly, lots of place cells fire, then the hippocampus falls silent again. This firing is very time-compressed. One second of firing activity during wakefulness corresponds to about 10 milliseconds of firing when the animal is asleep.”

The purpose of the current paper is to advocate that the athletic skills model (ASM) serves as a suitable framework to structure (developmental) movement programs to enhance physical literacy as a foundation for expertise. Taking the non-linear developmental trajectories into account (including the possibility to follow the linear developmental pathway), the ASM applies three “roads” to reach this goal, that is, the concentric approach, creating challenging environments, and exploiting transfer. Each of these separately or in combination with each other will increase the level of physical literacy, that is creating more functional variation leading to an increasement of possibilities for adaptation of those involved (athletes, PE teachers, and coaches). ASM seeks a life-long physical activity participation and to maintain a balance between performance, fitness and health for the recreational as well for the disable and able (elite) athlete. [full text]

The purpose of this study was to investigate whether the acceleration phase of sprinting could be split into subphases specific to the competitive demands of a soccer match by comparing sprint metrics at various sprint distances in Division I men’s soccer players. Twenty-three Division I men’s soccer athletes completed 2 maximal-effort 20-m sprints from a standing start position through an optical measurement system. Sprint metrics measured included sprint velocity (SV), step length (SL), step frequency (SF), and ground contact time (GCT). Each metric was recorded at approximately 2.5, 6, and 12 m. Sprint metrics at each distance were compared using a 2-tailed, 1-way repeated-measures analysis of variance. The results indicated that SV, SL, and SF were statistically greater at 12 m in comparison with 6 m (p < 0.001) and 2.5 m (p < 0.001), whereas GCT was statistically shorter at 12 m compared with 6 m (p < 0.001) and 2.5 m (p < 0.001). In addition, sprint metrics at 6 m also displayed the same relationships when compared to 2.5 m, with SV, SL, and SF being statistically greater (p < 0.001) at this distance, and GCT being statistically shorter (p < 0.001) as well. These results suggest that the acceleration phase may effectively be differentiated into early, mid, and late subphases based on differences in key sprint metrics at distances of 2.5, 6, and 12 m, respectively, in Division I men's soccer athletes.

Evangelo Spartiatis, 18, still remembers seeing professional soccer players on Facebook and Instagram wearing “some vest” during training. “What is that?” he recalls thinking. “Why are they wearing it?” Well, as it turns out, what was once a curiosity for him three years ago is, now, something he’s all too familiar with. That “vest” Spartiatis talks about is part of a GPS-tracking system he has to wear every day he trains at the Atlanta United Academy, where he plays for the Under-19 development team of the current Major League Soccer (MLS) champion. He’s one of Atlanta United’s 155 youth players training with the Apex GPS, a wearable designed to measure their distance covered, acceleration, deceleration, speed and work rate.

Developed by STATSports, a company founded in 2008 in Northern Ireland, the Apex Athlete Monitoring system consists of a vest that goes between a player’s shoulder blades and a small, lightweight GPS device that attaches to it.

When Jeff Dachis suddenly and unexpectedly learned he had Type 1 diabetes at the age of 46 in September 2013, he was stunned. After all, he ran marathons, followed a healthy diet and never had an inkling of any medical troubles during previous annual physicals.

“I went to the doctor, got about six minutes with a nurse practitioner, an insulin pen, a prescription and a pat on the back, and I was out the door,” Mr. Dachis said. “I was terrified. I had no idea what this condition was about or how to address it.”

Feeling confused and scared, he decided to leverage his expertise in digital marketing, technology and big data analytics to create a company, One Drop, that helps diabetics understand and manage their disease.

The One Drop system combines sensors, an app, and a Bluetooth glucose meter to track and monitor a diabetic’s blood glucose levels, food, exercise and medication.

Researchers at the University of California, Irvine have developed a wearable, disposable respiration monitor that provides high-fidelity readings on a continuous basis. It’s designed to help children with asthma and cystic fibrosis and others with chronic pulmonary conditions.

The inexpensively produced sensors were created by UCI biomedical engineers using the popular children’s toy Shrinky Dinks, thin sheets of plastic that are painted or drawn on and then shrunk with heat.

Placed in two positions – one between the ninth and 10th ribs and another on the abdomen – the Band-Aid-like devices track the rate and volume of the wearer’s respiration by measuring the local strain on the application areas. The information gleaned could, in the case of asthma, help warn of an oncoming attack.

Fiber-based electronics are expected to play a vital role in next-generation wearable electronics. Woven into textiles, they can provide higher durability, comfort, and integrated multi-functionality. A KAIST team has developed a stretchable multi-functional fiber (SMF) that can harvest energy and detect strain, which can be applied to future wearable electronics.

New materials and techniques for collecting power from radio waves could spur mass battery-free IoT sensors.

Boxes filled with papers full of statistics. A4’s full of printed percentages with possession, successful dribbles, intercepted balls, successful passes, failed passes, tackles, lost balls, shots and saves. The examples are endless. Many clubs in professional football still use paper sheets full of figures about players, matches and training sessions. TeamTV wants to make it easier for clubs to keep track of the development of players. With their video analysis platform, clubs can link statistics to video and trainers can mark basic qualities in digital player files. “At some clubs, it is a mess”, says Emiel van Lieshout of TeamTV. ” Unbelievable that they still use so much paper. How cool would it be to have the video with all that data?

The company is currently in the middle of a pilot at Go Ahead Eagles, where they are working with Football Vision, the company of Nangila van Eijk, former professional of Heerenveen, on a player development system and testing with a system that gives information to trainers during the match. “A lot of things happen in a game, so trainers do not always have a good view of what is needed to make the game better. At Go Ahead Eagles we link live statistics to match situations, so the staff can immediately use the data and change something in the field”, explains Van Lieshout.

Real-time measurements of the total loss of sweat, the rate of sweating, the temperature of sweat, and the concentrations of electrolytes and metabolites in sweat can provide important insights into human physiology. Conventional methods use manual collection processes (e.g., absorbent pads) to determine sweat loss and lab-based instrumentation to analyze its chemical composition. Although such schemes can yield accurate data, they cannot be used outside of laboratories or clinics. Recently reported wearable electrochemical devices for sweat sensing bypass these limitations, but they typically involve on-board electronics, electrodes, and/or batteries for measurement, signal processing, and wireless transmission, without direct means for measuring sweat loss or capturing and storing small volumes of sweat. Alternative approaches exploit soft, skin-integrated microfluidic systems for collection and colorimetric chemical techniques for analysis. Here, we present the most advanced platforms of this type, in which optimized chemistries, microfluidic designs, and device layouts enable accurate assessments not only of total loss of sweat and sweat rate but also of quantitatively accurate values of the pH and temperature of sweat, and of the concentrations of chloride, glucose, and lactate across physiologically relevant ranges. Color calibration markings integrated into a graphics overlayer allow precise readout by digital image analysis, applicable in various lighting conditions. Field studies conducted on healthy volunteers demonstrate the full capabilities in measuring sweat loss/rate and analyzing multiple sweat biomarkers and temperature, with performance that quantitatively matches that of conventional lab-based measurement systems.

Japanese technology giant NTT Data began collaborating with Nippon Professional Baseball’s Rakuten Golden Eagles on a project three years ago that turned into a virtual reality simulator. The Eagles began using the system during the 2017 season, and at least one MLB club has joined as a client, too.

While there are several competitors in the field of VR baseball tools, what distinguishes NTT Data’s product is a research-based approach and a new feature incorporating additional sensors. Instead of limiting the hitter-program interaction to just a VR headset, athletes can add a wearable sensor on their pelvis to track hip rotation and another sensor on the bat. NTT also uses Oculus Touch handheld controllers.

The HoloLens 2 reboots augmented reality for Microsoft. It’s got a new fit, larger field of view and adds detailed hand and eye tracking. But one thing it’s still not is a consumer device.

Alex Kipman is a Microsoft technical fellow and inventor of the Kinect and the HoloLens. During a visit to Microsoft’s Redmond campus to try the HoloLens 2 before its debut, we were able to talk to Kipman about his vision for where computing is headed, what HoloLens is becoming and how far away we are from a future where everyday people are actually wearing advanced AR headsets.

To Kipman, and Microsoft, a headset like the HoloLens is one of many devices in which sensors will digest the world with AI.

Background:

Wearable sensor systems have the potential to quantify head kinematic responses of head impacts in soccer. However, on-field use of sensors (eg, accelerometers) remains challenging, owing to poor coupling to the head and difficulties discriminating low-severity direct head impacts from inertial loading of the head from human movements, such as jumping and landing.
Purpose:

To test the validity of an in-ear sensor for quantifying head impacts in youth soccer.
Study Design:

Descriptive laboratory study.
Methods:

First, the sensor was mounted to a Hybrid III headform and impacted with a linear impactor or a soccer ball. Peak linear acceleration (PLA), peak rotational acceleration (PRA), and peak rotational velocity (PRV) were obtained from both systems; random and systematic errors were calculated with Hybrid III as reference. Then, 6 youth soccer players wore sensors and performed a structured training protocol, including heading and nonheading exercises; they also completed 2 regular soccer sessions. For each accelerative event recorded, PLA, PRA, and PRV outputs were compared with video recordings. Receiver operating characteristic curves were used to determine the sensor’s discriminatory capacity in both on-field settings, establishing cutoff values for predicting outcomes.
Results:

For the laboratory tests, the random error was 11% for PLA, 20% for PRA, and 5% for PRV; the systematic error was 11%, 19%, and 5%, respectively. For the structured training protocol, heading events resulted in higher absolute values (PLA = 15.6g± 11.8g) than nonheading events (PLA = 4.6g± 1.2g); the area under the curve was 0.98 for PLA. In regular training sessions, the area under the curve was >0.99 for PLA. A 9g cutoff value yielded a positive predictive value of 100% in the structured training protocol versus 65% in the regular soccer sessions.
Conclusion:

The in-ear sensor displayed considerable random error and substantially overestimated head impact exposure. Despite the sensor’s excellent on-field accuracy for discriminating headings from other accelerative events in youth soccer, absolute values must be interpreted with caution, and there is a need for secondary means of verification (eg, video analysis) in real-life settings.
Clinical Relevance:

Wearable sensor systems can potentially provide valuable insights into head impact exposures in contact sports, but their limitations require careful consideration.

Take Home Message: Many high school athletes had meaningful improvements on both generic and region-specific patient-reported outcome measures after a lower extremity injury; however, remained below normal scores at return to play.

ACL tears are occurring with alarming frequency. Most people are told to have ACL surgery soon after the injury. Many people are under the false assumption that once the ACL surgery and rehabilitation is done the knee is normal. Many people also believe that the majority of athletes return to sports after ACL surgery.

… Students and institutions are grappling with issues like the surge in school shootings and trauma from suicides and sexual assault. But it’s not just the crises that have shaken this generation — it’s the grinding, everyday stresses, from social media pressures to relationship problems to increased academic expectations.

More than 60 percent of college students said they had experienced “overwhelming anxiety” in the past year, according to a 2018 report from the American College Health Association. Over 40 percent said they felt so depressed they had difficulty functioning.

… After my experience trying to cure plantar fasciitis seven years ago, I’ve managed to run more, run faster, and become more minimalist – all without a single complaint from either plantar fascia.

It’s not luck – it’s a systematic plan for prevention that includes general strength, specific exercises, and a training upgrade. And I’m predisposed to foot injuries because of my low arches and over-pronation. I’m not a model of biomechanical efficiency – but I do the best I can with what I have.

First, if you happen to have plantar fasciitis, all hope is not lost. Depending on the severity of the injury, you may be able treat it and be back running with 3-7 days if your injury isn’t too severe. Within two weeks, you should be back to your normal training.

… Though ACL injuries are infrequent in the sport of baseball, I have helped several baseball players rehab and return to play after ACLR over the past year. While most baseball coaches likely have some awareness of shoulder/elbow injuries, they may not have as much exposure or education with players returning from ACLR.

For the rehab professional, it can also be very easy to overlook the sport-specific demands of baseball players when rehabbing from ACLR.

My purpose in writing this article is to provide some insight into recent research regarding return to sport after ACLR and some points to consider when returning to baseball activities after ACLR.

Distance events in Athletics include cross country, the 10,000 m track race, half marathon and marathon road races, and 20 and 50 km race walking events, over different terrain and environmental conditions. Race times for elite performers span ~26 min to >4 h, with key factors for success being a high aerobic power, the ability to exercise at a large fraction of this power, and high economy of movement. Nutrition-related contributors include body mass and anthropometry, capacity to use fuels, particularly carbohydrate (CHO) to produce ATP economically over the duration of the event, and maintenance of reasonable hydration status in the face of sweat losses induced by exercise intensity and the environment. Race nutrition strategies include CHO-rich eating in the hours/days prior to the event to store glycogen in amounts sufficient for event fuel needs, and in some cases, in-race consumption of CHO and fluid to offset event losses. Beneficial CHO intakes range from small amounts, including mouth rinsing, in the case of shorter events to high rates of intake (75-90 g/h) in the longest races. A personalized and practiced race nutrition plan should balance the benefits of fluid and CHO consumed within practical opportunities, against the time cost and risk of gut discomfort. In hot environments, pre-race hyperhydration or cooling strategies may provide a small but useful offset to the accrued thermal challenge and fluid deficit. Sports foods (drinks, gels etc) may assist in meeting training/race nutrition plans, with caffeine and, perhaps, nitrate being performance supplements with evidence-based uses.

We’re all dreaming of warmer weather. Many of us have been working hard toward the goal of looking our best in summer clothing. However, it’s not always the people who work the hardest that come out with the best results. A smarter way to achieve and maintain your weight loss goals involves taking out the guesswork so you can understand your body and work intentionally towards small goals. Understanding fat loss doesn’t have to be as strenuous or as difficult as some fads make it seem. Here are a few simple explanations that may aid in the process of weight loss and improving overall body composition.

Israeli manufacturer Matok V’Kal Ltd. has created a new category for the on-the-go sports nutrition sector with a low-calorie spray which coats the mouth in carbohydrates and tricks the mind into thinking the body has had a boost of energy.

Americans are devouring eggs in numbers not seen in nearly five decades — about 279 per year per person, government forecasts show — continuing a four-year trajectory.

The recent resurgence of eggs — hard boiled, sunny side up or whatever the recipe calls for — follows recent shifts in nutrition guidance from the federal government and an evolving understanding of cholesterol in the American diet.

’14: EPV ’15: Counterpoints, Move or Die ’16: Pressing Game, Court Realty ’17: Possession Sketches, Scorekeeper Bias ’18: Open Spaces, NFL Injury, NBA Replay, Deep Learning Trajectories

here’s a summary thread of them all

… At the top is Denver, which can lay claim to 24 active pros, including the likes of Ethan Horvath, Roger Espinoza, Dillon Serna, Tesho Akindele, Brendan Hines-Ike, and Shane O’Neill. Only eight cities have produced more pros than Denver despite the fact that Denver is only the 19th largest metro area in the country. Denver’s productivity may be even higher on the women’s side of the game; Lindsey Horan, Mallory Pugh, and Jaelene Hinkle all call the city home. Denver’s male players have the benefit of a pipeline to MLS and although the Colorado Rapids are not the most hyped academy in MLS by a long shot, Cole Bassett’s surprisingly quick emergence and investments in players like Matt Hundley indicate that there is more to come.

… Mind you, we’re not talking about a new generation of Ohtani clones. For these position players getting more serious about pitching, and the pitcher getting more serious about position play, the model is probably something closer to Brooks Kieshnick. A two-time winner of the Dick Howser Trophy in college for his double-duty work at the University of Texas, and then the 10th overall pick of the 1993 draft by the Cubs, Kieschnick more or less flopped in 113 games played for Chicago, Cincinnati, and Colorado from 1996-2001. He returned to the mound with the White Sox’s Triple-A Charlotte affiliate in 2002, and then with the Brewers in 2003-2004, where he livened up a pair of 94-loss seasons by hitting .286/.340/.496 with eight homers in 144 PA, and pitching to a 4.59 ERA and 4.13 FIP in 96 innings of relief work. He was more successful in the former year than the latter, totaling 0.8 WAR in his dual capacity overall.

The parallels of this quartet to Kieschnick aren’t exact, as each player has taken his own path, and each of these teams has its own vision of how this will work. In an age of longer pitching staffs and shorter benches, this nonetheless rates as a very interesting innovation, even if the returns don’t yield an Ohtani-level star.

If you watch American football, you’re probably familiar with the concept of “icing the kicker.” For the uninitiated, icing the kicker is not actually the process of freezing the kicker in Carbonite, though that would probably be more fun. Instead, icing the kicker refers to the opposing team calling a time out just before the kicker is about to attempt a field goal or extra point, with the aim of disrupting the kicker’s timing or focus, and causing the kicker to miss said attempt. We saw it happen to the Chicago Bears’ Cody Parkey in the most recent NFC Wildcard game.

Why does this matter? Because a recent rule change has raised the question of whether such a tactic would work in baseball. The twenty-second pitch clock is currently being tested in spring training.

Defeat at QPR was their sixth defeat in 11 in all competitions. From their 10 last games they have taken just 13 points. Whatever the distance covered stats might say, this whole enterprise is running out of steam

The combine isn’t anything different for Mayock, but after years of being on your TV, he’s tackling new territory in Indianapolis this season. Here’s how the Raiders general manager is carrying out the vision for the Jon Gruden 2.0 era.

…

Although United’s overall running distances have gone down under Solskjaer – from 108.1km per game for the team under Jose Mourinho this season to 107.7km under the Norwegian – their total sprints have increased, from 98.6 to 108.6 per match.

Solskjaer, who took over from Mourinho on December 19th, said he had introduced a more intense style of play and that this at least partly explained the injuries.

”It’s probably linked, yes,” he said. “When do you make the change? Do you wait until pre-season and think you will change results by not asking them to run. Or do we start now and show them what the demands of intensity are and how we want to play?

2. Opportunity cost principle: Ask “or what?”
3. Marginal principle: Instead of “how many?” ask “one more?”
4. Interdependence principle: How does this decision relate to others?