Lacrosse Legends of the First Americans

Abstract

The purpose of this study was to examine the distribution of pace self-selected by cyclists of varying ability, biological age and sex performing in a mountain bike World Championship event. Data were collected on cyclists performing in the Elite Male (ELITE_male; n = 75), Elite Female (ELITE_female; n = 50), Under 23 Male (U23_male; n = 62), Under 23 Female (U23_female; n = 34), Junior Male (JNR_male; n = 71) and Junior Female (JNR_female; n = 30) categories of the 2009 UCI Cross-Country Mountain Bike World Championships. Split times were recorded for the top, middle and bottom 20% of all finishers of each category. Timing splits were positioned to separate the course into technical and non-technical, uphill, downhill and rolling/flat sections. Compared with bottom performers, top performers in all male categories (ELITE_male, U23_male, JNR_male) maintained a more even pace over the event as evidenced by a significantly lower standard deviation and range in average lap speed. Top performers, males, and ELITE_male athletes spent a lower percentage of overall race time on technical uphill sections of the course, compared with middle and bottom placed finishers, females, and JNR_male athletes, respectively. Better male performers adopt a more even distribution of pace throughout cross-country mountain events. Performance of lower placed finishers, females and JNR_male athletes may be improved by enhancing technical uphill cycling ability.     

Age,Physical Activity,Physical Fitness,Body Composition,and Incidence of Orthopedic Problems

Abstract

The incidence of orthopedic problems was examined in 5, 582 men and women who attended the Cooper Clinic in Dallas, Texas between 1974 and 1982. The effects of age, physical activity, physical fitness, and body mass index (EMI) on the occurrence of these problems were examined using a proportional hazards approach. The expected risk of orthopedic problems per person-year was 0.045 for men and 0.046 for women. For men, physical fitness, BMI, and physical activity were associated with orthopedic problems, while for women, physical activity was the main predictor. Age was not a factor for either gender. The effect of change in physical fitness, physical activity, and BMI was examined in a subset of 2, 325 persons with more than one visit to the clinic. For women, physical activity and a decrease in BMI were associated with orthopedic problems, while for men none of those factors were significant. Again, age was not a factor in either group. The absence of any age effect on the occurrence of problems suggests that with regard to orthopedic problems, moderate amounts of physical activity in generally healthy persons may be recommended without special consideration as to age.     

Gender and age inequalities in regular sports participation: A cross-national study of 25 European countries

Abstract

This article provides a unique opportunity to compare gender inequalities in sports participation across Europe, and the extent to which this varies by age using large, cross-sections of the population. The Eurobarometer Survey 62.0 (carried out in 2004 at the request of the European Commission and covering the adult population of 25 European member states, N = 23,909) was used to analyse differences in regular sports participation by gender and by age in the different countries. For the majority of countries, the occurrence of regular sporting activity was less than 40%. Additionally, binary logistic regression analyses identified significant gender differences in sports participation in 12 countries. In Belgium, France, Greece, Latvia, Lithuania, Slovakia, Spain, and the UK, men were more likely to report being regularly active in sports than women, whereas in Denmark, Finland, Sweden, and the Netherlands the opposite was true. Moreover, the extent to which these gender inequalities differ by age varies considerably across countries. The results imply that: (i) in some European countries more efforts must be undertaken to promote the original goals of the Sport for All Charter, and (ii) to achieve more female participation in sports will require different policy responses in the diverse European member states.     

Influence of birth quarter on the rate of physical activities and sports participation

Abstract

The purpose of this study was to assess the potential influence of birth quarter on the frequency of physical activity and participation in specific activities during adulthood. We used data from one national and one provincial survey, the 2005 Canadian Community Health Survey and the 1998 Quebec Social and Health Survey (Enquête sociale et de santé du Québec) respectively. We analysed the distribution of participants at each level of practice of a given leisure activity and work-related physical activity. In the Canadian Community Health Survey, a relative age effect was found for participation in soccer in the 25- to 60-year-old population. However, for volleyball, a significant relative age effect was also observed but with over-representation of the last quarters of the year for the whole population and for men aged 12–60 years. In the Quebec Social and Health Survey, significant differences in the frequency of distribution without a relative age effect were revealed for participation in women's ice hockey, work-related physical activity level, and stage of change for physical activity. Overall, the data indicate that the systematic relative age effect reported in other studies for some competitive sports, such as ice hockey and soccer, is not as prevalent in leisure physical activities during adulthood. This may reflect lower competitive selection and attrition in population physical activity compared with competitive sports in younger athletes.     

A behavioural dynamic model of the relative age effect

Abstract

The relationship between date of birth and success in a variety of sports, including hockey, is well established. This phenomenon is known as the relative age effect (RAE). We model the RAE in Canadian youth hockey as a positive feedback loop where an initial age advantage is reinforced through additional training and playing opportunities based on perceived skill superiority. The same causal mechanism leads to a higher quit rate for relatively younger players. Our model effectively replicates the birth month distribution of Canadian National Hockey League players (R² = 86.79%) when driven by Canadian birth distributions. We use this model to evaluate three policies that aim to lessen the RAE. All of the policies reduce the RAE with a significant delay. The most effective policy is a combination of providing additional support to age disadvantaged children and rotating the cut-off date for youth leagues between January 1st and July 1st annually. In equilibrium, this approach leads to a 96% reduction in the RAE compared to the base case.     

Age Differences in use of Strategy for Recall of Movement in a Large Scale Environment

Abstract

In order to investigate how children remember distance (route) and location (landmark) information, two experiments were conducted in a large scale environment using jogging as the means of locomotion. In Experiment 1, thirty 4-year-old and thirty 9-year-old children were randomly assigned within age to three groups which were cued prior to the jog to remember the event, location of the event or distance to the event. Results indicated that older children reproduced the location and distance better than younger children. Cueing children to remember the location resulted in more accurate estimates than the other conditions. In Experiment 2, 5-year-old, 9-year-old, and 12-year-old children (24 children of each age) were randomly divided into step counting strategy and control groups, and asked to reproduce a criterion distance jogged. Results indicated that the three strategy groups and the 12-year-old controls estimated distance with similar accuracy, but the 9- and 5-year-old controls were different, as their error was inversely related to age.     

Age and Sex Differences in Motor Performance of 3 through 6 Year Old Children

Abstract

This study examined the relationship of age and sex to the performance of 3, 4, 5, and 6 year olds on seven motor performance test items. Although significant age and sex differences were found on most of the motor tests, it appears that age generally was related more to performance than was gender. Overall, change with age was fairly linear except perhaps for balancing and a general tapering in improvement in the 5 to 6 year old category. On the tests of throwing and balancing, gender was as important as age, or more so, in its relationship to performance. Boys were superior to girls at all ages on the throwing tests; girls were superior to boys at age 6 on the Balance test. Gender differences of a lesser magnitude were found on the Speed Run and Standing Long Jump tests with the performance of boys generally being superior to the performance of girls. Thus, it appears that gender differences in motor performance occur as early as the preschool years. Interestingly, except for the Balance test, on all the tests the 3 and 4 year old boys performed similarly and the 5 and 6 year old boys performed similarly. For the girls there were more significant differences from year to year in performance, with the data generally indicating at least three distinct skill groups for girls from age 3 to 6.     

The Effects of Age and Number of Demonstrations on Modeling of Form and Performance

Abstract

This study was designed to investigate the effects of age and number of demonstrations on both form (strategy employed) and physical performance on a Bachman ladder-balance task. College age (n = 60) and elementary age females (n = 60) were compared under four modeling conditions consisting of no, four, eight, and 12 demonstrations in an Age Group × Demonstration Group (2 × 4) MANOVA. Results indicated that college age students had higher performance and form scores than elementary age students. Only form differentiated the four demonstration groups. Participants receiving 12 demonstrations had higher form scores than the control participants. Form scores were analyzed in a discriminant function analysis to determine which of five form components differentiated the four demonstration groups. Results also revealed that climbing quickly was the component of form that differentiated the groups the most. It was concluded that matching form by the learner may be a more effective measure of modeling effects rather than inferring modeling from performance, especially in the initial stages of learning. In addition, it appears that the number of demonstrations needed to create modeling effects is task specific and dependent on the length of the practice period.     

Web-Based Learning and Teaching Technologies: Opportunities and Challenges,edited by A. Aggarwal. Hershey,PA: Idea Group Publishing, 2000. vi + 372 pp. $69.95. ISBN 1-878-28960-8

We examined the nature and content of 150 randomly selected pornographic images available in Usenet newsgroups on the Internet in April 1994. Using content analysis, we identified themes that appear most frequently and explored differences in the type of material posted by commercial and noncommercial users. Results suggest that commercial vendors are more likely to post explicit pornographic material in public access newsgroups to attract new customers to their private, pay-per-use bulletin board services.     

Weaving a New 'Net: A Mesh-Based Solution for Democratizing Networked Communications

Although the Internet is largely decentralized in its communication and social patterns, its technical and regulatory apparatuses are highly centralized and hierarchical. Consequently, digital communications are vulnerable to a degree of surveillance and censorship that would be unthinkable in traditional social arenas, threatening “Internet freedom” and cyberliberties in both democratic and politically repressed societies. We believe a new architecture is required in order to protect the continuance of civil liberties in networked society. In this article, we propose 10 “social specifications” describing the requirements of such a network, and outline an architecture called MondoNet that meets these specifications using ad hoc, wireless mesh networking technologies. We also address the legal and technical challenges facing the MondoNet project, and anticipate future developments in this field.