Applied Sports Science newsletter – May 30, 2017

Applied Sports Science news articles, blog posts and research papers for May 30, 2017


Chris Archer a proponent of ‘mindfulness,’ the new big performance edge for athletes, R.J. Anderson from

Tampa Bay Rays ace Chris Archer did more than set a new franchise record when he lost 19 games last season — he tied the 30-team era’s mark for the second-most defeats suffered in a single season. (Mike Maroth, infamous for his 21-loss effort in 2003, retains the dubious honor of pacing the field.) Of course win-loss record carries little predictive value, and speaks more to a confluence of variables than the individual pitcher in question. But it’s fair to write Archer was (and is) too talented to merit the statistical embarrassment he endured in 2016.

Fortunately for Archer and the Rays, it’s also fair to write that few players appear better equipped than he is to rebound from such indignity. That’s in part because Archer practices mindfulness — a technique peak performance coach and author Howard Falco calls “the next edge in sports.” Falco is relevant here because his book I AM no less than inspired Archer and informed his ways.


‘Science can’t measure hard work, desire, heart’

the mixed zone, Goldie Sayers from

Goldie Sayers retired from athletics earlier this year after nearly two decades at the sharp end of a sport in which she won an Olympic bronze medal and broke the British javelin record. Here she passes on the wisdom received through experience in ‘What I’ve Learnt From 20 Years of International Sport’


The ‘why’ of strength and conditioning

AUT Millennium News, Jamie Douglas from

Figuring out why you should exercise may be the most important step in your health and fitness journey. Motivation can be a difficult thing to pin down, some weeks we have an insatiable drive to exercise (first week of the year, anyone?) and others we can barely be dragged into the gym. This isn’t uncommon, but ideally we want to get to the stage where showing up becomes unconditional. This is when we’ve found our ‘why’. There is a large body of research into motivation which can not only can give us a framework to understand our personal motivational state but also insight into how to improve it. The self-determination theory from the world of psychology is a powerful tool that can be used to explain motivation and how we can instigate long-term behaviour change.


Children’s Brain Images Show How Cognitive Control Increases with Age

Psych Central News, Traci Pedersen from

As a child’s brain develops, it becomes more segregated into specialized units, but at the same time, more integrated as a whole due to stronger “hub” connections. These well-defined, networked brain structures are directly related to the healthy development of executive functions, such as the ability to control impulses, stay organized, and make decisions.

In a new study, published in the journal Current Biology, researchers were able to map the changes in the brain that underlie these improvements in executive function. The findings could also lead to the identification of biomarkers of abnormal brain development that could predict a person’s risk for psychosis and major mood disorders.


The match-to-match variation of match-running in elite female soccer. – Journal of Science and Medicine in Sport

Journal of Science & Medicine in Sport from


The purpose of this study was to examine the match-to-match variation of match-running in elite female soccer players utilising GPS, using full-match and rolling period analyses.

Longitudinal study.

Elite female soccer players (n = 45) from the same national team were observed during 55 international fixtures across 5 years (2012-2016). Data was analysed using a custom built MS Excel spreadsheet as full-matches and using a rolling 5-min analysis period, for all players who played 90-min matches (files = 172). Variation was examined using co-efficient of variation and 90% confidence limits, calculated following log transformation.

Total distance per minute exhibited the smallest variation when both the full-match and peak 5-min running periods were examined (CV = 6.8-10%). Sprint-efforts were the most variable during a full-match (CV = 53%), whilst high-speed running per minute exhibited the greatest variation in the post-peak 5-min period (CV = 143%). Peak running periods were observed as slightly more variable than full-match analyses, with the post-peak period very-highly variable. Variability of Accelerations (CV = 17%) and Player Load (CV = 14%) was lower than that of high-speed actions. Positional differences were also present, with centre backs exhibiting the greatest variation in high-speed movements (CV = 41-65%).

Practitioners and researchers should account for within player variability when examining match performances. Identification of peak running periods should be used to assist worst case scenarios. Whilst micro-sensor technology should be further examined as to its viable use within match-analyses.


Intensity- and Duration-Based Options to Regulate Endurance Training

Frontiers in Physiology from

The regulation of endurance training is usually based on the prescription of exercise intensity. Exercise duration, another important variable of training load, is rarely prescribed by individual measures and mostly set from experience. As the specific exercise duration for any intensity plays a substantial role regarding the different kind of cellular stressors, degree, and kind of fatigue as well as training effects, concepts integrating the prescription of both intensity and duration within one model are needed. An according recent approach was the critical power concept which seems to have a physiological basis; however, the mathematical approach of this concept does not allow applying the three zones/two threshold model of metabolism and its different physiological consequences. Here we show the combination of exercise intensity and duration prescription on an individual basis applying the power/speed to distance/time relationship. The concept is based on both the differentiation of intensities by two lactate or gas exchange variables derived turn points, and on the relationship between power (or velocity) and duration (or distance). The turn points define three zones of intensities with distinct acute metabolic, hormonal, and cardio-respiratory responses for endurance exercise. A maximal duration exists for any single power or velocity such as described in the power-duration relationship. Using percentages of the maximal duration allows regulating fatigue, recovery time, and adaptation for any single endurance training session. Four domains of duration with respect to induced fatigue can be derived from maximal duration obtained by the power-duration curve. For any micro-cycle, target intensities and durations may be chosen on an individual basis. The model described here is the first conceptual framework of integrating physiologically defined intensities and fatigue related durations to optimize high-performance exercise training. [full text]


High-speed running and sprinting as an injury risk factor in soccer: Can well-developed physical qualities reduce the risk?

Journal of Science & Medicine in Sport from

This study investigated the association between high-speed running (HSR) and sprint running (SR) and injuries within elite soccer players. The impact of intermittent aerobic fitness as measured by the end speed of the 30-15 intermittent fitness test (30–15 VIFT) and high chronic workloads (average 21-day) as potential mediators of injury risk were also investigated.

Observational Cohort Study.

37 elite soccer players from one elite squad were involved in a one-season study. Training and game workloads (session-RPE × duration) were recorded in conjunction with external training loads (using global positioning system technology) to measure the HSR (>14.4 km h−1) and SR (>19.8 km h−1) distance covered across weekly periods during the season. Lower limb injuries were also recorded. Training load and GPS data were modelled against injury data using logistic regression. Odds ratios (OR) were calculated with 90% confidence intervals based on 21-day chronic training load status (sRPE), aerobic fitness, HSR and SR distance with these reported against a reference group.

Players who completed moderate HSR (701–750-m: OR: 0.12, 90%CI: 0.08–0.94) and SR distances (201–350-m: OR: 0.54, 90%CI: 0.41–0.85) were at reduced injury risk compared to low HSR (≤674-m) and SR (≤165-m) reference groups. Injury risk was higher for players who experienced large weekly changes in HSR (351–455-m; OR: 3.02; 90%CI: 2.03–5.18) and SR distances (between 75–105-m; OR: 6.12, 90%CI: 4.66–8.29). Players who exerted higher chronic training loads (≥2584 AU) were at significantly reduced risk of injury when they covered 1-weekly HSR distances of 701 to 750 m compared to the reference group of <674 m (OR = 0.65, 90% CI 0.27–0.89). When intermittent aerobic fitness was considered based on 30–15 VIFT performance, players with poor aerobic fitness had a greater risk of injury than players with better-developed aerobic fitness. Conclusions

Exposing players to large and rapid increases in HSR and SR distances increased the odds of injury. However, higher chronic training loads (≥2584 AU) and better intermittent aerobic fitness off-set lower limb injury risk associated with these running distances in elite soccer players.


Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse Cohort

Journal of Personalized Medicine from

The ability to measure physical activity through wrist-worn devices provides an opportunity for cardiovascular medicine. However, the accuracy of commercial devices is largely unknown. The aim of this work is to assess the accuracy of seven commercially available wrist-worn devices in estimating heart rate (HR) and energy expenditure (EE) and to propose a wearable sensor evaluation framework. We evaluated the Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn, and Samsung Gear S2. Participants wore devices while being simultaneously assessed with continuous telemetry and indirect calorimetry while sitting, walking, running, and cycling. Sixty volunteers (29 male, 31 female, age 38 ± 11 years) of diverse age, height, weight, skin tone, and fitness level were selected. Error in HR and EE was computed for each subject/device/activity combination. Devices reported the lowest error for cycling and the highest for walking. Device error was higher for males, greater body mass index, darker skin tone, and walking. Six of the devices achieved a median error for HR below 5% during cycling. No device achieved an error in EE below 20 percent. The Apple Watch achieved the lowest overall error in both HR and EE, while the Samsung Gear S2 reported the highest. In conclusion, most wrist-worn devices adequately measure HR in laboratory-based activities, but poorly estimate EE, suggesting caution in the use of EE measurements as part of health improvement programs. We propose reference standards for the validation of consumer health devices ( [full text]


Blood Gets an Upgrade

Massachusetts General Hospital, Proto magazine from

Each year, donors step up to replenish the nation’s blood supply. Depending on volunteers for this critical resource, however, has never been ideal. The units that come in must be screened for diseases—including nascent threats, such as the Zika virus. And what volunteers can supply may not match the demand, especially for people with rare blood-group types and those with conditions that require frequent transfusions (such as sickle cell disease), who can sometimes develop reactions to transfused blood.

Researchers have spent decades searching for a substitute—a form of blood that can be manufactured—with limited success. This year, however, the United Kingdom’s National Health Service Blood and Transplant (NHSBT) organization will sponsor a clinical trial to test a mini-transfusion of red blood cells made from stem cells.


The science behind safe tackling

University of Capetown News from

Tackles are made almost every 30 seconds in rugby matches, often at high-impact, causing half of rugby-related injuries to both forwards and backs. But evidence-based tackle-contact training can make a difference at all levels of the game, says UCT sports scientist Dr Sharief Hendricks.


Twins emphasizing nutrition throughout their organization, Mike Berardino from

Hector Lujan noticed the difference a couple of weeks back when the local booster club held its annual pizza party for the Cedar Rapids Kernels.

Amid an organization-wide emphasis on better nutrition and healthy food choices, two dozen aspiring young ballplayers in the Twins system weren’t quite sure how to act.

“Everyone just seemed really composed and was just keeping their cool not to go crazy,” said Lujan, a hard-throwing reliever for the Class A team. “It was still fun. The gathering side of it was good, but it wasn’t an ambush like it usually would be.”


Branched-chain amino acid ingestion stimulates muscle myofibrillar protein synthesis following resistance exercise in humans

Frontiers in Physiology from

The ingestion of intact protein or essential amino acids (EAA) stimulates mechanistic target of rapamycin complex-1 (mTORC1) signaling and muscle protein synthesis (MPS) following resistance exercise. The purpose of this study was to investigate the response of myofibrillar-MPS to ingestion of branched-chain amino acids only (i.e., without concurrent ingestion of other EAA, intact protein or other macronutrients) following resistance exercise in humans. Ten young (20.1 ± 1.3 y), resistance-trained men completed two trials, ingesting either 5.6g branched-chain amino acid (BCAA) or a placebo (PLA) drink immediately after resistance exercise. Myofibrillar-MPS during exercise recovery was measured with a primed, constant infusion of L-[ring13C6] phenylalanine and collection of muscle biopsies pre and 4h post drink ingestion. Blood samples were collected at time-points before and after drink ingestion. Western blotting was used to measure the phosphorylation status of mTORC1 signaling proteins in biopsies collected pre, 1h- and 4h-post drink. The percentage increase from baseline in plasma leucine (300 ± 96%), isoleucine (300 ± 88%) and valine (144 ± 59%) concentrations peaked 0.5h-post drink in BCAA. A greater phosphorylation status of S6K1Thr389 (P=0.012) and PRAS40 (P=0.043) was observed in BCAA than PLA at 1h post drink ingestion. Myofibrillar-MPS was 22% higher (P=0.012) in BCAA (0.110 ± 0.009 %/h) than PLA (0.090 ± 0.006 %/h). Phenylalanine Ra was ~6% lower in BCAA (18.00 ± 4.31 μmol·kgBM-1) than PLA (21.75 ± 4.89 μmol·kgBM-1; P=0.028) after drink ingestion. We conclude that ingesting branched-chain amino acids alone increases the post-exercise stimulation of myofibrillar-MPS and phosphorylation status mTORC1 signaling.


What Made These Players the Most Valuable Picks in This Year’s NFL Draft?

OZY, The Huddle, Michelle Bruton from

… Another recent tweak to evaluating talent: Athleticism now overrides atypical body types. The example Hirschhorn gives is the Arizona Cardinals’ 2017 draft pick, edge rusher Haason Reddick. At 6’1” and 237 pounds, the former Temple Owl doesn’t necessarily fit the prototypical body types for 3-4 outside linebackers or 4-3 defensive ends. But scouts love Reddick’s athleticism, which he displayed at the NFL Combine in February. He tested through the roof, including a 4.52 40-yard dash, the fastest among his position group. Reddick, who would have gone in the mid-rounds a few years ago for being undersized, was drafted No. 13 overall.


US soccer gets a boost from blossoming second-tier squads in the USL

CNBC, James Justice from

… “The USL is now kind of built to be a funnel for players to get somewhere, whether that’s MLS [or] Mexico. It’s serving that purpose now, so they have a meaning behind what they do,” said Antony Merced, a follower of the league since 2010 and co-host of the “Raising Bulls” podcast devoted to Red Bulls II. He argued the USL found its identity when partnering with MLS.

Giving players a professional environment who may have lacked playing opportunities has been a huge step for U.S. soccer as a whole. The MLS used to offer a reserve league for its players that were on the roster, but were rarely featured on match day. During those days, matches were held sporadically and frequently canceled, while games functioned more as scrimmages than professional matches.


[1705.08079] Effective injury prediction in professional soccer with GPS data and machine learning

arXiv, Statistics > Machine Learning; Alessio Rossi, Luca Pappalardo, Paolo Cintia, Marcello Iaia, Javier Fernandez, Daniel Medina from

Injuries have a great impact on professional soccer, due to their large influence on team performance and the considerable costs of rehabilitation for players. Existing studies in the literature provide just a preliminary understanding of which factors mostly affect injury risk, while an evaluation of the potential of statistical models in forecasting injuries is still missing. In this paper, we propose a multidimensional approach to injury prediction in professional soccer which is based on GPS measurements and machine learning. By using GPS tracking technology, we collect data describing the training workload of players in a professional soccer club during a season. We show that our injury predictors are both accurate and interpretable by providing a set of case studies of interest to soccer practitioners. Our approach opens a novel perspective on injury prevention, providing a set of simple and practical rules for evaluating and interpreting the complex relations between injury risk and training performance in professional soccer.


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