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The metatarsophalangeal joint is an important contributor to lower limb energetics during sprint running. This study compared the kinematics, kinetics and energetics of the metatarsophalangeal joint during sprinting barefoot and wearing standardized sprint spikes. The aim of this investigation was to determine whether standard sprinting footwear alters the natural motion and function of the metatarsophalangeal joint exhibited during barefoot sprint running. Eight trained sprinters performed maximal sprints along a runway, four sprints in each condition. Three-dimensional high-speed (1000 Hz) kinematic and kinetic data were collected at the 20 m point. Joint angle, angular velocity, moment, power and energy were calculated for the metatarsophalangeal joint. Sprint spikes significantly increase sprinting velocity (0.3 m/s average increase), yet limit the range of motion about the metatarsophalangeal joint (17.9% average reduction) and reduce peak dorsiflexion velocity (25.5% average reduction), thus exhibiting a controlling affect over the natural behavior of the foot. However, sprint spikes improve metatarsophalangeal joint kinetics by significantly increasing the peak metatarsophalangeal joint moment (15% average increase) and total energy generated during the important push-off phase (0.5 J to 1.4 J). The results demonstrate substantial changes in metatarsophalangeal function and potential improvements in performance-related parameters due to footwear.

This study examined attentional processes underlying skilled motor performance in threatening situations. Twenty-four trained participants performed a simulated rally driving task under conditions designed either to direct the focus of attention toward the explicit monitoring of driving or a distracting secondary task. Performance (lap time) was compared with a “driving only” control condition. Each condition was completed under nonevaluative and evaluative instructional sets designed to manipulate anxiety. Mental effort was indexed by self-report and dual-task performance measures. The results showed little change in performance in the high-threat explicit monitoring task condition, compared with either the low-threat or the high-threat distraction conditions. Mental effort increased, however, in all high- as opposed to low-threat conditions. Performance effectiveness was therefore maintained under threat although this was at the expense of reduced processing efficiency. The results provide stronger support for the predictions of processing efficiency theory than self-focus theories of choking.

This paper presents a conceptual model for studying the contribution of each leg to sideways stability of a four-link biped. It was assumed that a linear feedback controller maintained balance with torque related to the deviation from a reference value of the angle made by the trunk with the vertical. Predictions for ground reaction forces produced in resisting sideways push at the pelvis, based on simulation using a simple linear controller, are presented for two special cases (using one or both legs). This simple model was then compared to experimental data in which participants were asked to resist a sideways push. It was observed that all participants employed a strategy in which one leg was used to develop the force response. With this simple model, it was possible to simulate different kinds of responses to the balance perturbation. This model could be considered the first step of a more complex model in order to include specific components related to physiological parameters.

Optimum levels of attentional control are essential to prevent athletes from experiencing performance breakdowns under pressure. The current study explored whether training attentional control using the adaptive dual n-back paradigm, designed to directly target processing efficiency of the main executive functions of working memory (WM), would result in transferrable effects on sports performance outcomes. A total of 30 tennis players were allocated to an adaptive WM training or active control group and underwent 10 days of training. Measures of WM capacity as well as performance and objective gaze indices of attentional control in a tennis volley task were assessed in low- and high-pressure posttraining conditions. Results revealed significant benefits of training on WM capacity, quiet eye offset, and tennis performance in the high-pressure condition. Our results confirm and extend previous findings supporting the transfer of cognitive training benefits to objective measures of sports performance under pressure.

The purpose of this study was to use the Eating Disorders Inventory-2 (EDI-2) to compare disordered eating pathology between female intercollegiate athletes and a control group of nonathletic subjects enrolled in an advanced program of study. Analysis of variance (ANOVA) procedures revealed no significant difference (NSD) (p > .05) between any of the athletic groups or the control group on any EDI-2 subscale, and there was no significant difference between “lean” sports, other sports, and the control group. There was also NSD on EDI-2 subscale scores on the basis of age. African Americans had significantly lower scores on the Body Dissatisfaction and Impulse Regulation subscales than white Americans. Chi-square analysis revealed NSD between any groups in percentage of respondents scoring above anorexic norms. The results did not indicate a greater amount of disordered eating in female athletes compared to nonathlete controls.

Research suggests that physical activity (PA) has many health benefits for an aging population. Evidence exploring the association between PA and vision is limited. This study includes the measures of self-reported PA (International Physical Activity Questionnaire) and self-rated vision at three points in time over a 6-year period used in the Irish Longitudinal study of Ageing, a cohort of community-dwelling older adults (50 years or older). A path analysis found that PA was indirectly associated with vision over 6 years controlling for age, sex, marital status, employment, education, depression (Centre for Epidemiologic Studies Depression Scale), self-reported general health, cardiovascular disease (e.g., heart attack), high blood pressure, diabetes, eye disease (e.g., glaucoma, diabetic eye disease, macular degeneration, cataract), and disabilities associated with activities of daily living. Further research is needed to fully understand the relationship over time and generalize the findings.

The effects of exercise training on hemodynamics and on the prevalence of arrhythmias in 11 asymptomatic children following tetralogy of Fallot (TOF) repair were investigated. Training consisted of three 30-min supervised exercise sessions per week for 8 consecutive weeks. Each subject exercised on a cycle ergometer and/or treadmill at 60–80% of measured peak heart rate (HR). Submaximal HR decreased (p < .0016), and maximal treadmill time increased, in every patient (p < .0004). Small decreases occurred in submaximal cardiac output (CO) (p < .094), VO₂ (p < .047), and respiratory rate (RR) (p < .053). No significant change occurred in peak HR, peak VO₂, or in resting LV end-diastolic dimension or posterior wall thickness. No significant change occurred in atrial or ventricular ectopy. It was concluded that young active children following repair of TOF can demonstrate aerobic training effects with an 8-week exercise program of three 30-minute sessions of moderately intense aerobic activity per week.

Social relationships are central to the health and well-being of older adults. Evidence exploring the association of physical activity (PA) with social isolation and loneliness is limited. This study uses a path analysis to investigate the longitudinal association between loneliness and social isolation with PA using the Irish Longitudinal Study on Ageing. Higher levels of social isolation measured using the Berkman–Syme Social Network Index were directly and indirectly associated with lower levels of walking, moderate PA, and vigorous PA over 6 years. Additionally, higher levels of walking were associated with lower levels of loneliness measured using a modified version of the University of California, Los Angeles loneliness scale over a 3-year period. Future interventions should target individuals who are more socially isolated and explore the effects of different types of PA on loneliness over time.