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It is well known that skilled batters in fast-ball sports do not align their gaze with the ball throughout ball-flight, but instead adopt a unique sequence of eye and head movements that contribute toward their skill. However, much of what we know about visual-motor behavior in hitting is based on studies that have employed case study designs, and/or used simplified tasks that fall short of replicating the spatiotemporal demands experienced in the natural environment. The aim of this study was to provide a comprehensive examination of the eye and head movement strategies that underpin the development of visual-motor expertise when intercepting a fast-moving target. Eye and head movements were examined in situ for 4 groups of cricket batters, who were crossed for playing level (elite or club) and age (U19 or adult), when hitting balls that followed either straight or curving ('swinging') trajectories. The results provide support for some widely cited markers of expertise in batting, while questioning the legitimacy of others. Swinging trajectories alter the visual-motor behavior of all batters, though in large part because of the uncertainty generated by the possibility of a variation in trajectory rather than any actual change in trajectory per se. Moreover, curving trajectories influence visual-motor behavior in a nonlinear fashion, with targets that curve away from the observer influencing behavior more than those that curve inward. The findings provide a more comprehensive understanding of the development of visual-motor expertise in interception. (PsycINFO Database Record

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The focus of this review is to evaluate the influence of b 2 -adrenergic receptor (ADRB2) polymorphism on human physiological function and in turn on athletic performance. A narrative review is conducted on available literature using MedLine, Pubmed and the Cochrane Library to document the location and function of ADRB2 receptors, and specifically to address the influence of genetic polymorphisms on cardiovascular, respiratory, metabolic and musculoskeletal systems and athletic performance. Search terms included ADRB2, endurance and polymorphism. Previous literature exploring the genetic composition of athletes has proposed that alterations in the genetic structure result in an enhancement in their capacity to achieve successful aerobic phenotypes such as a higher VO 2max and increased fat oxidation. Polymorphism of the Gly16Glu27 haplotype is believed to promote positive aerobic phenotypes and regulate optimal lipolysis. Greater knowledge of the ADRB2 polymorphism can aid in understanding the specific phenotypes that are altered, which may influence performance. Until the interaction between fatigue and athletic performance is better understood, the development of appropriate training principles to enhance genetically polymorphic aerobic phenotypes remains complicated. Following the review, there is still no distinctive evidence for the predictive ability of the polymorphism of ADRB2 genotype for the purpose of identifying potential elite athletes.