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Donal Murray, Kevin C. Miller and Jeffrey E. Edwards

Clinical Scenario:

Although exercise-associated muscle cramps (EAMC) are common in ultradistance runners and athletes in general, their etiology remains unclear. EAMC are painful, sudden, involuntary contractions of skeletal muscle occurring during or after exercise and are recognized by visible bulging or knotting of the whole, or part of, a muscle. Many clinicians believe EAMC occur after an imbalance in electrolyte concentrations, specifically serum sodium concentration ([Na+]s) and serum potassium concentration ([K+]s). Studies that have established a link between EAMC occurrence and serum electrolyte concentrations after an athletic event are unhelpful.

Focused Clinical Question:

Are [Na+]s and [K+]s different in athletes who experience EAMC than noncrampers?

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Margaret Carlisle Duncan and Cynthia A. Hasbrook

Televised texts of women’s sports are examined using the hermeneutical method. This study begins with the observation that women’s participation in team sports and certain “male-appropriate” individual sports is significantly lower than men’s participation in these sports. More striking yet is the media’s (particularly television’s) virtual disregard of women in team sports and certain individual sports. On the basis of these observations, the authors frame their research question: Do these imbalances constitute a symbolic denial of power for women? To answer this question, the authors investigate televised depictions of basketball, surfing, and marathon running. In each sport, the television narratives and visuals of the women’s competition are contrasted with those of the men’s competition. These depictions reveal a profound ambivalence in the reporting of the women’s sports, something that is not present in the reporting of the men’s sports. This ambivalence consists of conflicting messages about female athletes; positive portrayals of sportswomen are combined with subtly negative suggestions that trivialize or undercut the women’s efforts. Such trivialization is a way of denying power to women. The authors conclude by asserting that sport and leisure educators have an ethical obligation to redress the imbalance of power in the sporting world.

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Lyle J. Micheli

The majority of injuries in exercising children affect the musculoskeletal system. These injuries result from two mechanisms: single, acute macrotrauma or repetitive microtrauma. The injuries resulting from repetitive microtrauma—overuse injuries—appear to be occurring with increased frequency in this age group. A number of risk factors for overuse injury from exercise have been identified, including training error, muscle imbalance, anatomic malalignment, footwear, surface, nutritional factors, and cultural factors. The development of scientific criteria for exercise prescription in this age group that will enhance fitness and avoid injury awaits techniques for noninvasive assessment of musculoskeletal tissue fitness. In the interim, many of these injuries can be prevented or decreased in severity by slow progression of exercise intensity and qualified adult supervision.

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Nancy I. Williams, Clara V. Etter and Jay L. Lieberman

An understanding of the health consequences of abnormal menstrual function is an important consideration for all exercising women. Menstrual disturbances in exercising women are quite common and range in severity from mild to severe and are often associated with bone loss, low energy availability, stress fractures, eating disorders, and poor performance. The key factor that causes menstrual disturbances is low energy availability created by an imbalance of energy intake and energy expenditure that leads to an energy deficit and compensatory metabolic adaptations to maintain energy balance. Practical guidelines for preventing and treating amenorrhea in exercising women include evidence-based dietary practices designed to achieve optimal energy availability. Other factors such as gynecological age, genetics, and one’s susceptibility to psychological stress can modify an individual’s susceptibility to menstrual disturbances caused by low energy availability. Future research should explore the magnitude of these effects in an effort to move toward more individualized prevention and treatment approaches.

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Katherine Baird

This article examines the relationship between player compensation in college football and competitive balance on the field. It shows that National Collegiate Athletic Association rule changes restricting football-player compensation are not associated with an improvement in football’s competitive balance. Although college football is marginally more balanced than professional sports in any given year, an examination of cumulative records spanning numerous seasons proves college football to be as unbalanced as professional sports. The movement toward reducing player compensation, coincident with an increasing value to player talent, raises issues over how the financial gain from college football talent should be used. The significant degree of talent (and financial) imbalance among college football teams suggests that more attention should be paid to the determinants of talent distribution in college football.

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Yoram Epstein and Lawrence E. Armstrong

Body water and electrolyte balance are essential to optimal physiological function and health. During exercise, work, or high temperatures, a significant level of dehydration can develop, and the ratio of extracellular to intracellular fluid can change, despite an ample supply of water. Physical and cognitive performance are impaired at 1-2% dehydration, and the body can collapse when water loss approaches 7%. Because fluid needs and intakes vary, formulating one general guideline for fluid replacement is difficult. Knowing the amount of water lost in sweat may enable predicting fluid needs via mathematical models for industrial, athletic, and military scenarios. Sodium imbalance might result from excessive Na+ loss or from gross o verity dration. In most work or exercise lasting < 3-4 hr, the major concern is that fluid be available to prevent heat-related illnesses, which can be prevented if fluid and electrolyte losses are balanced with intake, using the recommendations presented.

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Micailah Brock and Sheri Huckleberry

This paper introduces the concept of dynamic isometrics in training athletes to improve core/postural-related movements while potentially decreasing the occurrence of injury manifested as lower back pain (LBP). Moreover, suggested resistance-training exercises are provided to guide the sport coach. Lower back pain is a common musculoskeletal injury that can be caused by imbalances between anterior and posterior muscle groups. Traditional exercises such as sit-ups and crunches are insufficient as preventatives because very few athletic movements are performed with weighted trunk flexion. Alternatively, sport coaches could implement dynamic isometric training, which closely reflects athletic activities, supports the principle of training specificity, improves balance and strength, and might decrease the occurrence of LBP (Hamlyn, Behm, & Young, 2007).

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Michael L. Naraine, Jessie Schenk and Milena M. Parent

This paper sought to examine the stakeholder network governance structures of two international and two domestic multisports events focusing on (a) exploring the structural connectedness of these networks and (b) illuminating powerful stakeholders vis-à-vis centrality and the ability to control the network’s flow. An exploratory, comparative case study design was built by means of 58 interviews and 550 archival materials. Findings highlight international sports events are sparsely connected networks with power concentrated in the organizing committee, government, and venue stakeholders, who broker coordination with other stakeholders. In contrast, domestic sport event organizing committees appear more decentralized as coordinating actors: Sport organizations, sponsors, and community-based stakeholders emerged as highly connected, powerful stakeholders. Domestic event governance decentralization highlights a potential imbalance in stakeholder interests through network flow control by multiple actors, while the governments’ centrality in international events demonstrates not only mode-dependent salience but also visibility/reputational risks and jurisdictional responsibilities-based salience.

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Leonard S. Jefferson and Scot R. Kimball

Gain or loss of skeletal muscle mass is due largely to the establishment of an imbalance between rates of protein synthesis and degradation. A key determinant of the rate of protein synthesis is translation initiation, a process regulated in part through binding of initiator methionyl-tRNA (met-tRNAi) and messenger RNA (mRNA) to a 40S ribosomal subunit. Either the met-tRNAi or mRNA binding step can become limiting for protein synthesis. Furthermore, the mRNA binding step can modulate translation of specific mRNAs with or without changes in the overall rate of protein synthesis. This report highlights molecular mechanisms involved in mediating control of the mRNA binding step in translation initiation. Particular attention is given to the effect of exercise on this step and to how the branched-chain amino acid leucine stimulates muscle protein synthesis after exercise. Potential mechanisms for exercise induced increase in muscle mass are discussed.

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Ruth Sibson

The under-representation of women in sport management has increasingly been recognized by government and nongovernment organizations, and there has been some attempt to redress the imbalance. Research has indicated, however, that the gendering of sport organizations is not simply a numbers’ game. The purpose of this study was to analyze the exercise of exclusionary power as an aspect of gender relations within a six member volunteer Board of Directors of an Australian local, grass-roots sport organization. Data were gathered using semistructured interviews, participant observation and documentary evidence over a 15-month period. This study identified that, although numerical underrepresentation of men or women on this Board was not an issue for either sex, exclusionary power was exercised in a number of overlapping ways which ultimately limited the participation, input, and influence of its female members.