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Australian Institute of Sport

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Scattone Silva R.,Australian Institute of Sport
Medicine and Science in Sports and Exercise | Year: 2017

PURPOSE: To verify the immediate effects of altering sagittal plane trunk position during jump-landings on lower limb biomechanics, patellar tendon force and pain of athletes with and without patellar tendinopathy. METHODS: Twenty-one elite male athletes were categorized into 3 groups, athletes with patellar tendinopathy (TG, n=7), asymptomatic athletes with patellar tendon abnormalities (AG, n=7) and asymptomatic athletes without tendon abnormalities (CG, n=7). A biomechanical evaluation was conducted while the athletes performed drop landings from a bench in a self-selected trunk position (SS). Afterwards, the athletes were randomly assigned to land with either a flexed trunk position (FLX) or an extended trunk position (EXT). Variables of interest for this study included sagittal plane peak kinematics, kinetics, patellar tendon force and pain during the landing tasks. RESULTS: Peak patellar tendon force, knee extensor moment and knee pain decreased in the FLX landing compared to the SS landing, regardless of group. In addition, peak patellar tendon force, knee extensor moment and vertical ground reaction force were smaller in the FLX landing compared to the EXT landing. The TG had smaller peak ankle dorsiflexion than the CG during jump-landings, regardless of trunk position. CONCLUSION: Landing with greater trunk flexion decreased patellar tendon force in elite jumping athletes. An immediate decrease in knee pain was also observed in symptomatic athletes with a more flexed trunk position during landing. Increasing trunk flexion during landing might be an important strategy to reduce tendon overload in jumping athletes. © 2017 American College of Sports Medicine


Cook J.L.,Monash University | Purdam C.R.,Australian Institute of Sport
British Journal of Sports Medicine | Year: 2014

Managing tendinopathy in season is a challenge for all sports medicine practitioners. Many of the strategies employed to treat tendinopathy in a rehabilitation setting are not suitable because of the time taken to recover. Management strategies that control pain and maintain performance are required. These include load management, both reducing aggravating loads and introducing pain-relieving loads, medications and adequate monitoring to detect a deteriorating tendon. Other interventions such as intratendinous injection therapies and other direct tendon modalities can be provocative at worst and without effect at best. Research to improve the understanding of management in athletes in season is compromised by ethical considerations and access to willing participants. It is likely to remain an area where clinical advances guide future treatments.


Cook J.L.,Monash University | Purdam C.,Australian Institute of Sport
British Journal of Sports Medicine | Year: 2012

Tendons are designed to take tensile load, but excessive load can cause overuse tendinopathy. Overuse tendinopathy Results: in extensive changes to the cells and extracellular matrix, resulting in activated cells, increase in large proteoglycans and a breakdown of the collagen structure. Within these pathological changes, there are areas of fibrocartilaginous metaplasia, and mechanotransduction models suggest that this response could be due to compressive load. As load management is a cornerstone of treating overuse tendinopathy, defining the effect of tensile and compressive loads is important in optimising the clinical management of tendinopathy. This paper examines the potential role of compressive loads in the onset and perpetuation of tendinopathy, and reviews the anatomical, epidemiological and clinical evidence that supports consideration of compressive loads in overuse tendinopathy.


Halson S.L.,Australian Institute of Sport
Sports Medicine | Year: 2014

Sleep has numerous important physiological and cognitive functions that may be particularly important to elite athletes. Recent evidence, as well as anecdotal information, suggests that athletes may experience a reduced quality and/or quantity of sleep. Sleep deprivation can have significant effects on athletic performance, especially submaximal, prolonged exercise. Compromised sleep may also influence learning, memory, cognition, pain perception, immunity and inflammation. Furthermore, changes in glucose metabolism and neuroendocrine function as a result of chronic, partial sleep deprivation may result in alterations in carbohydrate metabolism, appetite, food intake and protein synthesis. These factors can ultimately have a negative influence on an athlete's nutritional, metabolic and endocrine status and hence potentially reduce athletic performance. Research has identified a number of neurotransmitters associated with the sleep-wake cycle. These include serotonin, gamma-aminobutyric acid, orexin, melanin-concentrating hormone, cholinergic, galanin, noradrenaline, and histamine. Therefore, nutritional interventions that may act on these neurotransmitters in the brain may also influence sleep. Carbohydrate, tryptophan, valerian, melatonin and other nutritional interventions have been investigated as possible sleep inducers and represent promising potential interventions. In this review, the factors influencing sleep quality and quantity in athletic populations are examined and the potential impact of nutritional interventions is considered. While there is some research investigating the effects of nutritional interventions on sleep, future research may highlight the importance of nutritional and dietary interventions to enhance sleep. © The Author(s) 2014.


Recovery after strenuous exercise involves processes that are dependent on fl uid and food intake. Current sports nutrition guidelines provide recommendations for the quantity and timing of consumption of nutrients to optimise recovery issues such as refuelling, rehydration and protein synthesis for repair and adaptation. Recovery of immune and antioxidant systems is important but less well documented. In some cases, there is little effective recovery until nutrients are supplied, while in others, the stimulus for recovery is strongest in the period immediately after exercise. Lack of appropriate nutritional support will reduce adaption to exercise and impair preparation for future bouts. Ramadan represents a special case of intermittent fasting undertaken by many athletes during periods of training as well as important competitive events. The avoidance of fl uid and food intake from sunrise to sundown involves prolonged periods without intake of nutrients, infl exibility with the timing of eating and drinking over the day and around an exercise session, and changes to usual dietary choices due to the special foods involved with various rituals. These outcomes will all challenge the athlete's ability to recover optimally between exercise sessions undertaken during the fast or from day to day.


Burke L.M.,Australian Institute of Sport
Scandinavian Journal of Medicine and Science in Sports | Year: 2010

Availability of carbohydrate as a substrate for the muscle and central nervous system is critical for the performance of both intermittent high-intensity work and prolonged aerobic exercise. Therefore, strategies that promote carbohydrate availability, such as ingesting carbohydrate before, during and after exercise, are critical for the performance of many sports and a key component of current sports nutrition guidelines. Guidelines for daily carbohydrate intakes have evolved from the " one size fits all" recommendation for a high-carbohydrate diets to an individualized approach to fuel needs based on the athlete's body size and exercise program. More recently, it has been suggested that athletes should train with low carbohydrate stores but restore fuel availability for competition (" train low, compete high"), based on observations that the intracellular signaling pathways underpinning adaptations to training are enhanced when exercise is undertaken with low glycogen stores. The present literature is limited to studies of " twice a day" training (low glycogen for the second session) or withholding carbohydrate intake during training sessions. Despite increasing the muscle adaptive response and reducing the reliance on carbohydrate utilization during exercise, there is no clear evidence that these strategies enhance exercise performance. Further studies on dietary periodization strategies, especially those mimicking real-life athletic practices, are needed. © 2010 John Wiley & Sons A/S.


Halson S.L.,Australian Institute of Sport
International Journal of Sports Physiology and Performance | Year: 2011

An increase in research investigating recovery strategies has occurred alongside the increase in usage of recovery by elite athletes. Because there is inconsistent evidence regarding the benefits of recovery on performance, it is necessary to examine research design to identify possible strategies that enhance performance in different athlete settings. The purpose of this review is to examine available recovery literature specifically related to the time frame between performance assessments to identify considerations for both research design and practical use of recovery techniques. © 2011 Human Kinetics Inc.


Garth A.K.,Australian Institute of Sport | Burke L.M.,Australian Institute of Sport
Sports Medicine | Year: 2013

Although expert groups have developed guidelines for fluid intake during sports, there is debate about their real-world application. We reviewed the literature on self-selected hydration strategies during sporting competitions to determine what is apparently practical and valued by athletes. We found few studies of drinking practices involving elite or highly competitive athletes, even in popular sports. The available literature revealed wide variability in fluid intake and sweat losses across and within different events with varied strategies to allow fluid intake. Typical drinking practices appear to limit body mass (BM) losses to ~2 % in non-elite competitors. There are events, however, in which mean losses are greater, particularly among elite competitors and in hot weather, and evidence that individual participants fail to meet current guidelines by gaining BM or losing >2 % BM over the competition activity. Substantial (>5 %) BM loss is noted in the few studies of elite competitors in endurance and ultra-endurance events; while this may be consistent with winning outcomes, such observations cannot judge whether performance was optimal for that individual. A complex array of factors influence opportunities to drink during continuous competitive activities, many of which are outside the athlete's control: these include event rules and tactics, regulated availability of fluid, need to maintain optimal technique or speed, and gastrointestinal comfort. Therefore, it is questionable, particularly for top competitors, whether drinking can be truly ad libitum (defined as "whenever and in whatever volumes chosen by the athlete"). While there are variable relationships between fluid intake, fluid balance across races, and finishing times, in many situations it appears that top athletes take calculated risks in emphasizing the costs of drinking against the benefits. However, some non-elite competitors may need to be mindful of the disadvantages of drinking beyond requirements during long events. Across the sparse literature on competition hydration practices in other sports, there are examples of planned and/or ad hoc opportunities to consume fluid, where enhanced access to drinks may allow situations at least close to ad libitum drinking. However, this situation is not universal and, again, the complex array of factors that influence the opportunity to drink during an event is also often beyond the athletes' control. Additionally, some competition formats result in athletes commencing the event with a body fluid deficit because of their failure to rehydrate from a previous bout of training/competition or weight-making strategies. Finally, since fluids consumed during exercise may also be a source of other ingredients (e.g., carbohydrate, electrolytes, or caffeine) or characteristics (e.g., temperature) that can increase palatability or performance, there may be both desirable volumes and patterns of intake that are independent of hydration concerns or thirst, as well as benefits from undertaking a "paced" fluid plan. Further studies of real-life hydration practices in sports including information on motives for drinking or not, along with intervention studies that simulate the actual nature of real-life sport, are needed before conclusions can be made about ideal drinking strategies for sports. Different interpretations may be needed for elite competitors and recreational participants. © 2013 Springer International Publishing Switzerland.


Welsh A.H.,Australian National University | Knight E.J.,Australian Institute of Sport
Medicine and Science in Sports and Exercise | Year: 2014

Purpose: We consider "magnitude-based inference" and its interpretation by examining in detail its use in the problem of comparing two means. Methods: We extract from the spreadsheets, which are provided to users of the analysis (http:// www.sportsci.org/), a precise description of how "magnitude-based inference" is implemented.We compare the implemented version of the method with general descriptions of it and interpret the method in familiar statistical terms. Results and Conclusions: We show that "magnitude-based inference" is not a progressive improvement on modern statistics. The additional probabilities introduced are not directly related to the confidence interval but, rather, are interpretable either as P values for two different nonstandard tests (for different null hypotheses) or as approximate Bayesian calculations, which also lead to a type of test. We also discuss sample size calculations associated with "magnitude-based inference" and show that the substantial reduction in sample sizes claimed for the method (30% of the sample size obtained from standard frequentist calculations) is not justifiable so the sample size calculations should not be used. Rather than using "magnitude-based inference," a better solution is to be realistic about the limitations of the data and use either confidence intervals or a fully Bayesian analysis. © 2014 by the American College of Sports Medicine.


Halson S.L.,Australian Institute of Sport
Sports Medicine | Year: 2014

Many athletes, coaches, and support staff are taking an increasingly scientific approach to both designing and monitoring training programs. Appropriate load monitoring can aid in determining whether an athlete is adapting to a training program and in minimizing the risk of developing non-functional overreaching, illness, and/or injury. In order to gain an understanding of the training load and its effect on the athlete, a number of potential markers are available for use. However, very few of these markers have strong scientific evidence supporting their use, and there is yet to be a single, definitive marker described in the literature. Research has investigated a number of external load quantifying and monitoring tools, such as power output measuring devices, time-motion analysis, as well as internal load unit measures, including perception of effort, heart rate, blood lactate, and training impulse. Dissociation between external and internal load units may reveal the state of fatigue of an athlete. Other monitoring tools used by high-performance programs include heart rate recovery, neuromuscular function, biochemical/hormonal/immunological assessments, questionnaires and diaries, psychomotor speed, and sleep quality and quantity. The monitoring approach taken with athletes may depend on whether the athlete is engaging in individual or team sport activity; however, the importance of individualization of load monitoring cannot be over emphasized. Detecting meaningful changes with scientific and statistical approaches can provide confidence and certainty when implementing change. Appropriate monitoring of training load can provide important information to athletes and coaches; however, monitoring systems should be intuitive, provide efficient data analysis and interpretation, and enable efficient reporting of simple, yet scientifically valid, feedback. © 2014, The Author(s).

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