Postactivation performance enhancement: Does conditioning one arm augment performance in the other?

The purpose was to determine whether postactivation performance enhancement is specific to the muscle being conditioned or if it is also observed within the homologous muscles of the contralateral limb (after accounting for the warm-up and random error). We also investigated whether this differed based on training status or muscle size. One hundred seven participants (75 untrained; 32 trained) participated in four sessions. Visit 1 included baseline measurements and familiarization. Visits 2-4 included the completion of one of the three experimental conditions: (a) control, (b) same side and (c) crossover completed in a randomized order. The control condition completed all testing except for the conditioning contraction. The same side condition completed the conditioning contraction on the same side as the strength test. The crossover condition completed the conditioning on the arm opposite to the strength test. The variable of interest was the change from baseline in isokinetic strength. Our analysis indicated that of the hypotheses compared, the posterior probabilities (posterior probability of 0.506) favoured the hypothesis that the effect was local and greatest in those who were resistance trained [mean (SD) of 1.4 (2.2) Nm over the control in those resistance trained]. We found no relationship between muscle size and postactivation performance enhancement. In conclusion, there is an influence of training status pertaining to the postactivation performance enhancement effect but no influence from baseline muscle size. It appears unlikely that the effect is due to a systemic mechanism.

Back-Reflected Performance-Enhanced Flexible Perovskite Photodetectors through Substrate Texturing with Femtosecond Laser

Recently, enhancing the performance of flexible perovskite photodetectors through facile and effective means has gained greater attention. In contrast to typical approaches through modifying light-active materials, we present here a simple but effective design by improving light-matter interactions through near-field optical interference on a back-reflected substrate, whose architecture includes a morphologically flat top surface and a backscattering surface textured with micro/nanostructures by the femtosecond laser direct writing. A CH₃NH₃PbI₃ perovskite film and poly(ethylene terephthalate) are selected as the light-active and base materials, respectively. Under a 1 V bias voltage actuation and 532 nm laser irradiation at an intensity of 10 mW cm^-2, the flexible device exhibits excellent performance in photoresponsivity (47.1 mA W^-1), detectivity (3.7 × 10¹¹ Jones), and on/off ratio (4600). Due to the near-field optical enhancement of the substrate and the strong light-matter interaction, the above performance parameters are enhanced by at least 5 times over a wide spectral range of 220-780 nm. Such enhancement behaviors are independent of active material properties and therefore can be compatible with other operations such as crystalline transformation, doping, and interface modification. Moreover, the alteration of stress distribution on the structured substrate facilitates the bending robustness and stability. These features highlight the potential of back-reflected design in the development of flexible perovskite photoelectric devices, which are especially suitable for large-scale industrial production.

Positive Psychological Coaching Definitions and Models: A Systematic Literature Review

Despite the popularity of the term Positive Psychological Coaching within the literature, there is no consensus as to how it should be defined (framed) or what the components of a positive coaching “model” should include. The aim of this systematic review was to define positive psychological coaching and to construct a clear demarcated positive psychological coaching model based on the literature. A systematic literature review led to the extraction of 2,252 records. All records were screened using specific inclusion/exclusion criteria, which resulted in the exclusion of records based on duplicates (n = 1,232), titles (n = 895), abstracts (n = 78), and criteria violations (n = 23). Twenty-four academic, peer-reviewed publications on positive psychological coaching were included. Data relating to conceptual definitions and coaching models/phases/frameworks were extracted and processed through thematic content analysis. Our results indicate that positive psychological coaching can be defined as a short to medium term professional, collaborative relationship between a client and coach, aimed at the identification, utilization, optimization, and development of personal strengths and resources in order to enhance positive states, traits and behaviors. Utilizing Socratic goal setting and positive psychological evidence-based approaches to facilitate personal growth, optimal functioning, enhanced wellbeing, and the actualization of people's potential. Further, eight critical components of a positive psychological coaching model were identified and discussed. The definition and coaching process identified in this study will provide coaches with a fundamental positive psychological framework for optimizing people's potential.

Neurodiagnostics in Sports: Investigating the Athlete's Brain to Augment Performance and Sport-Specific Skills

Enhancing performance levels of athletes during training and competition is a desired goal in sports. Quantifying training success is typically accompanied by performance diagnostics including the assessment of sports-relevant behavioral and physiological parameters. Even though optimal brain processing is a key factor for augmented motor performance and skill learning, neurodiagnostics is typically not implemented in performance diagnostics of athletes. We propose, that neurodiagnostics via non-invasive brain imaging techniques such as functional near-infrared spectroscopy (fNIRS) will offer novel perspectives to quantify training-induced neuroplasticity and its relation to motor behavior. A better understanding of such a brain-behavior relationship during the execution of sport-specific movements might help to guide training processes and to optimize training outcomes. Furthermore, targeted non-invasive brain stimulation such as transcranial direct current stimulation (tDCS) might help to further enhance training outcomes by modulating brain areas that show training-induced neuroplasticity. However, we strongly suggest that ethical aspects in the use of non-invasive brain stimulation during training and/or competition need to be addressed before neuromodulation can be considered as a performance enhancer in sports.

Effects of Weighted Vest Loading During Daily Living Activities on Countermovement Jump and Sprint Performance

PURPOSE

Wearing a weighted vest (WV) during daily living and training can enhance jump and sprint performance; however, studies examining the efficacy of this method in female populations is limited. This study examined the effect of wearing a WV during daily living and training on countermovement jump (CMJ), change-of-direction, and sprint performance.

METHODS

Trained females were separated into intervention (n = 9) and control (n = 10) groups. The intervention group wore WVs of ∼8% body mass 4 days per week for 8 hours per day (32 h/wk total), and 3 training sessions per week for the first 3 weeks. Subsequently, 3 weeks of regular training without WV stimulus was completed. The control group received no intervention and continued normal training for 6 weeks. Average and best performance was assessed on the single CMJ, four continuous CMJ, t-test change-of-direction drill, and a 25-m sprint at baseline, week 3, and week 6.

RESULTS

No significant interactions or group effects were found. However, significant time main effects revealed increases in average rate of force development during the CMJ from baseline to week 3 (P = .048) and week 6 (P = .013), whereas peak vertical ground reaction force increased during the four continuous CMJ from baseline to week 3 (P = .048) and week 6 (P = .025) for both groups.

CONCLUSIONS

The lower relative WV load used in this study failed to elicit significant improvements in jump and sprint performance in comparison with routine training, or that which have been found in past investigations with elite male athletes completing high-intensity performance tasks with greater WV loads.

Toward Enhanced Teleoperation Through Embodiment

Telerobotics aims to transfer human manipulation skills and dexterity over an arbitrary distance and at an arbitrary scale to a remote workplace. A telerobotic system that is transparent enables a natural and intuitive interaction. We postulate that embodiment (with three sub-components: sense of ownership, agency, and self-location) of the robotic system leads to optimal perceptual transparency and increases task performance. However, this has not yet been investigated directly. We reason along four premises and present findings from the literature that substantiate each of them: (1) the brain can embody non-bodily objects (e.g., robotic hands), (2) embodiment can be elicited with mediated sensorimotor interaction, (3) embodiment is robust against inconsistencies between the robotic system and the operator's body, and (4) embodiment positively correlates to dexterous task performance. We use the predictive encoding theory as a framework to interpret and discuss the results reported in the literature. Numerous previous studies have shown that it is possible to induce embodiment over a wide range of virtual and real extracorporeal objects (including artificial limbs, avatars, and android robots) through mediated sensorimotor interaction. Also, embodiment can occur for non-human morphologies including for elongated arms and a tail. In accordance with the predictive encoding theory, none of the sensory modalities is critical in establishing ownership, and discrepancies in multisensory signals do not necessarily lead to loss of embodiment. However, large discrepancies in terms of multisensory synchrony or visual likeness can prohibit embodiment from occurring. The literature provides less extensive support for the link between embodiment and (dexterous) task performance. However, data gathered with prosthetic hands do indicate a positive correlation. We conclude that all four premises are supported by direct or indirect evidence in the literature, suggesting that embodiment of a remote manipulator may improve dexterous performance in telerobotics. This warrants further implementation testing of embodiment in telerobotics. We formulate a first set of guidelines to apply embodiment in telerobotics and identify some important research topics.

Toward Prevention of Doping in Youth Sport: Cross-Sectional Analysis of Correlates of Doping Tendency in Swimming

Doping is recognized as one of the most important problems in sports, but a limited number of studies have investigated doping problems in youth athletes. This study aimed to evaluate doping tendency (potential doping behavior (PDB)) and correlates of PDB in youth age swimmers. The participants were 241 competitive swimmers (131 females; 15.3 ± 1.1 years of age, all under 18 years old). Variables included predictors and PDB (criterion). Predictors consisted of sociodemographic factors (gender and age), sport-related variables (i.e., experience in swimming and sport achievement), variables explaining coaching strategy and training methodology, consumption of dietary supplements (DS), knowledge about doping, and knowledge about sports nutrition and DS (KSN). In addition to the descriptive statistics and differences between genders, a multinomial regression using PDB as the criterion (negative-, neutral-, or positive-PDB, with a negative-PDB as the reference value) was calculated to define associations between predictors and criterion. With only 71% of swimmers who declared negative-PDB results indicated an alarming figure. Boys with better KSN were more negatively oriented toward positive-PDB (OR: 0.77, 95%CI: 0.60–0.95). In girls, lower competitive achievement was evidenced as a risk factor for neutral-PDB (OR: 0.39, 95%CI: 0.24–0.63). Also, higher neutral-PDB (OR: 0.88, 95%CI: 0.81–0.96) and positive-PDB (OR: 0.90, 95%CI: 0.83–0.99) were identified in girls who began with intensive training in younger age. Because of the alarming figures of PDB, there is an evident need for the development of systematic antidoping educational programs in youth swimming. In doing so, focus should be placed on girls who began intensive training at an earlier age and those who did not achieve high competitive results.

Tuning Methylammonium Iodide Amount in Organolead Halide Perovskite Materials by Post-Treatment for High-Efficiency Solar Cells

In this study, the composition of organic-inorganic perovskite materials is tuned by methylammonium iodide (MAI) post-treatment for high photovoltaic performance. By spin-coating MAI solutions of different concentrations, the amounts of PbI₂ and MAI in perovskite layers are tuned. In perovskites, the removal of PbI₂ through a reaction with MAI decreases the hysteresis in photocurrent density-voltage curves. Further, by treating perovskites with a high-concentration MAI solution, the excess MAI is incorporated into the perovskites. These perovskites with excess MAI show better power conversion efficiencies (of up to 20.7%) than perovskites with excess PbI₂ because of the decrease in trap density. Since the present post-treatment can control perovskite composition without affecting the morphology and crystallinity of the perovskite crystals, this technique would be a useful tool to improve the photovoltaic performance of perovskite solar cells.

Mindfulness-based intervention for tennis players: a quasi-experimental pilot study

Objectives

Mindfulness-based interventions in the context of sports have been shown to result in higher mindfulness scores and improved physiological and psychological parameters. The goal of this pilot study was to investigate the effects of a newly developed seven-session mindfulness-based intervention, mindful ^emotions, on German tennis players.

Methods

The study was conducted in a pre–post test design with an intervention and a control group. Before and after the mindfulness-based stress reduction training the following dependent measurements were assessed: athletic performance (serve accuracy) and psychological performance indicators (mindfulness, stress and competition anxiety).

Results

The results indicate a better performance of the intervention group for the difference scores between post-test and pre-test in one of the sport-related anxiety factors, the concentration disturbances index.

Conclusion

In order to further investigate the effects of this mindfulness-based intervention in competitive sports, additional studies with a larger number of participants have to follow.

Beyond health: medicines, food supplements, energetics and the commodification of self-performance in Maputo

With an increasing range of products in global and local markets, more options are available for individuals to enhance their image and their (cognitive, social and physical) performance. These 'performance consumptions' relate to ideals of well-being and improvement, and are based on constructed desires, expectations and needs that go beyond the (often blurred) dichotomy of health and illness. Drawing from mixed-methods research in Maputo, Mozambique, this paper discusses individuals' use of medicines and other substances - pharmaceuticals, food supplements, traditional herbs, cosmetics and energy drinks - for managing different aspects of their everyday lives. Through an overview of the main consumption practices, we explore the underlying purposes and strategies of users, and the perceived legitimacy and risks involved when using a variety of products accessible through formal and informal exchange channels. From tiredness to sexual and aesthetic management, we show how the body becomes the locus of experimentation and investment to perform in accordance with socially expected roles, individual aspirations and everyday tasks. With insights from individuals' accounts in Maputo, we aim to add to discussions on pharmaceuticalisation of body management by showing how the emergence of new performance consumptions is articulated with the reconfiguration of more 'traditional' consumption practices.

The aerodynamic impact of a range of prostheses designs when cycling with a trans-tibial amputation

Previous studies have proposed that an aerodynamically optimized prosthetic limb could provide performance enhancement for competitive paracyclists. Four different designs of prosthetic limbs were assessed for their impact upon the aerodynamic drag of an elite cyclist with a lower-limb amputation. The pylon area acted as the controlled location for the differences in design between the test prostheses. A validated field test method was used to derive the participant's total aerodynamic drag when using the prostheses designs. The field test method produced a repeatable experimental process and demonstrated that small changes in form made to the pylon region resulted in measurable differences to the participant's cycling performance. In addition, statistical significance was obtained between a baseline design and the prostheses prototype with the greatest aspect ratio (p= <.05). The magnitude of improvements recorded in this study could potentially influence a rider's finishing time at international sporting events like the Paralympic Games.Implications for RehabilitationSmall changes in form made to a cycling prostheses design can potentially deliver worthwhile performance enhancement.Prosthetists may obtain greater end-user satisfaction by taking a broader approach to sports prostheses design than just fit and biomechanical function alone.This study indicates that other regions of the cycling prosthesis could now benefit from aerodynamic optimization with the aim to further improve paracycling performance.

The Potential Role for Cognitive Training in Sport: More Research Needed

Sports performance at the highest level requires a wealth of cognitive functions such as attention, decision making, and working memory to be functioning at optimal levels in stressful and demanding environments. Whilst a substantial research base exists focusing on psychological skills for performance (e.g., imagery) or therapeutic techniques for emotion regulation (e.g., cognitive behavioral therapy), there is a scarcity of research examining whether the enhancement of core cognitive abilities leads to improved performance in sport. Cognitive training is a highly researched method of enhancing cognitive skills through repetitive and targeted exercises. In this article, we outline the potential use of cognitive training (CT) in athlete populations with a view to supporting athletic performance. We propose how such an intervention could be used in the future, drawing on evidence from other fields where this technique is more fruitfully researched, and provide recommendations for both researchers and practitioners working in the field.

The impact of lower-limb prosthetic limb use in international C4 track para-cycling

An investigation was undertaken to ascertain any impact or significance of athletes within the C4 paracycling classification between those who use a lower-limb prostheses and those who do not. A statistical evaluation of event completion time was undertaken to assess C4 cyclists when competing at the World Championships and the Paralympic Games in the 1 km track time trial. The C4 athletes who utilize a prostheses consistently outperformed non-amputees in the C4 classification from 2011 to 2016 on a competition-to-competition basis. However, when the participations were grouped as a whole together and an identified outlier athlete was removed, it was then demonstrated that there was no statistical significance between those who required the use of a lower-limb prostheses to those that did not when either evaluated on a competition-by-competition or on an amputee and non-amputee group-by-group basis (p ≥ 0.05). As a result, this study proposes that those requiring the use of lower-limb prostheses are neither advantaged nor disadvantaged in the C4 classification category when competing in the 1 km time trial at this time. Implications for Rehabilitation This analysis indicates that at this time, there is no evidence to suggest that use of such technology is advantageous in this category or should be seen as controversial. The design of lower-limb prosthetic limb technology in cycling should continue to be developed and optimized unabated. This study begins to address the cited lack of peer-reviewed information regarding paracycling with limb absence available to practitioners.

Safety and performance benefits of arginine supplements for military personnel: a systematic review

CONTEXT

Dietary supplements are widely used by military personnel and civilians for promotion of health.

OBJECTIVE

The objective of this evidence-based review was to examine whether supplementation with l-arginine, in combination with caffeine and/or creatine, is safe and whether it enhances athletic performance or improves recovery from exhaustion for military personnel.

DATA SOURCES

Information from clinical trials and adverse event reports were collected from 17 databases and 5 adverse event report portals.

STUDY SELECTION

Studies and reports were included if they evaluated the safety and the putative outcomes of enhanced performance or improved recovery from exhaustion associated with the intake of arginine alone or in combination with caffeine and/or creatine in healthy adults aged 19 to 50 years.

DATA EXTRACTION

Information related to population, intervention, comparator, and outcomes was abstracted. Of the 2687 articles screened, 62 articles meeting the inclusion criteria were analyzed. Strength of evidence was assessed in terms of risk of bias, consistency, directness, and precision.

RESULTS

Most studies had few participants and suggested risk of bias that could negatively affect the results. l-Arginine supplementation provided little enhancement of athletic performance or improvements in recovery. Short-term supplementation with arginine may result in adverse gastrointestinal and cardiovascular effects. No information about the effects of arginine on the performance of military personnel was available.

CONCLUSIONS

The available information does not support the use of l-arginine, either alone or in combination with caffeine, creatine, or both, to enhance athletic performance or improve recovery from exhaustion. Given the information gaps, an evidence-based review to assess the safety or effectiveness of multi-ingredient dietary supplements was not feasible, and therefore the development of a computational model-based approach to predict the safety of multi-ingredient dietary supplements is recommended.

Application of Mental Skills Training in Surgery: A Review of Its Effectiveness and Proposed Next Steps

INTRODUCTION

Mental skills training, which refers to the teaching of performance enhancement and stress management psychological strategies, may benefit surgeons. Our objective was to review the application of mental skills training in surgery and contrast it to other domains, examine the effectiveness of this approach in enhancing surgical performance and reducing stress, and provide future directions for mental skills training in surgery.

MATERIALS AND METHODS

A systematic literature search of MEDLINE, PubMed, PsycINFO, and ClinicalKey was performed between 1996 and 2016. Keywords included were mental readiness, mental competency, mental skill, mental practice, imagery, mental imagery, mental rehearsal, stress management training, stress coping, mental training, performance enhancement, and surgery. Reviews of mental skills interventions in sport and well-regarded sport psychology textbooks were also reviewed. Primary outcome of interest was the effect of mental skills on surgical performance in the simulated or clinical environment.

RESULTS

Of 490 identified abstracts, 28 articles met inclusion criteria and were reviewed. The majority of the literature provides evidence that mental imagery and stress management training programs are effective at enhancing surgical performance and reducing stress. Studies from other disciplines suggest that comprehensive mental skills programs may be more effective than imagery and stress management techniques alone.

CONCLUSIONS

Given the demonstrated efficacy of mental imagery and stress management training in surgery and the incremental value of comprehensive mental skills curricula used in other domains, a concerted effort should be made to apply comprehensive mental skills curricula during surgical training.

NCAA Football Off-Season Training: Unanswered Prayers… A Prayer Answered

Off-season training in year-round collegiate football is purported to be performance enhancing. Absent principles of exercise physiology, excesses in sport-training regimens pose risk to the participant athletes. Since 2000, 33 National Collegiate Athletic Association (NCAA) football players have died in sport: 27 nontraumatic deaths and 6 traumatic deaths, a ratio of 4.5 nontraumatic deaths for every traumatic death. On average, 2 NCAA football players die per season. Best practices, consensus guidelines, and precautions are ignored, elevating the risk. However, standards exist that will, if heeded, prevent nontraumatic death in athletes training for sport. Sickle cell trait status knowledge and tailored precautions are preventing deaths from exertional collapse associated with sickle cell trait. Adherence to established principles of exercise physiology and best-practice training standards, which is long overdue, will help to prevent not only deaths from exertional collapse associated with sickle cell trait but also sudden cardiac, exertional heat stroke, and asthma deaths.

Biasing neural network dynamics using non-invasive brain stimulation

Recently, non-invasive brain stimulation (NBS) has been discovered as a tool to improve human performance on a wide variety of tasks. Although these observations are highly intriguing, the underlying mechanisms of such enhancements are still poorly understood. Here, we argue that in order to advance our understanding of these mechanisms it is necessary to focus on intrinsic network dynamics in the brain. Taking into account well-known network dynamics, increased excitation in one particular network or brain region may necessarily lead to inhibition of an opposing network (and vice versa). As a consequence, observed behavioral improvements due to NBS may emerge from a shift in the balance between (competing) neural networks in the brain, implicating that behavioral enhancement due to stimulation most likely comes with a cost or side effect. We conclude that more elaborate experimental designs are essential for a better understanding of the relationship between network interactions and the behavioral effects of NBS.

Beyond America's War on Drugs: Developing Public Policy to Navigate the Prevailing Pharmacological Revolution

This paper places America's “war on drugs” in perspective in order to develop a new metaphor for control of drug misuse. A brief and focused history of America's experience with substance use and substance use policy over the past several hundred years provides background and a framework to compare the current Pharmacological Revolution with America's Nineteenth Century Industrial Revolution. The paper concludes with cautions about growing challenges and provides suggestions for navigating this revolution and reducing its negative impact on individuals and society.

Nutritional supplement and doping use in sport: Possible underlying social cognitive processes

There is growing evidence suggesting that nutritional supplement (NS) use is strongly associated to doping use in elite and amateur sports. However, there is a paucity of research on the psychological processes that underlie this association. The present study investigated the cognitive and behavioral components of the association between NS use and doping among adolescent sub-elite athletes. Six hundred and fifty adolescent athletes completed a questionnaire including measures of doping intentions, attitudes, norms, and beliefs about NS use. The results showed that NS users who did not report doping use had significantly stronger doping intentions and more positive attitudes and favorable beliefs toward doping use, as compared with athletes who did not use NS. In support of the "shared mental representations" hypothesis, the present findings show that NS use is associated with biased reasoning patterns in favor of doping use. This mechanism may explain why some NS users decide to engage in doping.

The effects of caffeine, nicotine, ethanol, and tetrahydrocannabinol on exercise performance

Caffeine, nicotine, ethanol and tetrahydrocannabinol (THC) are among the most prevalent and culturally accepted drugs in western society. For example, in Europe and North America up to 90% of the adult population drinks coffee daily and, although less prevalent, the other drugs are also used extensively by the population. Smoked tobacco, excessive alcohol consumption and marijuana (cannabis) smoking are addictive and exhibit adverse health effects. These drugs are not only common in the general population, but have also made their way into elite sports because of their purported performance-altering potential. Only one of the drugs (i.e., caffeine) has enough scientific evidence indicating an ergogenic effect. There is some preliminary evidence for nicotine as an ergogenic aid, but further study is required; cannabis and alcohol can exhibit ergogenic potential under specific circumstances but are in general believed to be ergolytic for sports performance. These drugs are currently (THC, ethanol) or have been (caffeine) on the prohibited list of the World Anti-Doping Agency or are being monitored (nicotine) due to their potential ergogenic or ergolytic effects. The aim of this brief review is to evaluate the effects of caffeine, nicotine, ethanol and THC by: 1) examining evidence supporting the ergogenic or ergolytic effects; 2) providing an overview of the mechanism(s) of action and physiological effects; and 3) where appropriate, reviewing their impact as performance-altering aids used in recreational and elite sports.

A Near-Zero Refractive Index Meta-Surface Structure for Antenna Performance Improvement

A new meta-surface structure (MSS) with a near-zero refractive index (NZRI) is proposed to enhance the performance of a square loop antenna array. The main challenge to improve the antenna performance is increment of the overall antenna volume that is mitigated by assimilating the planar NZRI MSS at the back of the antenna structure. The proposed NZRI MSS-loaded CPW-fed (Co-Planar Waveguide) four-element array antenna is designed on ceramic-bioplastic-ceramic sandwich substrate using high-frequency structure simulator (HFSS), a finite-element-method-based simulation tool. The gain and directivity of the antenna are significantly enhanced by incorporating the NZRI MSS with a 7 × 6 set of elements at the back of the antenna structure. Measurement results show that the maximum gains of the antenna increased from 6.21 dBi to 8.25 dBi, from 6.52 dBi to 9.05 dBi and from 10.54 dBi to 12.15 dBi in the first, second and third bands, respectively. The effect of the slot configuration in the ground plane on the reflection coefficient of the antenna was analyzed and optimized. The overall performance makes the proposed antenna appropriate for UHFFM (Ultra High Frequency Frequency Modulation) telemetry-based space applications as well as mobile satellite, microwave radiometry and radio astronomy applications.

Performance enhancement in the terminal phases of rehabilitation

CONTEXT

There is a dearth of literature on the performance enhancement in the recovering athlete in the terminal phases of rehabilitation. There are established training methods that target strength, power, speed, endurance, and metabolic capacity that all lead to performance enhancement.

EVIDENCE ACQUISITION

A PubMed search from 1980 to 2010 was undertaken for articles in English. Additional references were accrued from reference lists of research articles.

RESULTS

Multiple options are available to improve strength, power, speed, endurance, and metabolic capacity during rehabilitation.

CONCLUSION

Sports clinicians have several components to address in the rehabilitation of a recovering athlete in addition to performance enhancement. Sports clinicians should focus their efforts on increasing power, a product of maximum force and speed of performance.

Emerging supplements in sports

CONTEXT

Nutritional supplements advertised as ergogenic are commonly used by athletes at all levels. Health care professionals have an opportunity and responsibility to counsel athletes concerning the safety and efficacy of supplements on the market.

EVIDENCE ACQUISITION

An Internet search of common fitness and bodybuilding sites was performed to identify supplement promotions. A search of MEDLINE (2000-August, 2011) was performed using the most commonly identified supplements, including glutamine, choline, methoxyisoflavone, quercetin, zinc/magnesium aspartate, and nitric oxide. The search terms supplement, ergogenic aid, and performance were also used.

RESULTS

Six common and newer supplements were identified, including glutamine, choline, methoxyisoflavone, quercetin, zinc/magnesium aspartate, and nitric oxide.

CONCLUSIONS

Controlled studies have not determined the effects of these supplements on performance in athletes. Scientific evidence is not available to support the use of these supplements for performance enhancement.

A nonlinear model for hippocampal cognitive prosthesis: memory facilitation by hippocampal ensemble stimulation

Collaborative investigations have characterized how multineuron hippocampal ensembles encode memory necessary for subsequent successful performance by rodents in a delayed nonmatch to sample (DNMS) task and utilized that information to provide the basis for a memory prosthesis to enhance performance. By employing a unique nonlinear dynamic multi-input/multi-output (MIMO) model, developed and adapted to hippocampal neural ensemble firing patterns derived from simultaneous recorded CA1 and CA3 activity, it was possible to extract information encoded in the sample phase necessary for successful performance in the nonmatch phase of the task. The extension of this MIMO model to online delivery of electrical stimulation delivered to the same recording loci that mimicked successful CA1 firing patterns, provided the means to increase levels of performance on a trial-by-trial basis. Inclusion of several control procedures provides evidence for the specificity of effective MIMO model generated patterns of electrical stimulation. Increased utility of the MIMO model as a prosthesis device was exhibited by the demonstration of cumulative increases in DNMS task performance with repeated MIMO stimulation over many sessions on both stimulation and nonstimulation trials, suggesting overall system modification with continued exposure. Results reported here are compatible with and extend prior demonstrations and further support the candidacy of the MIMO model as an effective cortical prosthesis.

A behavioral intervention for teaching tackling skills to high school football athletes

We evaluated an intervention that combined task analysis and differential reinforcement for teaching tackling skills to 2 high school football athletes. As a result of intervention, both players tackled more proficiently in practice drills and maintained proficient tackling during games.

Dispelling a few false-positives: a reply to MacGregor and McNamee on doping

McGregor and MacNamee recently, in this journal, offered several criticisms of an earlier article in which I attempted to refute a number of arguments for the claim that doping in sports is morally wrong. Their criticisms are numerous, but focus on four domains. First, they sketch a view on which the risk profiles of different sports may make doping permissible in some and impermissible in others. Second, they suggest that my criticisms of safety-based arguments assume that doping opponents are bent on harm elimination, rather than harm management. Finally, they offer two methodological criticisms, the first pertaining to my use of analogical arguments, and the second pertaining to the general difficulties of making revisionist arguments in ethics. I defend my criticisms of safety-based arguments by showing that these do not rest on the assumptions McGregor and MacNamee attribute to me and by noting that their own view about the variable relevance of safety considerations is underdeveloped. As for their methodological arguments, I endeavor to show that these are misplaced, in that they either rest on misinterpretations of my earlier article or on an excessively high standard for ethical argumentation.

Warming-Up Affects Performance and Lactate Distribution between Plasma and Red Blood Cells

Warming-up (WU) is a widely used preparation for training and competition. However, little is known about the potential mechanisms of WU on performance and on the lactate distribution in the blood compartment. The purpose of the present study was to investigate whether different WU procedures affect performance and lactate distribution between plasma and red blood cells (RBCs) after maximal exercise. At three different occasions eleven subjects performed one 30 s maximal effort exercise on a cycle ergometer. Before each exercise, subjects warmed up at different intensities: 1. no WU (NWU); 2. extensive WU (EWU); 3. intensive WU (IWU). Blood samples were taken under resting conditions, after WU, and in 1 minute intervals during recovery to determine lactate concentrations [LA] in whole blood ([LA]WB), plasma ([LA]plasma) and erythrocytes ([LA]RBC). Mean power output was +58 Watt (EWU) and +60 Watt (IWU) higher compared to NWU. For each WU condition [LA]plasma and [LA]RBC differed significantly at any time point, showing greater [LA]plasma compared to [LA]RBC. The maximal effort exercise caused a rapid decrease of the [LA]RBC/[LA]plasma ratio. [LA]RBC reached the peak 3-5 minutes later than [LA]plasma depending on the WU condition. The initial increments in [LA]RBC were 10-16% lower after IWU compared to NWU and EWU. The lower increment of [LA]RBC after IWU might be due to a "higher preloading" with lactate before exercise, causing a smaller initial [LA] gradient between plasma and RBCs. It seems that the influx decreases with increasing intracellular [LA]. Another possibility one could speculate about is, that the extracellular increase in [LA] inhibits the outflux of lactate produced by the RBC itself. This inhibited export of lactate from RBCs may lead to an intracellular lactate accumulation. But the relatively fast increase in [LA]RBC and other investigations partly contradicts this possibility. Key pointsWarm-up significantly improves performance during 30 s maximal effort exercise.No differences in performance were found between extensive and intensive warm-up.Warm-up and maximal effort exercise affects the lactate distribution between plasma and RBC.Lactate influx into RBC decreases with increasing intracellular lactate concentrations.

Doping in sports and its spread to at-risk populations: an international review

Doping is now a global problem that follows international sporting events worldwide. International sports federations, led by the International Olympic Committee, have for the past half century attempted to stop the spread of this problem, with little effect. It was expected that, with educational programs, testing, and supportive medical treatment, this substance-abusing behavior would decrease. Unfortunately, this has not been the case. In fact, new, more powerful and undetectable doping techniques and substances are now abused by professional athletes, while sophisticated networks of distribution have developed. Professional athletes are often the role models of adolescent and young adult populations, who often mimic their behaviors, including the abuse of drugs. This review of doping within international sports is to inform the international psychiatric community and addiction treatment professionals of the historical basis of doping in sport and its spread to vulnerable athletic and non-athletic populations.

Improving strength and postural control in young skiers: whole-body vibration versus equivalent resistance training

CONTEXT

Several groups have undertaken studies to evaluate the physiologic effects of whole-body vibration (WBV). However, the value of WBV in a training program remains unknown.

OBJECTIVE

To investigate whether a WBV program results in a better strength and postural control performance than an equivalent exercise program performed without vibration.

DESIGN

Randomized, controlled trial.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-three Belgian competitive skiers (ages = 9-15 years).

INTERVENTION(S)

Subjects were assigned to either the WBV group or the equivalent resistance (ER) group for 6 weeks of training at 3 times per week.

MAIN OUTCOME MEASURE(S)

Isokinetic plantar and dorsiflexion peak torque, isokinetic knee flexion and extension peak torque, explosive strength (high box test), and postural control were assessed before and after the training period.

RESULTS

Both training programs significantly improved isokinetic ankle and knee muscle strength and explosive strength. Moreover, the increases in explosive strength and in plantar-flexor strength at low speed were significantly higher in the WBV group than in the ER group after 6 weeks. However, neither WBV training nor ER training seemed to have an effect on postural control.

CONCLUSIONS

A strength training program that includes WBV appears to have additive effects in young skiers compared with an equivalent program that does not include WBV. Therefore, our findings support the hypothesis that WBV training may be a beneficial supplementary training technique in strength programs for young athletes.

The use of varying creatine regimens on sprint cycling

This study aimed to determine the effects of different acute creatine loadings (ACRL) on repeated cycle sprints. Twenty-eight active subjects divided into the control (n=7) and the experimental (n=21) group. The exercise protocol comprised three 30s Anaerobic Wingate Tests (AWT) interspersed with six minutes recovery, without any supplements ingested and following placebo and creatine ingestion, according to each ACRL (40g, 100g and 135g throughout a four-day period). Blood and urinary creatine levels were also determined from the experimental group for each ACRL. Protein intake (across all groups) was held constant during the study. There were no changes in protein intake or performance of the control group. For the experimental group creatine supplementation produced significant (p<0.01) increases in body mass (82.5 ± 1.4kg pre vs 82.9 ± 1.2kg post), blood (0.21 ± 0.04mmol·l(-1) pre vs 2.24 ± 0.98mmol·l(-1) post), and urinary creatine (0.23 ± 0.09mmol·l(-1) pre vs 4.29 ± 1.98mmol·l(-1) post). No significant differences were found between the non-supplement and placebo condition. Creatine supplementation produced an average improvement of 0.7%, 11.8% and 11.1% for the 40g, 100g and 135g ACRL respectively. However, statistics revealed significant (p<0.01) differences only for the 100g and 135g ACRL. Mean ± SD values for the 100g ACRL for mean and minimum power were 612 ± 180W placebo vs 693 ± 221W creatine and 381 ± 35W placebo vs 415 ± 11W creatine accordingly. For the 135g ACRL the respective performance values were 722 ± 215W placebo vs 810 ± 240W creatine and 405 ± 59W placebo vs 436 ± 30W creatine. These data indicate that a 100g compared to 40g ACRL produces a greater potentiation of performance whilst, greater quantities of creatine ingestion (135g ACRL) can not provide a greater benefit.

Ephedra and its application to sport performance: another concern for the athletic trainer?

OBJECTIVE

The ma huang herb, otherwise known as ephedra, has gained widespread popularity as an ergogenic supplement. With the sympathomimetic alkaloid ephedrine as its primary active ingredient, ma huang is marketed to reduce fatigue; increase strength, power, and speed; decrease reaction time; and improve body composition. Although numerous side effects have been associated with the use of ma huang, its popularity in athletes continues to grow. This review provides rationale for the ergogenic claims regarding ma huang and compares and contrasts those claims with data from scientifically controlled investigations.

DATA SOURCES

MEDLINE and SPORT Discus were searched from 1970 to 2000 using the key words ma huang, ephedra, and ephedrine in combination with humans, exercise, performance, and side effects.

DATA SYNTHESIS

Ephedrine has been used alone or in combination with other drugs as an effective weight-loss agent. The weight loss has been attributed to thermogenic and lipolytic effects which, in combination with the central nervous system stimulating effects, have also resulted in its use as an ergogenic aid. Most of the scientific data, however, do not support manufacturers' ergogenic claims, and numerous side effects have been associated with ephedrine use. Thus, the safety and efficacy of ma huang as an ergogenic supplement must be questioned.

CONCLUSIONS/RECOMMENDATIONS

It appears that the risks associated with the use of ma huang far outweigh any possible ergogenic benefits. Thus, it is extremely important that athletic trainers educate athletes on these issues so they can continue to perform at an optimum level in a safe and healthy manner.