The impact of 100 hours of exercise and sleep deprivation on cognitive function and physical capacities

Abstract

In this study, we examined the effect of 96–125 h of competitive exercise on cognitive and physical performance. Cognitive performance was assessed using the Stroop test (n = 9) before, during, and after the 2003 Southern Traverse adventure race. Strength (MVC) and strength endurance (time to failure at 70% current MVC) of the knee extensor and elbow flexor muscles were assessed before and after racing. Changes in vertical jump (n = 24) and 30-s Wingate performance (n = 27) were assessed in a different group of athletes. Complex response times were affected by the race (16% slower), although not significantly so (P = 0.18), and were dependent on exercise intensity (less so at 50% peak power output after racing). Reduction of strength (P < 0.05) of the legs (17%) and arms (11%) was equivalent (P = 0.17). Reductions in strength endurance were inconsistent (legs 18%, P = 0.09; arms 13%, P = 0.40), but were equivalent between limbs (P = 0.80). Similar reductions were observed in jump height (?8 ± 9%, P < 0.01) and Wingate peak power (?7 ± 15%, P = 0.04), mean power (?7 ± 11%, P < 0.01), and end power (?10 ± 11%, P < 0.01). We concluded that: moderate-intensity exercise may help complex decision making during sustained stress; functional performance was modestly impacted, and the upper and lower limbs were affected similarly despite being used disproportionately.     

Effects of a feint on reactive agility performance

Abstract

This study compared reactive agility between higher-standard (n = 14) and lower-standard (n = 14) Australian footballers using a reactive agility test incorporating a life-size video image of another player changing direction, including and excluding a feint. Mean agility time in the feint trials was 34% (509 ± 243 ms; p < 0.001; effect size 3.06) longer than non-feint trials. In higher-standard players, agility time was shorter than for lower-standard players in both feint (114 ± 140 ms; p = 0.18; effect size 0.52; likely beneficial) and non-feint (32 ± 44 ms; p = 0.22; effect size 0.47; possibly beneficial) trials. Additionally, the inclusion of a feint resulted in movement time increasing over three times more in the lower-standard group (197 ± 91 ms; p = 0.001; effect size 1.07; almost certainly detrimental) than the higher-standard group (62 ± 86 ms; p = 0.23; effect size 0.66; likely detrimental). There were weak correlations between the feint and non-feint trials (r = ?0.13–0.14; p > 0.05), suggesting that reactive agility involving a feint is a unique skill. Also, higher-standard players are more agile than their lower-standard peers, whose movement speed deteriorates more as task complexity increases with the inclusion of a feint. These results support the need for specific training in multi-turn reactive agility tasks.     

UNDOING GENDER THROUGH LEGISLATION AND SCHOOLING: THE CASE OF AB 537 AND AB 394 IN CALIFORNIA, USA

This article investigates California laws AB 537: The Student Safety and Violence Prevention Act of 2000, and the recently enacted AB 394: Safe Place to Learn Act. Both demand that gender identity and sexual orientation be added to the lexicon of anti-harassment protection in public education. However, despite these progressive measures, schools have an unconscious acceptance of heteronormativity and gendered norms, which undermines both the spirit and language of these laws. This paper examines how California schools can both change standard practices and realise the transformative social change that laws like AB 537 and AB 394 can instigate. I assert that the systemic implementation of these laws, through the adoption, enforcement and evaluation of existing AB 537 Task Force Recommendations, is necessary for their success. My second assertion is that AB 537 and AB 394 have the potential to change and reconstitute gender-based and heteronormative standards at school sites.     

Improving CFD prediction of drag on Paralympic tandem athletes: influence of grid resolution and turbulence model

Tandem cycling enables visually impaired athletes to compete in cycling in the Paralympics. Tandem aerodynamics can be analysed by track measurements, wind-tunnel experiments and numerical simulations with computational fluid dynamics (CFD). However, the proximity of the pilot (front) and the stoker (rear) and the associated strong aerodynamic interactions between both athletes present substantial challenges for CFD simulations, the results of which can be very sensitive to computational parameters such as grid topology and turbulence model. To the best of our knowledge, this paper presents the first CFD and wind-tunnel investigation on tandem cycling aerodynamics. The study analyses the influence of the CFD grid topology and the turbulence model on the aerodynamic forces on pilot and stoker and compares the results with wind-tunnel measurements. It is shown that certain combinations of grid topology and turbulence model give trends that are opposite to those shown by other combinations. Indeed, some combinations provide counter-intuitive drag outcomes with the stoker experiencing a drag force up to 28% greater than the pilot. Furthermore, the application of a blockage correction for two athlete bodies in close proximity is investigated. Based on a large number of CFD simulations and validation with wind-tunnel measurements, this paper provides guidelines for the accurate CFD simulation of tandem aerodynamics.     

Hurricane Sandy Exposure Alters the Development of Neural Reactivity to Negative Stimuli in Children

This study examined whether exposure to Hurricane Sandy‐related stressors altered children's brain response to emotional information. An average of 8 months (M_age = 9.19) before and 9 months after (M_age = 10.95) Hurricane Sandy, 77 children experiencing high (n = 37) and low (n = 40) levels of hurricane‐related stress exposure completed a task in which the late positive potential, a neural index of emotional reactivity, was measured in response to pleasant and unpleasant, compared to neutral, images. From pre‐ to post‐Hurricane Sandy, children with high stress exposure failed to show the same decrease in emotional reactivity to unpleasant versus neutral stimuli as those with low stress exposure. Results provide compelling evidence that exposure to natural disaster‐related stressors alters neural emotional reactivity to negatively valenced information.     

Developing Study Guides for Middle School Learners

Study guides are a popular tool teachers provide to help students prepare for an upcoming test or quiz. They are especially appropriate for middle school students as they transition from reading narrative to informational text. However, some teachers are unfamiliar with various types of study guides. Therefore, this article describes various types of study guides middle school teachers can develop to support student learning.     

Delayed Disaster Impacts on Academic Performance of Primary School Children

Social disruption caused by natural disasters often interrupts educational opportunities for children. However, little is known about children's learning in the following years. This study examined change in academic scores for children variably exposed to a major bushfire in Australia. Comparisons were made between children attending high, medium, and low disaster-affected primary schools 2–4 years after the disaster (n = 24,642; 9–12 years). The results showed that in reading and numeracy expected gains from Year 3 to Year 5 scores were reduced in schools with higher levels of bushfire impact. The findings highlight the extended period of academic impact and identify important opportunities for intervention in the education system to enable children to achieve their academic potential.