Applied Sports Science newsletter – August 14, 2020

For New Orleans Pelicans rookie Zion Williamson, it’s time to turn the page to next season and focus on getting better — with his game and his body.

“I’ll talk to my coaches and see what I need to do better from their point of view,” Williamson said Thursday morning. “Talk to my player development coaches as well, see what I need to do better from their point of view. Just work on every part of my game and work on getting my body where it needs to be.”

This study aimed to analyse the effect of playing surface temperature on muscular and thermal response to a repeated-sprint ability (RSA) test in football players. Thirty-two male football players (23 ± 5 years; 1.77 ± 0.06 m; 71.2 ± 6.7 kg) from two squads of a third-division football club participated in the study. An RSA test was carried out at a high surface temperature (45.34 ± 2.53 °C) and low surface temperature (27.21 ± 2.17 °C). Before and after this test, the muscular response of the players was assessed through tensiomyography and thermograms. The results revealed that performance in the RSA test particularly increased at a higher surface temperature, especially in the first 5 m of the 30 m sprint test. While a reduction in maximal radial displacement (Dm) in the biceps femoris post-RSA was observed at lower surface temperatures, a higher temperature on the thigh, hamstring and calf was found in the higher surface temperature group. In conclusion, higher surface temperatures had an influence on players’ thermal and tensiomyographic profile and improved performance in their repeated-sprint ability. These results suggest a need for coaches and players to be aware of these parameters to ensure adequate functionality and safety of the playing surface. [full text]

Purpose

This study examined whether additional external load during the eccentric phase of lower limb strength training exercises led to greater adaptations in knee extensor strength, muscle architecture, and patellar tendon properties than traditional concentric–eccentric training in already-trained men.
Methods

Twenty-eight men accustomed to strength training were randomized to undertake 10 weeks of supervised traditional (TRAD) or accentuated eccentric loading (AEL) or continue their habitual unsupervised (CON) strength training. TRAD and AEL trained 2∙week−1 with a six-repetition maximum (RM) session and a ten-RM session. TRAD used the same external load in both concentric and eccentric phases, while AEL used 40% greater load during the eccentric than concentric phase. Tests were performed at pre- and post-training, including: maximum unilateral isokinetic (30°·s−1) concentric, eccentric and isometric torques by isokinetic dynamometry, unilateral isometric ramp contractions with muscle–tendon ultrasound imaging to measure tendon stiffness and hysteresis, and resting vastus lateralis and medialis fascicle angle and length measured by extended-field-of-view ultrasound.
Results

After training, both TRAD and AEL significantly increased maximum concentric and isometric torque (p < 0.05), but only AEL increased eccentric torque (AEL: + 10 ± 9%, TRAD: + 4 ± 9%) and vastus lateralis (AEL: + 14 ± 14%, TRAD: + 1 ± 10%) and medialis (AEL: + 19 ± 8%, TRAD: + 5 ± 11%) fascicle length. Conclusion

Both TRAD and AEL increased maximum knee extensor strength but only AEL increased VL and VM fascicle length. Neither training program promoted changes in fascicle angle or changes in patellar tendon properties in our already-trained men. [full text]

This investigation examined match play physical performance across a professional football season using a multi-camera computerized tracking system. A linear mixed-effects model, controlling for situational and contextual variables, identified decreases in team average total distance (TD): season quarter 1 (Q1) (11047 m) > season quarter 2 (Q2) (10473 m) (P=0.002; ES=Small), season quarter 3 (Q3) (10449 m) (P<0.001; ES=Moderate) and season quarter 4 (Q4) (10385 m) (P<0.001; ES=Moderate); work rate (WR): Q1 (115 m/min) > Q3 (108 m/min) (P<0.001; ES=Moderate), Q4 (107 m/min) (P<0.001; ES=Moderate); Q2 (109 m/min) > Q4 (107 m/min) (P=0.003; ES=Small); high-speed running distance (HSR): Q1 (1051 m) > Q2 (813 m) (P=0.006; ES=Small); number of high-speed runs (NHSR): Q1 (87) > Q2 (65) (P<0.001; ES=Small), Q3 (64) (P=0.002; ES=Small); sprint distance (SD): Q1 (202 m) > Q4 (130 m) (P<0.001; ES=Moderate), Q2 (179 m) > Q3 (165 m) (P=0.035; ES=Small), Q4 (130 m) (P<0.001; ES=Moderate) and number of sprints (NS): Q1 (20.4) > Q3 (10.2) (P<0.001; ES=Moderate), Q4 (8.3) (P<0.001; ES=Large); Q2 (14.9) > Q3 (10.2) (P<0.001; ES=Moderate), Q4 (8.3) (P<0.001; ES=Large). Within-position changes were observed for WR: Q1 (122 m/min) > Q4 (113 m/min) (P=0.002; ES=Large) in central midfielders and for NS: Q1 > Q3 in wide defenders (21.7 vs 10.8) (P=0.044; ES=Large) and central midfielders (18.1 vs 8.3) (P=0.002; ES=Large); Q1 > Q4 in central defenders (13.1 vs 5.3) (P=0.014; ES=Large), wide defenders (21.6 vs 7.1) (P<0.001; ES=Very Large), central midfielders (18.1 vs 8.5) (P=0.005; ES=Large) and wide midfielders (20.8 vs 12.2) (P=0.012; ES=Large); Q2 > Q3 in central midfielders (16.9 vs 8.3) (P=0.002; ES=Large) and Q2 > Q4 in wide defenders (16.3 vs 7.1) (P=0.005; ES=Very Large), central midfielders (16.9 vs 8.5) (P=0.004; ES=Large) and wide midfielders (20.8 vs 12.2) (P=0.007; ES=Large). Match-play physical performance reduced across the competitive season. The most notable reductions were observed in wide defenders, central midfielders and wide midfielders in sprint performance indices.

Background

This article sets the scene for a critique of the research underpinning two common clinical assumptions: (1) training workload is a key factor influencing sports injury risk, and (2) it can be manipulated to reduce injury risk. In this summary we address why it is important for clinicians to critically evaluate the evidence behind research conclusions.
Clinical Question

Has research been designed and conducted well enough to help clinicians answer the questions ‘what is the relationship between training workload and sports injury risk?’ and ‘can the metrics based on training workload be used to decrease the injury risk?’
Key Findings

In the past decade, many sports injury researchers have developed new measures of exposure based on internal and external training workload to study the relationship between training load and injury. Some of these metrics may have been embraced by researchers and clinicians because (1) they are apparently supported by the scientific literature, (2) they are simple to calculate and use (averages and their ratio), and (3) there is an apparent reasonable rationale/narrative to support using workload metrics. However, (intentional or unintentional) questionable research practices and over-interpretation of research results undermines the trustworthiness of research in the training load-sports injury field.
Clinical Application

Clinicians should always aim to critically examine the credibility of the evidence behind a research conclusion before implementing research findings in practice. Something that initially looks promising and inviting might not be as revolutionary or useful as one first anticipated.

When we dream, our brains are filled with noisy electrical activity that looks nearly identical to that of the awake brain.

But UC Berkeley researchers have pulled a signal out of the noise that uniquely defines dreaming, or REM sleep, potentially making it easier to monitor people with sleep disorders, as well as unconscious coma patients or those under anesthesia.

If you’ve ever finished a workout and found yourself disappointed not to be drenched in sweat, you’re not alone — many people consider sweating profusely to be a sign of vigorous exercise.

But you don’t need to sweat to get a good workout, according to Dr. Lindsay Baker, sweat expert and principal scientist at the Gatorade Sports Science Institute.

Baker told Insider that many factors can influence overall sweatiness, and research on how and why people sweat can offer valuable insight into how the human body adapts to exercise and recovers afterward.

… the NTU team created a ‘bioinspired’ data fusion system that uses skin-like stretchable strain sensors made from single-walled carbon nanotubes, and an AI approach that resembles the way that the skin senses and vision are handled together in the brain.

The NTU scientists developed their bio-inspired AI system by combining three neural network approaches in one system: they used a ‘convolutional neural network’, which is a machine learning method for early visual processing, a multilayer neural network for early somatosensory information processing, and a ‘sparse neural network’ to ‘fuse’ the visual and somatosensory information together.

The result is a system that can recognise human gestures more accurately and efficiently than existing methods.

In our blog, we will explain why and how we did our study, and what makes it different from previous systematic reviews on treatments for Achilles tendinopathy. This large project took more than two years to complete and was funded by the Dutch government as part of the process to create a clinical management guideline.

https://t.co/BygaEfEsLE?amp=1

Background Lateral ankle sprains are common in indoor sports. High shoe–surface friction is considered a risk factor for non-contact lateral ankle sprains. Spraino is a novel low-friction patch that can be attached to the outside of sports shoes to minimise friction at the lateral edge, which could mitigate the risk of such injury. We aimed to determine preliminary effectiveness (incidence rate and severity) and safety (harms) of Spraino to prevent lateral ankle sprains among indoor sport athletes.

Methods In this exploratory, parallel-group, two-arm pilot randomised controlled trial, 510 subelite indoor sport athletes with a previous lateral ankle sprain were randomly allocated (1:1) to Spraino or ‘do-as-usual’. Allocation was concealed and the trial was outcome assessor blinded. Match and training exposure, number of injuries and associated time loss were captured weekly via text messages. Information on harms, fear-of-injury and ankle pain was also documented.

Results 480 participants completed the trial. They reported a total of 151 lateral ankle sprains, of which 96 were categorised as non-contact, and 50 as severe. All outcomes favoured Spraino with incidence rate ratios of 0.87 (95% CI 0.62 to 1.23) for all lateral ankle sprains; 0.64 (95% CI 0.42 to 0.98) for non-contact lateral ankle sprains; and 0.47 (95% CI 0.25 to 0.88) for severe lateral ankle sprains. Time loss per injury was also lower in the Spraino group (1.8 vs 2.8 weeks, p=0.014). Six participants reported minor harms because of Spraino.

Conclusion Compared with usual care, athletes allocated to Spraino had a lower risk of lateral ankle sprains and less time loss, with only few reported minor harms.

Purpose
To provide an overview of the injuries suffered by Women’s National Basketball Association (WNBA) athletes and to analyze the demographic data, injury rates, and games missed as a result of individual injuries.
Methods
Using publicly available data on WNBA player’s injury history, we generated a database cataloguing the quantity, location, frequency, and longitudinal impact of injuries sustained during the WNBA regular season from 2015 to 2019. We analyzed the data using SPSS-25 data manipulation software to assess the number of injuries per athletic exposure.
Results
Lower-extremity injuries (n = 143, 73%) were the most common injury by body area and resulted in the greatest number of games missed (n = 1189, 88%). Lateral ankle sprains were the most frequent injury (n = 39, 20%), with a rate of 1.19 injuries per 1000 athletic exposures. Torn anterior cruciate ligaments (n = 18, 9.2%) were the most devastating, resulting in the greatest number of games missed (n=376, 28%).
Conclusions
Our findings corroborate previous notions that lower-extremity injuries are the greatest source of injury in this population. Ankle injuries were the most frequent injury reported by pathology, while knee injuries carried the most long-term impact on games missed due to injury. [full text]

A career in professional football may yield an array of health benefits that extend beyond playing years: NFL players engage in vigorous training, tend to be more educated than other men in the U.S. and have higher median incomes than most fellow Americans — all factors associated with better overall health.

But new research from Harvard Medical School and the Harvard T.H. Chan School of Public Health suggests that even these advantages may not be enough to neutralize persistent gaps in health outcomes among Black, white, and players of other racial backgrounds.

Purpose

This review provides an overview of the current knowledge of the nutritional strategies to treat the signs and symptoms related to EIMD. These strategies have been organized into the following sections based upon the quality and quantity of the scientific support available: (1) interventions with a good level of evidence; (2) interventions with some evidence and require more research; and (3) potential nutritional interventions with little to-no-evidence to support efficacy.
Method

Pubmed, EMBASE, Scopus and Web of Science were used. The search terms ‘EIMD’ and ‘exercise-induced muscle damage’ were individually concatenated with ‘supplementation’, ‘athletes’, ‘recovery’, ‘adaptation’, ‘nutritional strategies’, hormesis’.
Result

Supplementation with tart cherries, beetroot, pomegranate, creatine monohydrate and vitamin D appear to provide a prophylactic effect in reducing EIMD. B-hydroxy B-methylbutyrate, and the ingestion of protein, BCAA and milk could represent promising strategies to manage EIMD. Other nutritional interventions were identified but offered limited effect in the treatment of EIMD; however, inconsistencies in the dose and frequency of interventions might account for the lack of consensus regarding their efficacy.
Conclusion

There are clearly varying levels of evidence and practitioners should be mindful to refer to this evidence-base when prescribing to clients and athletes. One concern is the potential for these interventions to interfere with the exercise-recovery-adaptation continuum. Whilst there is no evidence that these interventions will blunt adaptation, it seems pragmatic to use a periodised approach to administering these strategies until data are in place to provide and evidence base on any interference effect on adaptation.

What was unthinkable just five years ago for pitchers is not just the norm but also the way forward.