Applied Sports Science newsletter – August 9, 2016

Rafael Nadal admits that he has taken a gamble by participating in the Olympic Games, given the slow recovery of his left wrist from the tendon injury that had kept him off the court since the French Open.

Nadal played his first match since May against Federico Delbonis at the Olympic Tennis Centre and showed unexpectedly sharp form, hustling Delbonis out of the competition with a 6-2, 6-1 victory.

3x Stanley Cup Champion, 2x Olympic Gold Medalist, and NHL All-Star, Duncan Keith talks about toughness.

… “He had no idea what to do with the rest of his life,” his longtime coach Bob Bowman told the Times. “It made me feel terrible. I remember one day I said: ‘Michael, you have all the money that anybody your age could ever want or need; you have a profound influence in the world; you have free time—and you’re the most miserable person I know. What’s up with that?’”

Phelps had staked his entire identity on his swimming career, staying singularly focused on a goal and achieving wild success, but over the years he did not develop other parts of himself. While in rehab at the Meadows treatment center in Arizona, he came to the conclusion that embracing emotional vulnerability was the only way to get to the other side.

He read books like Viktor Frankl’s Man’s Search for Meaning, Joseph Murphy’s The Power of Your Subconscious Mind, and Rick Warren’s The Purpose-Driven Life. By developing a more complex view of himself, Phelps began to build his psychological strength again, and today—older (31), engaged and a new father—he appears stronger than ever.

Objectives

Evaluate the validity of a commercially available wearable device, the Vert, for measuring vertical displacement and jump count in volleyball athletes. Propose a potential method of quantifying external load during training and match play within this population.
Design

Validation study
Methods

The ability of the Vert device to measure vertical displacement in male, junior elite volleyball athletes was assessed against reference standard laboratory motion analysis. The ability of the Vert device to count jumps during training and match-play was assessed via comparison with retrospective video analysis to determine precision and recall. A method of quantifying external load, known as the load index (LdIx) algorithm was proposed using the product of the jump count and average kinetic energy.
Results

Correlation between two separate Vert devices and three-dimensional trajectory data were good to excellent for all jump types performed (r?=?0.83-0.97), with a mean bias of between 3.57-4.28?cm. When matched against jumps identified through video analysis, the Vert demonstrated excellent precision (0.995-1.000) evidenced by a low number of false positives. The number of false negatives identified with the Vert was higher resulting in lower recall values (0.814-0.930).
Conclusions

The Vert is a commercially available tool that has potential for measuring vertical displacement and jump count in elite junior volleyball athletes without the need for time-consuming analysis and bespoke software. Subsequently, allowing the collected data to better quantify load using the proposed algorithm (LdIx).

Whether it’s drug scandals, pollution problems or sheer curiosity at the incredible capabilities of the athletes, the Olympic Games have long fascinated researchers as well as the general public.

In recent decades, research has increased on the selection of Olympic sites, environmental issues and the Games’ ability to encourage people to participate in sport, says sports-medicine specialist Lars Engebretsen, who heads science and research for the International Olympic Committee.

The Olympics don’t typically inspire researchers to start new fields — instead, they tend to feed into ongoing studies, says Vanessa Heggie, a historian of science and sports medicine at the University of Birmingham, UK.

As the 2016 summer Games kick off in Rio de Janeiro, Nature uses bibliometrics to provide insight into the who, where, what, how and why of Olympic science.

Where does fatigue come from? It doesn’t come from the body. Even when people exercise to exhaustion, studies have shown that there is fuel left in the tank – one found there was enough energy left in muscle tissue for participants to have kept going for another seven or eight minutes. The brain puts the brakes on, stepping in to stop us from over-exerting and injuring ourselves long before we reach our actual limits.

According to the latest research, our physical endurance is determined by our “perception of effort” – how much work the brain thinks that the body has done. But the brain can be tricked. In Brazil, a group of scientists improved power output in cyclists by 10% by running a small electric current through the brain. Elsewhere, it has been shown that giving athletes incorrect information about the temperature can help them maintain their performance in hot conditions, and that lying to them about their split times can help them break personal bests.

With the new Premier League season soon to kick off we are delighted to bring you an interview with Head of Sports Science at Swansea City AFC, Jonny Northeast. According to public statistics on sites such as Premier Injuries and Physio Room (yes they are not perfect but they still have their uses), Swansea were one of the best teams across the league last season for player availability (http://www.physioroom.com/news/english_premier_league/2015_16/injury_analysis.php).

We asked Jonny about his role, the tools they use to try to minimise injury risk, the culture at Swansea City, research and professional development.

When Michael Phelps took to the water to swim in the 4×100-meter relay Sunday, many noticed weird purple circles covering his right shoulder. The dots are the result of cupping, the latest alternative therapy elite athletes are using to try to recover faster and perform better.

But as with a lot of alternative therapies, the science on these medicinal hickeys is pretty inconclusive, suggesting you may not need to sprint off to a cupping practitioner to try it out on your sore muscles.

I’m training for my fourth marathon and attempting to improve my time. This time around I’m struggling with lack of energy and strength in my workouts. The reason I’m writing is that it’s lasted for several weeks now, and I’m headed into my longest and hardest runs this month. Have you seen this before in the runners you’ve coached, and what can I do to get back to my normal energy levels?

It is wise to reach out for guidance when things are out of balance. It is common to experience short bouts of fatigue during the season, especially after particularly long and demanding runs. When the symptoms last longer than that, though, it’s time to take a closer look at what may be contributing to your ongoing fatigue.

I have seen this in my athletes, and in most cases if you look at the following variables, you can identify the culprit and modify your plan to preserve your training season. The first step is becoming aware, so you’ve already been there, done that. Let’s move on the step two and see if any of these apply to you.

1/ Progression load

I knew Eero Mäntyranta had magic blood, but I hadn’t expected to see it in his face. I had tracked him down above the Arctic Circle in Finland where he was—what else?—a reindeer farmer.

He was all red. Not just the crimson sweater with knitted reindeer crossing his belly, but his actual skin. It was cardinal dappled with violet, his nose a bulbous purple plum. In the pictures I’d seen of him in Sports Illustrated in the 1960s—when he’d won three Olympic gold medals in cross-country skiing—he was still white. But now, as an older man, his special blood had turned him red.

Mäntyranta, who passed away in late 2013, had a rare gene mutation that spurred his bone marrow to wildly overproduce red blood cells. Red cells convey oxygen to the muscles and the more you have, the better your endurance. That’s why some endurance athletes—most prominently Lance Armstrong—inject erythropoietin (EPO), the hormone that cues your bone marrow to produce red blood cells.

Convincing the U.S. women’s soccer team that it needs an edge in Rio is like telling 1992 Michael Jordan he should practice his jump shot. With three World Cup trophies and four Olympic gold medals to its name, the Women’s National Team is the most dominant in soccer history—male or female. And they’re favored to win again.

This time, however, the team will rely on advanced technology, in the form of GPS tracking devices, to provide a boost. Thanks to the miniaturization and power of sensors, it captures several metrics on every player on the field, down to speed, lateral movements, and impacts. That specificity empowers the team’s trainers to tailor workouts and recovery programs—both of which are crucial to improving performance—to each individual.

“We’ve always developed very talented players,” says center back Becky Sauerbrunn, the team’s defensive anchor. “But at the global level, other teams are catching up. So we’re trying to raise the bar, and that’s where cutting-edge tech comes in.” It’s women’s soccer 2.0.

Proper nutrition is essential for physical development and athletic performance. Consider the physical demands placed on you by practice; competition; strength, speed, agility, plyometric, and conditioning training; and your rigorous schedule. Healthy eating habits play a valuable role in your pursuit of excellent performance.

Coaches are responsible for providing athletes with the support they require to be successful. A good coach provides the education, assessment, and support necessary to reshape nutritional habits. A coach who promotes the use of convenient, healthy snacks, recovery foods, and vitamin and mineral supplements, and who requires water bottles for every athlete demonstrates a commitment to the development of optimal nutrition habits. This support makes it possible for players to achieve a lifestyle that includes proper nutrition choices.

Performance nutrition education focuses on three primary goals: proper meal planning, balance and variety in food choices, and positive eating habits.

Planning your protein consumption with precision could pay dividends, according to several new findings revealed at American College of Sports Medicine’s (ACSM) conference.

Firstly, researchers suggested that the “anabolic window of opportunity” (optimal time to eat protein after a workout to build muscle) is longer than initially thought with muscles remaining in prime building-mode for up to two days after a weight-lifting session.

When it comes to refueling depleted muscle glycogen, however, the advice is still to aim for within an hour or two of exercise.

Survival analysis is used to study the time until some event of interest (often referred to as death) occurs. Time could be measured in years, months, weeks, days, etc. The event could be anything of interest. It could be an actual death, a birth, a Pokemon Go server crash, etc. In this post we are interested in how long drafted NFL players are in the league, so the event of interest will be the retirement of drafted NFL players. The duration of time leading up to the event of interest can be called the survival time. In our case, the survival time is the number of years that a player was active in the league (according to Pro Football Reference).

Some of the players in this analysis are still active players (e.g. Aaron Rodgers, Eli Manning, etc.), so we haven’t observed their retirement (the event of interest). Those players are considered censored. While we have some information about their career length (or survival time), we don’t know the full length of their career. This specific type of censorship, one in which we do not observe end of the survival time, is called right-censorship. The methods developed in the field of survival analysis were created in order to deal with the issue of censored data. In this post we will use one such method, called the Kaplan-Meier estimator, to estimate the survival function and construct the survival curve for an NFL career.

This is a script for visualization of NBA games from raw SportVU logs.

If you admire both Spurs’ and Warriors’ ball movement, Brad Stevens’ playbook, or just miss KD in OKC you’ll find this entertaining.