Nutrition for power sports: middle-distance running, track cycling, rowing, canoeing/kayaking, and swimming

Contemporary training for power sports involves diverse routines that place a wide array of physiological demands on the athlete. This requires a multi-faceted nutritional strategy to support both general training needs--tailored to specific training phases--as well as the acute demands of competition. Elite power sport athletes have high training intensities and volumes for most of the training season, so energy intake must be sufficient to support recovery and adaptation. Low pre-exercise muscle glycogen reduces high-intensity performance, so daily carbohydrate intake must be emphasized throughout training and competition phases. There is strong evidence to suggest that the timing, type, and amount of protein intake influence post-exercise recovery and adaptation. Most power sports feature demanding competition schedules, which require aggressive nutritional recovery strategies to optimize muscle glycogen resynthesis. Various power sports have different optimum body compositions and body weight requirements, but increasing the power-to-weight ratio during the championship season can lead to significant performance benefits for most athletes. Both intra- and extracellular buffering agents may enhance performance, but more research is needed to examine the potential long-term impact of buffering agents on training adaptation. Interactions between training, desired physiological adaptations, competition, and nutrition require an individual approach and should be continuously adjusted and adapted.     

Psychosocial correlates of bulimic symptoms among NCAA division-I female collegiate gymnasts and swimmers/divers

In this study, we tested Petrie and Greenleaf's (2007) model of bulimic symptoms in two independent samples of female collegiate swimmers/divers and gymnasts. Structural equation modeling revealed support for the model, although it also suggested additional pathways. Specifically, general societal pressures regarding weight and body were related to the internalization of those ideals and, subsequently, to increases in body dissatisfaction. Pressures from the sport environment regarding weight and appearance were associated with more body dissatisfaction and more restrictive eating. Body dissatisfaction was related to more feelings of sadness, anger, and fear among the athletes. Negative affect, body dissatisfaction, and dietary restraint were related directly to bulimic symptoms, accounting for 55-58% of its variance. These results suggest that general sociocultural pressures are influential, but weight and appearance pressures in the sport environment may be even more pervasive and negative for female athletes.     

A variable drag coefficient,spatially extended numerical model of hammer throws and new wind tunnel data on current hammers

The maximum distance a hammer can be thrown depends on its mass, length and aerodynamic drag, meaning that record hammer throws performed before and after a rule change (for example, if the minimum mass is changed) cannot be compared directly. However, if all factors affecting the flight of a hammer are fully understood, and the range travelled by a hammer thrown with a given initial speed, angle and release height can be predicted, records thrown under different rules can be compared. In this work, a numerical model is developed, which includes the effects of atmospheric pressure, altitude, Coriolis Effect, gravitational variation, wind speed, ambient temperature, linear drag, torsional drag, hammer size and hammer orientation. It is based on the model of Mizera and Horvath (J Biomech 35:785–796, 2002). Two refinements are made: the drag coefficient varies with Reynolds number, and the hammer is represented as a spatially extended object with nonzero moment of inertia. New wind tunnel data on the drag of the three main components of the hammer (ball, cable and handle) are presented. This data are incorporated into the model which is then used to predict throws made at the IAAF 2011 World Athletics Championships (Daegu, Korea). The model is shown to be capable of predicting to within 1 % the distance of hammer throws where the air density, latitude, release height, release angle and release velocity are known. It is more accurate than numeric and analytic models which assume a constant drag coefficient. This may be because it does not require the user to choose the drag coefficient and automatically uses an appropriate drag coefficient regardless of conditions. With a good biomechanical model or good assumptions about release speeds, throws with different implements can be compared to compare records thrown before and after rule changes. Further work is needed to develop a biomechanical model capable of predicting the release speed an athlete can achieve with a range of different implements.     

Decentering the teacher: a practitioner's acccount

This article is an account of an action research project conducted in a first grade classroom. The practitioner-researcher describes a process of “decentering.” Realizing that centering learners necessarily means decentering the practitioner, the author collaborates with his first grade class to identify and clarify the problems associated with teacher centeredness. This article describes the groups' development and implementation of strategies and includes reflections upon understandings and project-derived assertions. The account presents students' perspectives and interpretations and the practitioner's emergent theories as they evolved throughout this collaborative endeavor. The author asserts that the research has potential relevancy to a variety of other teaching contexts.     

More Film Books

Paul Trent and Richard Lawton's The Image Makers: Sixty Years of Hollywood Glamour (New York: McGraw-Hill, 1972—$20.00, but $16.95 before January 1, 1977)

Laurence Kardish's Reel Plastic Magic: A History of Films and Filmmaking in America (Boston: Little, Brown, 1972—$7.50)

David Manning White and Richard Averson's The Celluloid Weapon: Social Comment in the American Film (Boston: Beacon Press, 1972—$14.95)

Edward Mapp's Blacks in American Films: Today and Yesterday (Metuchen, N.J.: Scarecrow Press, 1972—$7.50)

Charles Higham's Hollywood at Sunset (New York: Saturday Review Press, 1972—$6.95)

Jean Narbonl and Tom Milne (eds), Godard on Godard: Critical Writings by Jean-Luc Godard (New York: Viking Press, 1972—$10.00)

Kenneth H. Roberts and Win Sharples, Jr. A Primer for Film-Making: A Complete Guide to 16 and 35 mm. Film Prodution (New York: Pegasus/Bobbs-Merrill, $15.00/6.95)

Stephen Farber's The Movie Rating Game (Washington, D.C.: Public Affairs Press, 1972—$4.50)     

An Examination of Psychosocial Correlates of Eating Disorders Among Female Collegiate Athletes

With female collegiate athletes, we examined the relationship of eating pathology to body image concerns, weight pressures, sociocultural internalization, and mood state. Multivariate analyses revealed that the symptomatic and eating disorder groups were similar on seven of eight weight pressures, three of four mood states, on internalization, and on five of six body image measures; in all instances, these two groups reported more pathological scores than the asymptomatic athletes. Except for pressures from coaches, the psychosocial variables differentiated the groups, correctly classifying 79% of the cases. These findings suggest that athletes symptomatic of eating disorders report similarly high levels of disturbance across a wide range of psychosocial risk factors, and both groups warrant prevention and treatment efforts.