The aims of this study were to compare drag in swimming children and adults, quantify technique using the technique drag index (TDI), and use the Froude number (Fr) to study whether children or adults reach hull speed at maximal velocity (v max). Active and passive drag was measured by the perturbation method and a velocity decay method, respectively, including 9 children aged 11.7 ± 0.8 and 13 adults aged 21.4 ± 3.7. The children had significantly lower active (k AD) and passive drag factor (k PD) compared with the adults. TDI (k AD/k PD) could not detect any differences in swimming technique between the two groups, owing to the adults swimming maximally at a higher Fr, increasing the wave drag component, and masking the effect of better technique. The children were found not to reach hull speed at v max, and their Fr were 0.37 ± 0.01 vs. the adults 0.42 ± 0.01, indicating adults’ larger wave-making component of resistance at v max compared with children. Fr is proposed as an evaluation tool for competitive swimmers.
Per-Ludvik Kjendlie and Robert Keig Stallman
David P. Johns, Koenraad J. Lindner and Karen Wolko
Two components of Gould’s (1987) model for attrition in youth sport appear to lend themselves to sociological analysis and were adopted as theoretical concepts of social exchange theory (Homans, 1961). The constructs were tested and the role of injury was assessed through a questionnaire completed by 76 former female competitive club gymnasts and through semistructured interviews with 10 of these dropouts. Three major findings resulted, with only partial support for the model. The former gymnasts appeared to have a positive perception of their competence as athletes and indicated that the withdrawal had provided them with the desired time for the pursuit of other leisure activities such as hobbies, being with friends and, for the older dropouts, shopping. Injury, even though it was the second most frequent reason for withdrawal, was not seen as a primary cause. The subsumation of achievement and competence as components of social exchange theory provided a plausible framework for the interpretation of the data which demonstrated that the attraction of alternative status cultures was the strongest factor underlying withdrawal.
Raymond C.Z. Cohen, Paul W. Cleary, Simon M. Harrison, Bruce R. Mason and David L. Pease
The purpose of this study was to determine the pitching effects of buoyancy during all competitive swimming strokes—freestyle, backstroke, butterfly, and breaststroke. Laser body scans of national-level athletes and synchronized multiangle swimming footage were used in a novel markerless motion capture process to produce three-dimensional biomechanical models of the swimming athletes. The deforming surface meshes were then used to calculate swimmer center-of-mass (CoM) positions, center-of-buoyancy (CoB) positions, pitch buoyancy torques, and sagittal plane moments of inertia (MoI) throughout each stroke cycle. In all cases the mean buoyancy torque tended to raise the legs and lower the head; however, during part of the butterfly stroke the instantaneous buoyancy torque had the opposite effect. The swimming strokes that use opposing arm and leg strokes (freestyle and backstroke) had smaller variations in CoM positions, CoB positions, and buoyancy torques. Strokes with synchronized left-right arm and leg movement (butterfly and breaststroke) had larger variations in buoyancy torques, which impacts the swimmer’s ability to maintain a horizontal body pitch for these strokes. The methodology outlined in this paper enables the rotational effects of buoyancy to be better understood by swimmers, allowing better control of streamlined horizontal body positioning during swimming to improve performance.
Dana K. Voelker and Justine J. Reel
figure skating culture that socializes them to desire changing their body weight, shape, size, or appearance to meet performance expectations. In a qualitative interview study, female competitive skaters described immense pressure to meet narrow, often unattainable, and inflexible body ideals. These
Ben-El Berkovich, Alon Eliakim, Dan Nemet, Aliza Hannah Stark and Tali Sinai
Athletes competing in individual sports such as judo are categorized by weight. Before competitions, weight cutting is common. This cross-sectional study was designed to characterize and determine the prevalence of rapid weight loss (RWL) among adolescent judo competitors. Male athletes aged 12- to 17-years old (N = 108) were recruited from local judo teams. Each participant completed a validated questionnaire regarding RWL practices. Anthropometric measurements were also performed. Average age was 14.6 ± 1.6 years and all participants were of normal body mass index (BMI). RWL was practiced by 80% of the athletes before competition, beginning at an average age of 12.5 ± 2.2 years with the highest prevalence (~94%) in the oldest group of judoka (16–17.9 years). Precompetition weight loss duration was 8 ± 5.4 days, with an average weight reduction of 1.5 ± 1.1 kg. The number of weight loss efforts per athlete in the past season was 2.8 ± 2.2. RWL was achieved by increased physical activity (82.6%), skipped meals (56.3%), or fasting at least once (47%). Two-thirds of the athletes indicated that their coaches were the most influential figure in their decision to lose weight before competition. RWL is highly prevalent in adolescent judo competitors. The methods used by these athletes can potentially lead to significant health risks including compromised nutritional status, diminished physical performance and impaired growth and development. It is of great importance to insure that those who guide young adults in weight loss for competitive sports have the knowledge and understanding to make safe recommendations and appropriate decisions regarding achieving specific weight goals.
Relationships between goal related threat appraisal and competitive trait anxiety were examined in a field study with 102 9- to 15-year-old male soccer players. Questionnaires assessed (a) the frequency and intensity of somatic and cognitive symptoms of competitive trait anxiety, (b) the personal importance of various goals in youth sports, (c) children's perceptions of the extent to which these goals were endangered through sport participation, and (d) self-esteem. Correlational analyses indicated significant but weak relationships between a summary appraisal of threat to important goals and the frequency of somatic and cognitive competitive trait anxiety symptoms, and a stronger relationship between summary threat and competitive trait anxiety intensity. Greater perceived threat to effort/mastery and competitive achievement goals was reported by boys with higher, rather than lower, competitive trait anxiety. Within the sample, however, a cluster analysis revealed considerable individual variation in the degree of threat perceived with respect to each of four identified goals.
Diane L. Gill, David A. Dzewaltowski and Thomas E. Deeter
The validity of the recently developed Sport Orientation Questionnaire (SOQ), a multidimensional measure of sport achievement orientation, was investigated with both high school and university students. Specifically, we examined the correlations of SOQ scores with other measures of competitiveness and general achievement orientation and we compared the relative abilities of SOQ scores and other achievement measures to discriminate participants and nonpar-ticipants in competitive sports, noncompetitive sports, and nonsport activities. The findings obtained with both high school and university students provided convergent and divergent evidence for the validity of the SOQ. SOQ scores were highly correlated with other competitiveness measures, moderately correlated with general achievement measures, and uncorrelated with competitive anxiety and social desirability. Competitiveness scores were the strongest discriminators between competitive sport participants and nonpar-ticipants, but SOQ scores were weaker discriminators for noncompetitive achievement choices. The findings confirm the value of a multidimensional, sport-specific achievement measure and provide good evidence for the validity of the Sport Orientation Questionnaire.
Eve Bernstein, Sharon R. Phillips and Stephen Silverman
The attitudes and perceptions of middle school students toward competitive activities in physical education were examined. Ten boys and 14 girls volunteered (11-high-skilled, 11 moderate-skilled, and 2 low skilled students) in 6th and 7th grade from a total of 6 schools, all offering competitive activities. Data collection was conducted over several months and included focus groups consisting of students of mixed skill levels, observations of competitive class activities, and informal interviews with teachers. The three major themes that emerged were, having fun in competitive activities, not all students were attaining motor skills necessary to participate in activities due to a lack of time to engage in appropriate practice, and the structure of competitive activities affects student experience
Anthony Rossi, Tina Claiborne and Jamie Fetter
Aortic valves can be replaced using either mechanical valves or bio-prosthetic implants. Patients who receive mechanical valves are required to be on lifelong anticoagulants necessitating disqualification from competitive sports. 15 Bio-prosthetic valves can degenerate rapidly and require future
Ben T. Stephenson, Sven P. Hoekstra, Keith Tolfrey and Victoria L. Goosey-Tolfrey
severely understudied despite athletes’ commonality in Paralympic sports and similarly increased risk of thermal strain. Competitive events in paratriathlon, the Paralympic variant of triathlon, are commonly held in environments with high ambient temperatures; however, prolonged exercise in hot