Applied Sports Science newsletter – September 19, 2015

… Gordon, who exercised his player option in June to return to the New Orleans Pelicans, says he’s as healthy as he’s been since his last season in Los Angeles. He’s training instead of rehabbing for the first summer in years. He’s ecstatic about his new coach, Alvin Gentry, late of the champion Warriors. He’s 26, younger than his former AAU teammate Derrick Rose and younger than Curry, the reigning MVP. Gordon thinks he can still make his first All-Star team and that he can help make the Pelicans a championship contender.

… SA: Is a focus on intensity an attempt to make up for a lack of a deep soccer culture?

TOBIAS BISCHOF: I definitely agree with that. The intensity here is a make up for the … how do I say, the deeper knowledge of soccer. In Europe the game is lived more, the game is breathed more, kids watch soccer constantly and therefore learn about soccer constantly through not just training and coaching but through TV, radio and all those other outlets as well.

Jurgen Klinsmann, the Head Coach for the U.S. Men’s National Team believes we must do more to help our youth develop. Now, U.S. Soccer Federation changes youth soccer and next year, the landscape will look very different.

Who knew U.S. Soccer would mandate change? Now, stepping up to end the controversy on what is right, U.S. Soccer will make youth soccer better – especially for players ages 6 to 12 (the Zone 1 environment) where there has been too much emphasis on winning and not enough on developing player skills.

INTRODUCTION:

Non-local muscle fatigue (NLMF) is characterized by muscle performance impairments in a contralateral or remote non-exercised muscle(s) following a fatiguing protocol of a different muscle group(s). This topic is of interest as it affords insights into physiological determinants of muscle fatigue and may provide practical applications concerning the order of exercises in training and rehabilitation programs.
… RESULTS:

The literature is conflicting with approximately half of the studies reporting NLMF effects (32 of 58 measurements). However, on closer examination 76 % of outcome measures of the lower limbs reported NLMF effects (23 of 30 measurements) compared to only 32 % in the upper body (9 of 28 measurements). Thus, it appears that NLMF effects may be muscle group dependent. Also, tests that involve prolonged or repetitive contractions provide clearer evidence of NLMF. Other variables potentially influencing the size of the NLMF effect include the fatigued muscle groups, the protocols used to elicit the fatigue, gender and training background of participants.
CONCLUSION:

While the NLMF literature is conflicting, certain variables appear to affect NLMF responses which can account for some of the discrepancies. Furthermore, the NLMF effects may be attributed to four different but interconnected pathways: neurological, biochemical, biomechanical and psychological.

The Minnesota Timberwolves have hired former Detroit Pistons physical therapist Arnie Kander to head their revamped athletic training staff.

Purpose: The aim of the study was to investigate whether heart rate recovery (HRR)
may represent an effective marker of functional overreaching (f-OR) in endurance
athletes. Methods and Results: Thirty-one experienced male triathletes were tested (10
control and 21 overload subjects) before (Pre), and immediately after an overload
training period (Mid) and after a 2-week taper (Post). Physiological responses were
assessed during an incremental cycling protocol to exhaustion, including heart rate,
catecholamine release and blood lactate concentration. Ten participants from the
overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% decreased
performance with concomitant high perceived fatigue). Additionally, only the f-OR
group demonstrated a 99% chance to demonstrate an increase in HRR during the
overload period (+8 ± 5 bpm, large effect size). Concomitantly, this group also revealed
a >80% chance of decreasing blood lactate (-11 ± 14%, large), plasma norepinephrine
(-12 ± 37%, small) and plasma epinephrine peak concentrations (-51 ± 22%,
moderate). These blood measures returned to baseline levels at Post. HRR change
was negatively correlated to changes in performance, peak HR and peak blood
metabolites concentrations. Conclusion: These findings suggest that i) a faster HRR is
not systematically associated with improved physical performance, ii) changes in HRR
should be interpreted in the context of the specific training phase, the athletes
perceived level of fatigue and the performance response; and, iii) the faster HRR
associated with f-OR may be induced by a decreased central command and by a lower
chemoreflex activity.

Raleigh, North Carolina-based Valencell, which embeds its health and medical sensors in some wearable devices, most notably in sensor-equipped headphones, raised $2.6 million in a combination of debt and equity, according to an SEC filing. … Valencell doesn’t sell products directly to consumers, but instead licenses out its PerformTek sensors to be incorporated into different wearables. Its technology is a part of various wearables, including the iRiver On headset and LG’s Heart Rate Earphones, which are designed to work in tandem with LG’s LifeBand activity tracker. Its tech is also in two armband trackers from Scosche: the Rhythm + and Rhythm Smart and Atlas, a wristband designed to detect specific exercises.

On 16 September we interviewed Sean Clarkson about his paper on using the Microsoft Kinect for anthropometry

With healthcare costs rising across the developed world, many argue that the rise of wearable technology as a way to determine health insurance premiums is inevitable–and one company in Switzerland is putting the idea to the test.

CSS, one of the country’s biggest health insurers, launched a pilot project in July, in which the company tracks the movements of 2,000 volunteers on a daily basis using digital pedometers. The program “should reveal whether and how insurance companies can introduce an appropriate offer tailored to customers’ needs,” Volker Schmidt, the company’s head of technology, told The Local.

On August 24th, the Los Angeles Dodgers started its Accelerator with R/GA, the internationally recognized ad firm. Our company, FieldLevel, was announced as one of the 10 companies participating in the program. According to the program’s directors, they scoured the Earth looking for ideal companies, evaluating roughly 600 enterprises from over 30 countries.

To say our team was at first apprehensive about joining would be a grotesque understatement, like calling the Titanic a “boat” or the 1996 Chicago Bulls “just a basketball team.” We flat out rejected the notion. Over several years, we’d built a profitable company with formidable market position. We’d executed significant partnerships, expanded to over 20 countries, and increasingly landed just about any meeting that we desired.

Savvy sports organizations, including the Los Angeles Dodgers and Cleveland Cavaliers, increasingly look to the startup community for technologies that can enhance the fan experience and improve business operations, on and off the field.

Over three years ago, an article from ESPN, featuring Dr. James Andrews, highlighted the interest in stem cells as a way to help athletes heal. Platelet-Rich Plasma (PRP) injections for athletes and other attempts to accelerate healing are exciting and very promising. Unfortunately, the media misunderstand regenerative medicine and fail to see the bigger picture of what else is needed to keep athletes on the court or the field. As a medical professional who employs PRP injections and collaborates with doctors who use stem cells, my perspective is that we need to put prevention first, and deploy therapeutics only when necessary. I believe in regenerative medicine, but without doing the basics first through blood analysis, reactive medical care can be severely limiting.

Take Home Message: More than half of the sports medicine staff experience pressure from coaches and athletes to release athletes prematurely to play following a concussion.

Background: Young athletes who have had anterior cruciate ligament (ACL) reconstruction demonstrate suboptimal rates of return to sport, high rates of second ACL injuries, and persistent movement asymmetries. Therefore, the influence of musculoskeletal impairments on movement mechanics in this population needs to be further evaluated.

Hypothesis: The primary hypothesis was that among young athletes who have had ACL reconstruction, those with greater quadriceps strength asymmetry would demonstrate altered single-leg drop-landing mechanics at return to sport compared with individuals with more symmetric quadriceps strength and also compared with healthy controls (ie, those with no ACL reconstruction). A second hypothesis was that quadriceps strength symmetry would predict single-leg drop-landing symmetry in individuals who have undergone ACL reconstruction.

Study Design: Controlled laboratory study.

Methods: The study entailed a total of 103 participants (age, 17.4 years) at the time of return to sport after ACL reconstruction and 47 control participants (age, 17.0 years). The quadriceps index (QI) was calculated for isometric quadriceps strength, which was then used to divide the ACL reconstruction participants into high-quadriceps (QI ?90%; n = 52) and low-quadriceps (QI <85%; n = 41) subgroups. Biomechanical data were collected by use of 3-dimensional motion analysis during a single-leg drop-landing task. The LSI was calculated for kinematic and kinetic sagittal-plane variables of interest during landing. Group differences were compared by use of 1-way analysis of variance and linear regression analyses (? < .05).

Results: Both the low- and high-quadriceps groups demonstrated greater limb asymmetry during landing compared with the control group in knee flexion excursion (mean LSI ± SD: low quadriceps, 85.8% ± 15.5% [P < .001]; high quadriceps, 94.2% ± 15.6% [P = .019]; control, 102.7% ± 14.1%), peak trunk flexion angle (low quadriceps, 129.2% ± 36.6% [P < .001]; high quadriceps, 110.5% ± 22.6% [P = .03]; control, 95.5% ± 26.2%), and peak knee extension moment (low quadriceps, 79.5% ± 25.2% [P < .001]; high quadriceps, 89.9% ± 19.8% [P = .005]; control, 102.2% ± 10.9%). Compared with the high-quadriceps group, the low-quadriceps group also demonstrated greater asymmetry during landing in knee flexion excursion (P = .026), peak trunk flexion angle (P = .006), and peak knee extension moment (P = .034). In the ACL reconstruction group, quadriceps strength symmetry predicted symmetry in knee flexion excursion, peak trunk flexion, and peak knee extension moment (all P < .001) and predicted symmetry in peak trunk flexion angle (P < .001) after controlling for graft type, knee-related pain, function with activities of daily living, and sport function.

Conclusion: At the time of return to sport, athletes who had undergone ACL reconstruction, including those in both the high- and low-quadriceps groups, demonstrated asymmetry during a single-leg drop-landing task compared with controls. Compensations included increased trunk flexion, decreased knee flexion excursion, and decreased knee extension moments on the involved limb. In addition, individuals in the low-quadriceps group demonstrated greater movement asymmetry compared with individuals in the high-quadriceps group.

Clinical Relevance: Restoration of symmetric quadriceps strength after ACL reconstruction is associated with more symmetric mechanics during a single-leg drop-landing movement. However, this appears to be multifactorial, as the high-quadriceps group also demonstrated landing asymmetries. Restoration of symmetric quadriceps strength may improve postoperative athletic participation; however, future study is warranted.

… New research has identified the true cause of exercise-associated muscle cramps and led to a promising new solution.

One of the leaders in neuroscience is Dr. Rod MacKinnon, a Nobel Prize-winner and an avid sea kayaker who can relate to athletes like Cathy on an experiential level. MacKinnon became interested in finding a reliable way to prevent muscle cramps when a cramping episode ruined one of his sea kayaking adventures even though, like Cathy, he thought he had done everything possible to avoid the problem.

MacKinnon’s subsequent investigations led him to the realization that muscles cramp during exercise when fatigue causes the nerve that delivers movement commands from the brain to a muscle to become hyper-excited, sending the muscle into involuntary contraction.

Background: The Fédération Internationale de Football Association (FIFA) 11+ program has been shown to be an effective injury prevention program in the female soccer cohort, but there is a paucity of research to demonstrate its efficacy in the male population.

Hypothesis: To examine the efficacy of the FIFA 11+ program in men’s collegiate United States National Collegiate Athletic Association (NCAA) Division I and Division II soccer.

Study Design: Randomized controlled trial; Level of evidence, 1.

Methods: Before the commencement of the fall 2012 season, every NCAA Division I and Division II men’s collegiate soccer team (N = 396) was solicited to participate in this research study. Human ethics review board approval was obtained through Quorum Review IRB. Sixty-five teams were randomized: 34 to the control group (CG; 850 players) and 31 to the intervention group (IG; 675 players). Four teams in the IG did not complete the study, reducing the number for analysis to 61. The FIFA 11+ injury prevention program served as the intervention and was utilized weekly. Athlete-exposures (AEs), compliance, and injury data were recorded using a secure Internet-based system.

Results: In the CG, 665 injuries (mean ± SD, 19.56 ± 11.01) were reported for 34 teams, which corresponded to an incidence rate (IR) of 15.04 injuries per 1000 AEs. In the IG, 285 injuries (mean ± SD, 10.56 ± 3.64) were reported for 27 teams, which corresponded to an IR of 8.09 injuries per 1000 AEs. Total days missed because of injury were significantly higher for the CG (mean ± SD, 13.20 ± 26.6 days) than for the IG (mean ± SD, 10.08 ± 14.68 days) (P = .007). There was no difference for time loss due to injury based on field type (P = .341).

Conclusion: The FIFA 11+ significantly reduced injury rates by 46.1% and decreased time loss to injury by 28.6% in the competitive male collegiate soccer player (rate ratio, 0.54 [95% CI, 0.49-0.59]; P < .0001) (number needed to treat = 2.64).

We’re fighting a losing battle is a phrase that is thrown around far too frequently. It’s meant to show despair but also to inspire a change of direction. When it comes to performance enhancing drug use in sport, sadly this cliche phrase is applicable. We are losing a fight that needs to be won, if not only for the sake of parents and coaches of young athletes everywhere who need to be able to look into their young athletes eyes dreaming of Olympic glory and tell them that it’s possible.

Traditionally, we have fought the war on performance enhancing drugs (PEDs) using a testing based model to try to catch athletes. More recently, the use of investigations and whistle blowers has brought about the catching of drug cheats.

However, If the Lance Armstrong or Marion Jones’ of the world have taught us anything it’s that passing a drug test means little except that you are smart enough to not make a blatant mistake. In a BBC documentary I was a part of, a journalist ordered EPO from China and by simply searching on the Internet, took enough EPO to see massive performance benefits while avoiding raising any suspicion on the latest in anti-doping science, the athlete blood passport.

Earlier this month, the Drug Enforcement Administration announced that it had busted 16 underground labs and seized 134,000 steroid tablets and pills, 8,200 liters of injectable steroid liquid (that’s 140 kegs worth), and 1,400 pounds of the raw powder from which steroids are made. In Arizona alone, four labs and 150,000 doses of all types were taken by DEA agents in an undercover operation that spanned 20 states and four foreign countries. … One reasonable inference from the amount of steroids seized might be: there must be a heck of a lot of athletes who are doping. And that’s true.

Young runners are different than you and me. They have more speed. And to achieve that swiftness, they use certain leg muscles quite differently than runners past age 50 do, according to a new study of runners’ strides at different ages. The study also intimates that many of us might be able to reinvigorate our flagging pace with the right type of strength training.

Science, competitive records and lived experience all show that runners slow with advancing age, even the great ones. The current world marathon record for men, for instance, 2:02:57, was blazed by a 30-year-old, and is nearly an hour faster than the world record of 2:54:48 for the 70- to 75-year-old age group, which was set by Ed Whitlock, a Canadian. He later ran the world record for the 80- to 85-year-old age group with a 3:15:54 clocking that, although blisteringly fast by my standards, was more than 20 minutes slower than his septuagenarian self.

… The physiological background of HRV is complex and affected by circulating hormones, baroreceptors, chemoreceptors and muscle afferents. An important factor which influences HRV is respiratory sinus arrhythmia – the natural variation in heart rate (HR) that occurs during breathing5. During inspiration, HR increases whereas expiration is characterised by a decrease in HR. The autonomic nervous system (ANS) through sympathetic (SNS) and parasympathetic (PNS) pathways regulates the function of internal organs and the cardiovascular system1,5. Sympathetic activity increases cardiac contractility and HR, whereas parasympathetic (vagal) stimulation reduces HR5,9. Any source of stress (psychological, physical or illness) will provoke disturbance in the ANS and consequently in HRV. The long-term presence of imbalance between sympathetic and parasympathetic tone can impair the performance of athletes.

The analysis of HRV in sport has become established and recognised in the past 2 decades as a non-invasive method for evaluation of the body’s reaction to training loads, recovery methods and overtraining syndrome (OTS). In the last 5 years, innovations in wireless technology have significantly increased the number of devices on the market which are using HRV indices to control and manage the training processes of athletes.

… West German football was at the peak of its powers in the mid-70s but Weise noted something odd. Why were the youth teams not winning any trophies? “We were by far the biggest football association in Europe but we didn’t even make it to finals in the youth tournaments. I believe that was down to politics. The DFB [German Football Association] was a huge machine then, with representatives from all the regional federations. They wanted to see their players getting picked. That meant that better players from the bigger states were left behind because somebody, somewhere, insisted on the inclusion of his guy.”

After his appointment as youth coach by the German FA in 1978, Weise set out to find talents in places where others hadn’t bothered to look. He went to see hundreds of youth games all over the country, turning up unannounced at training sessions. “Sometimes I looked at a player five times. I wrote everything down in a large file.” He carefully takes it off the shelf. The German FA have plans to include it in their newly built football museum in Dortmund, he says.

Seeing several players from the same state on a U.S. national team roster isn’t surprising when they hail from California, which has the nation’s largest population, nearly 40 million, and year-round soccer-playing weather.

But Colorado? That’s a state of 5.6 million with a real winter.

Yet the current U.S. U-17 girls national team’s 26-player roster includes six players from Colorado.

Here we ask you to identify which tool was used to produce the following 18 charts: 4 were done with R, 3 with SPSS, 5 with Excel, 2 with Tableau, 1 with Matlab, 1 with Python, 1 with SAS, and 1 with JavaScript. The solution, including for each chart a link to the webpage where it is explained in detail (many times with source code included) can be found here. You need to be a DSC member to access the page with the solution: you can sign-up here.

How do you score? Would this be a good job interview question?

… The first step in setting up a true speed test is to appreciate that you need enough distance to measure an athlete’s maximal velocity. Time after time I watch coaches use timing gates or cameras to time speed, yet they don’t measure the required acceleration zone or standardize the process. The most important quality of a test is that it can be repeated, with the setup as similar procedurally as possible each time. I am horrified when major programs don’t replicate seasonal testing properly. If not, the data is nearly useless because it’s lost the opportunity for year-to-year comparisons of an athlete’s ability. The truth is that a good maximal velocity test is not difficult to perform.

Almost a decade ago, Ross Tucker and his colleagues at the University of Cape Town published a striking graph showing the average pacing strategies in men’s middle- and long-distance track world records over the past century.

The patterns are remarkably consistent. In the 5,000 and 10,000 meters, the first and last parts of the race are the fastest—of the 66 records set in the modern era in these two events, only once (Paul Tergat in 1997) has any kilometer other than the first or last been the fastest.

Way back in February, in Bradenton, Fla., Clint Hurdle said the Pirates intended to implement a strategy of more often resting players, believing it would lead to better efficiency on the field.

Hurdle remained committed to the less-is-more plan months later, during game No. 142 on Tuesday.