bluuebunny/crossref_metadata_2025 huggingface dataset:
Power Patterns of the Leg during the Recovery Phase of the Sprinting Stride for Advanced and Intermediate Sprinters
Authors: Vardaxis Vassilis , Hoshizaki T. Blaine
Published: August 2016

This paper describes and interprets joint and segmental power patterns as functional characteristics of the leg movement in terms of generation, absorption, and transfer of power during the recovery phase of the sprinting stride. In addition, a comparison of the power patterns between advanced and intermediate sprinters was undertaken. Two advanced and two intermediate sprinters, each executing six trials of a 100-m dash, served as subjects. The results revealed that the power patterns for both the advanced and intermediate sprinters were similar in shape, depicting the same number of power phases. The hip joint musculature acted primarily as a power generator in comparison to the knee muscles, which acted mainly as absorbers (controllers) during the recovery phase of the sprinting stride. Differences between ability levels were identified using peak power values, with the advanced sprinters producing higher peak powers earlier in the recovery phase.
Bar Path and Force Profile Characteristics for Maximal and Submaximal Loads in the Bench Press
Authors: Wilson Gregory J. , Elliott Bruce C. , Kerr Graham K.
Published: August 2016

The bar movement characteristics of 10 elite powerlifters were analyzed while bench pressing a maximum load and a submaximal load in a simulated competition using high-speed cinematography. Significant differences in bar path and alterations to the general force profile of movement were evident as the load was increased. These movement discrepancies resulted in the following conclusions being drawn with reference to the bench press movement: (a) The movement pattern adopted during the performance of an 81 % maximum load was not specific to that which was utilized during the maximal load. (b) Based upon the concepts of specificity of training and testing, the use of the popular one-repetition maximum test to quantify strength changes derived from submaximal training appeared invalid. This occurrence is further accentuated when the testing protocol is conducted on a bench press machine. (c) The design of “isotonic” bench press machines appeared to be load specific. Further, the development of bench press machines that would allow a number of bar paths to be pursued appear to represent a significant improvement over existing models.
Finite Element Modeling of a Tennis Racket with Variable String Patterns and Tensions
Authors: Widing Mary Ann Bitz , Moeinzadeh Manssour H.
Published: August 2016

Finite element techniques were applied in a model of a tennis racket. Linear curved elements were used on the frame of the racket. Nonlinear cable elements were used on the strings. The model allows changing material properties and frame geometry, as do traditional models. Unlike traditional models, however, this model has the flexibility to change the string pattern and string tensions, as the strings are modeled discretely. Sample runs revealed information on the relationship between racket parameters and racket behavior such as deformations, stresses, and reaction forces. The results of the model showed that increasing string tension decreases racket deformation as string tension stiffens the racket. Increased string tension also decreases maximum hand reaction forces but increases stresses.
3-D Analysis of Yurchenko Vaults Performed by Female Gymnasts During the 1988 Seoul Olympic Games
Authors: Kwon Young-Hoo , Fortney Virginia L. , Shin In-Sik
Published: August 2016

Two of the most frequently performed vaults in the 1988 Olympic Games in Seoul were selected for 3-D cine-photogrammetry analysis: the Yurchenko layout with full twist and the Yurchenko layout. The performances included 20 vaults with the highest performance scores: 10 Yurchenko layout with Ml twist (YLF) and 10 Yurchenko layout (YL) vaults, which were performed in the women’s team optional competitions. The YLF group earned higher performance scores than the YL group. Average vaulting times were similar for the groups, but the YLF group showed shorter board and horse contact times and longer postflight times. The projectile motion variables were critical for better performance in the YLF group. Higher vertical velocity at horse takeoff was achieved mainly by minimizing its (Vv) loss during horse contact. The YL group showed the importance of angular momentum for better performance, with the normalized angular momentum during postflight being the critical variable for the YL vault.
Analysis of Male and Female Olympic Swimmers in the 100-Meter Events
Authors: Kennedy Patrick , Brown Peter , Chengalur Somadeepti N. , Nelson Richard C.
Published: August 2016

The performance of male and female swimmers (N = 397) competing in the preliminary heats of the four 100-meter swimming events during the Seoul Olympic Games was videotaped and later analyzed to determine stroke rate (SR) and stroke length (SL). These data were combined with age, height, and final time (FT) values for statistical analyses which included the relationships among these variables, comparison of male and female performance, and assessment of differences in the four events. The results revealed the following ranges of correlations between SR and SL (rs from −0.65 to −0.90), SL and FT (rs from −0.32 to −0.80), height and SL (0.19 to 0.58), and age and FT (-0.16 to −.051). The factor of SL was identified as the dominant feature of successful swimming performance. The men were older and taller, had longer stroke lengths and higher stroke rates (two of four events), and swam faster than the women. The differences in final times across the four events (freestyle fastest, breaststroke slowest) were due to specific combinations of SR and SL, with neither parameter being consistently dominant.
Kinetic and Kinematic Characteristics of 10-m Platform Performances of Elite Divers: II—Reverse Takeoffs
Authors: Miller Doris I. , Jones Ian C. , Pizzimenti Marc A. , Hennig Ewald , Nelson Richard C.
Published: August 2016

Takeoffs for 10-m platform dives from the reverse group at the 1986 World Championships and 1989 FINA Cup were analyzed to provide insights into their kinetic and kinematic characteristics. As with back takeoffs, the major changes in both linear and angular momentum occurred during final weighting (i.e., upward acceleration). Vertical velocities at last contact were higher for reverse dives than reverse multiple somersaults, and different moment-of-force patterns were associated with increased rotational requirements. Last-contact vertical velocities were less for reverse rotating dives than corresponding dives from the back group. Although last-contact horizontal velocities for the two groups were not statistically different, the horizontal acceleration patterns of the three composite body segments were near mirror images of one another. Finally, implications of a resultant head velocity of 10 m/s when passing the leading edge of the platform in reverse multiple somersaulting dives were considered.
Landing Leg Motion and Performance in the Horizontal Jumps I: The Long Jump
Authors: Koh Timothy J. , Hay James G.
Published: August 2016

The motions of the landing leg in the final three strides of the approach in the long jump are described, as are the relationships of these landing leg motions with performance. Film analysis of 19 elite male long jumpers competing in the 1986 and 1987 TAG (U.S. national) Championships showed that backward sweeping, or “active,” landings were used in each stride considered. However, the landing in the last stride was less active than those in the two preceding strides. A mathematical model showed that muscle action reduced the forward horizontal velocity of the landing foot in each landing. There were no statistically significant correlations of measures of landing leg motion with measures of performance. However, there was some indication that landing leg motion plays a role in lowering the center of gravity in the second-last stride and that this lowering increases the distance of the jump. There was also some indication that placing the landing foot well forward of the body at the end of the last stride benefits the distance of the jump, perhaps by promoting the development of vertical velocity during the support phase of the jump. This appears to be more important than minimizing the loss in horizontal velocity during the support phase of the jump.
Changes in Running Pattern during a Treadmill Run to Volitional Exhaustion: Fast versus Slower Runners
Authors: Siler William L. , Martin Philip E.
Published: August 2016

In order to compare fast and slow runners with respect to the relative timing of the compensations they make to maintain a given running velocity during a prolonged effort, coordinate data were collected periodically for 9 fast and 10 slow volunteers performing a treadmill run to volitional exhaustion at a speed approximating their 10-km race pace. Statistically significant but small changes were noted in the average stride length, range of motion at the thigh, maximum thigh flexion, maximum knee extension, maximum knee flexion, and head-neck-trunk segment (HNT) angle at maximum thigh extension. No statistically significant differences were detected, however, with regard to the relative timing of the compensations demonstrated by the two groups. It was concluded that runners demonstrate subtle compensations in running pattern as they approach volitional exhaustion. In addition, it was concluded that the performance level of the runners as reflected by the ranges of 10-km run performance used in this investigation does not affect the relative timing of the compensations. Finally, it appears that some individuals are more sensitive to the effects of fatigue as evidenced by extreme compensations in running pattern.
Mechanics and Biomechanics of Rowing: A Review
Authors: Zatsiorsky Vladimir M. , Yakunin Nikolai
Published: August 2016

Despite relatively numerous studies, the biomechanics of rowing remains poorly understood. Much of the data is contradictory and, worse still, there appears to be a lack of consensus on the mechanical background of rowing, which leads to different approaches to the measurement of a number of parameters known by the same terms. This makes direct comparison impossible. For this reason, the present review divides the discussion of relevant biomechanical problems into two stages. The first stage involves the construction of mechanical models of the rowing element under consideration, compilation of equations, and determination of parameters used in these equations. In the second stage, experimentally obtained empirical data on these parameters are discussed.
Accuracy of Derived Ground Reaction Force Curves for a Rigid Link Human Body Model
Authors: Sanders Ross H. , Wilson Barry D. , Jensen Robert K.
Published: August 2016

This study investigated whether force data could be derived accurately using segment inertia data determined by the elliptical zone method (Jensen, 1976), automatic digitizing from high-speed video using a Motion Analysis VP110 system, and for an activity that does not require flexion of the thorax. The criterion fonctions were the force-time records of the jumps recorded at 500 Hz by a Kistler 9281B force platform. A second-order Butterworth digital filter was used to smooth the derived data, with frequency cutoffs being selected on the basis of root mean square error of the smoothed function with respect to the criterion force function. In a second procedure, the criterion function was the directly measured force-time record after filtering with a second-order Butterworth digital filter at 5 Hz to remove the high frequency part of the force signal. The closeness of fit of the derived data to the low frequency part of the criterion force was then assessed. It was concluded that, using the techniques described, the low frequency components of the ground reaction forces of drop jumps could be derived accurately.
A Perturbation Study of Lower Extremity Motion during Running
Authors: Van Woensel Wilbert , Cavanagh Peter R.
Published: August 2016

The present study explored kinematic adaptation in the lower extremity to running in shoes with 10° valgus and varus midsole perturbations. Rearfoot motion and knee flexion/extension data on nine subjects were collected using a Selspot II system during treadmill running in the two test shoes and in a neutral shoe condition. Maximum pronation was significantly altered by an amount approximately the same as the shoe perturbation, but there was no substantial adaptation in the amount of knee flexion. From the rearfoot patterns it was inferred that time to maximum pronation may be an unreliable variable to describe the pattern of rearfoot motion; the two-phase profile using rearfoot velocity may be more useful. It was concluded that certain subtle sagittal plane kinematic adaptations in timing and velocity patterns did occur at the knee in response to the shoe perturbations.
Dynamics of the Interactions between Ball, Strings, and Racket in Tennis
Authors: Leigh Donald C. , Lu Wei-Yang
Published: August 2016

The dynamical interactions in tennis between ball, strings, and racket, during ball impact and immediately after, are modeled by a system of nonlinear ordinary differential equations that include both damping and elastic properties. During impact, the time history of the deflections, velocities, and forces in all parts of the system were calculated. Some simple experiments were done to determine the elastic and damping properties of the ball and strings, and to verify the theory in the case of a ball rebounding from the strings of a clamped racket head. Among the findings is that there is a trampoline effect even for a clamped racket head. Most interesting is that the rebound velocity of the ball can be increased, the mechanical energy transmitted to the racket can be reduced, and the maximum force transmitted to the holder of the racket can be reduced, all by increasing the damping in the racket.
Identities at Youth Sporting Events: A Critical Discourse Analysis
Authors: Meân Lindsey J. , Kassing Jeffrey W.
Published: August 2016

The purpose of this study was to examine identity and spectator/fan communication at youth sporting events. Data were collected through naturalistic observation of 44 youth sporting events. The median age range of the athletes was 6–11 years. Critical discourse analysis revealed the enactment of overlapping and conflicting identities (sports fan/spectator, coach, and parent) and the re/production of the ideology of winning (at all costs) and aggressive competition, rather than participation, support, and “unconditional” encouragement. In particular, the enactment or performance of sports identities, including identification with athletes, was observed to overlap with the enactment of parental identities and identification with children in ways that suggested that the salient issue was enhancement of parent self-categorization as sports spectator/fan, coach, and parent of a great athlete through the success of the child-athlete. That is, talk and identity performance were less about the children and more about parents’ identities.
Cinema Sports News (1940–1944): Between Factual Information and Propaganda
Authors: Birot Ludovic , Pecout Christophe , Cooper Coyte
Published: August 2016

The aim of this study was to analyze the cinema news produced during the German occupation of France (1940–1944) to better understand how information and news about sports were used to disseminate propaganda. Sports held a much bigger place in the cinema news of that time than in today’s televised news. Given the keen interest in sports information shown by the Nazi propagandists, the authors sought to determine how competitive sports and, more broadly, athletic practices were used by the German Reich and the Vichy government to advance propagandist goals. They found that sports information was presented in 2 manners. For spectator sports, a strategy of news “screening” was used to prevent unwanted images from national and international competitive matches from being seen. For the sports practiced by the French population, films dealing with these sports were made. Both types of documentary film were found to have propagandist goals, with images manipulated to change the population’s lifestyles to better serve the political regime in place.
Offensiveness of Native American Names, Mascots, and Logos in Sports: A Survey of Tribal Leaders and the General Population
Authors: Laveay Fraser , Callison Coy , Rodriguez Ann
Published: August 2016

The pervasiveness of media coverage of sports teams with American Indian names and imagery has arguably supported stereotypical beliefs of those referenced. Past research investigating opinions on sports teams using American Indian themes has been inconsistent in findings and drawn criticism for lacking valid samples of Native Americans. Through a survey of National Congress of American Indians leaders (n = 208) and random U.S. adults (n = 484), results reveal that Native Americans are more offended by sports teams employing American Indian imagery, as well as more supportive of change, than is the general public. Investigation of how demographic characteristics influenced perceptions show that although age and education level have little influence, political party affiliation does correlate with opinions, with those voting Democrat viewing the teams with American Indian names, logos, and mascots as most offensive and in need of change.
Expert Teachers’ Instructional Communication in Golf
Authors: Webster Collin A.
Published: August 2016

Expert golf instructors self-monitor their instruction and communication more than any other aspects of their teaching (Schempp, McCullick, Busch, Webster, & Sannen-Mason, 2006). Despite its apparent importance, however, the communication of expert golf instructors has received little investigative attention. The purpose of this study was to examine the instructional communication behaviors of 4 of the most highly accomplished golf instructors in the United States. Ladies Professional Golf Association instructors who met criteria for expert teaching (Berliner, 1994) and 4 students participated in the study. Videotaping, stimulated recall, and semistructured interviews were used to collect data on the teachers’ immediacy, communication style, and content relevance behaviors. Data were analyzed using modified analytic induction (Bogdan & Biklen, 1992). Findings indicated that the experts adapted their communication behaviors in ways that fit students’ learning preferences, personal experiences, and lesson goals. The findings resonate with previous research on expert teaching in terms of experts’ instructional flexibility.
To Build or Not to Build: Examining the Public Discourse Regarding St. Petersburg’s Stadium Plan
Authors: Mondello Michael J. , Schwester Richard W. , Humphreys Brad R.
Published: August 2016

Major League Baseball’s Tampa Bay Rays have proposed constructing a facility on the St. Petersburg waterfront. The projected cost of this stadium is $450 million, which will be financed partially by the Rays’ ownership. The remaining cost will be financed through tax revenues generated from the private redevelopment of Tropicana Field—the Rays’ current facility. Using content analysis, this article examines the public discourse regarding the proposed stadium. A pillar of controversy surrounding the stadium plan centers on opportunity-cost issues. Furthermore, in the context of the public-good argument, there is empirical evidence among bloggers that the stadium would stimulate awareness, improve the city’s image, or simply give the city a platform to showcase its amenities. This study aimed to provide a better understanding of the prevailing themes characterizing support for or opposition to this stadium plan and generate testable research hypotheses.
Message Boards and the Fantasy Sport Experience
Authors: Ruihley Brody J. , Hardin Robin L.
Published: August 2016

Fantasy sport joins competition, sport knowledge, and socialization into one interactive sport activity. This research specifically focuses on the socialization aspects of the activity. This analysis addresses overall satisfaction in fantasy sport, future intentions to return to the activity, and reasons why fantasy sport users (FSUs) do or do not use message boards. Data were collected from 322 FSUs in a questionnaire format using quantitative-scale items and qualitative open-ended questions. The results indicate 62.1% (n = 200) of the sample using message boards in their fantasy sport experience. Reasons for their use were based on the themes of logistical conversation, socializing, surveillance, and advice or opinion. FSUs chose not to use message boards for reasons based on no interest, information, time, and alternative options. Other results indicate that those using message boards have higher overall satisfaction and future use intentions than those not using message boards. This suggests that message boards enhance the fantasy sport experience.
Real Madrid Football Club: Applying a Relationship-Management Model to a Sport Organization in Spain
Authors: García César
Published: August 2016

Real Madrid Football Club is today the richest sport team in the world and the third most valuable sport brand, according to the latest rankings (e.g., Deloitte, 2010; Forbes 2009). This scholarly commentary proposes the application of a relationship management model of building long-lasting relationships with fans as the main key of Real Madrid’s success. Results of this study highlight that, under the presidency of Florentino Pérez, a public relations approach has been integrated into every strategic decision including the recruitment of players with media appeal; the use of event planning, Internet, social media, promotional tours, and publications; and the display of Real Madrid’s own audiovisual media. The adoption of this model has proven successful despite poor sports results.
Gender Dynamics in Producing News on Equality in Sports: A Dual Longitudinal Study of Title IX Reporting by Journalist Gender
Authors: Kaiser Kent
Published: August 2016

This 2-part longitudinal study uses quantitative content analysis of newspapers to investigate gender dynamics in producing news on equality in sports. It analyzes differences in Title IX coverage by reporter gender to determine whether female journalists advocated more aggressively for women’s equality than their male counterparts did. The study’s first part uses content analysis of volume and placement of articles about Title IX, by journalist gender, and discusses the implications of how patterns of volume and placement have changed over time. The second part identifies advocacy and opposition frames used in the conflict over Title IX; applies content analysis of frames used, by journalist gender; and discusses implications of reporting differences and changes over time for equality. Evidence suggests that, first, social control; then a feminist perspective; and, most recently, a postfeminist worldview among female journalists influenced coverage of the law.
Nationalism, Identity, and Fan Relationship Building in Barcelona Football Club
Authors: García César
Published: August 2016

Historically, Barcelona Football Club (BFC) has represented one of the pillars of Catalan identity, which earned it the slogan “more than a club.” In recent times, especially under the presidency of Joan Laporta, management has radicalized the club’s political positions by using BFC as a platform to openly promote the independence from Spain of the Catalan region. Despite the fact that most Barcelona fans in Catalonia, as well as in the rest of Spain, have much more moderate political positions, the radicalization of BFC does not appear to have eroded the relationship-building process with Barcelona fandom. This article argues that BFC as an institution still maintains a good relationship with its fans because the social, as well as individual, identity provided by allegiance to a soccer club such as BFC is ultimately more important to members and fans than the club’s political positions.
Journalists and Olympic Athletes: A Norwegian Case Study of an Ambivalent Relationship
Authors: Kristiansen Elsa , Hanstad Dag Vidar
Published: August 2016

This case study explores the relationship between media and sport. More specifically, it examines the association (i.e., the contact and communication) between Norwegian journalists and athletes during the 2010 Olympic Winter Games in Vancouver, Canada. Ten athletes and three journalists were interviewed about their relationship. To regulate and improve the journalist–athlete relationship during special events like the Olympics, media rules have been formulated. In regard to the on-site interactions, they accepted that they are working together where one was performing and the other reporting the event “back home.” While the best advice is to be understanding of the journalists’ need for stories and inside information, the media coverage was perceived as a constant stress factor for the athletes. However, because of the media rules the athletes were able to keep their distance but one athlete did comment: “You will not survive if you take it personally.”
Covering the Scandal in 140 Characters: A Case Study of Twitter’s Role in Coverage of the Penn State Saga
Authors: Sanderson Jimmy , Hambrick Marion E.
Published: August 2016

This case study explored how sports journalists used Twitter to cover allegations about former Penn State University assistant football coach Jerry Sandusky sexually abusing young boys. A content analysis of 1652 tweets from 151 sports journalists was conducted. Analysis revealed that sports journalists used Twitter in the following ways: a) offering commentary, b) breaking news, c) interactivity, d) linking to content, and e) promotion. The results suggest that Twitter serves as an additional venue for sports journalists to frame stories; however, their behavior in this venue blurs professional and personal boundaries as they mock fans and promote their competitors. The analysis further suggests that the immediacy with which news breaks on Twitter places sports journalists and sports media organizations into a dialectic between “being first” and “being accurate” when reporting news.
Identity in Twitter’s Hashtag Culture: A Sport-Media-Consumption Case Study
Authors: Smith Lauren Reichart , Smith Kenny D.
Published: August 2016

This case study, using social-identity theory as a framework, examines how sport consumers and producers used different identifiers to engage in conversation during the final games of the 2012 College World Series of baseball. Five major hashtags were noted for each baseball team as primary identifiers; users fit in 3 main groups and subgroups. The analysis of tweets revealed 5 major themes around which the conversations primarily revolved. The study has implications for social-identity theory and team identification, as well as broader implications for audience fragmentation and notions of the community of sport.
A Phenomenological Investigation Into How Twitter Has Changed the Nature of Sport Media Relations
Authors: Gibbs Chris , Haynes Richard
Published: August 2016

This article uses the phenomenological method to explain how Twitter has changed the nature of sport media relations. The research was based on semistructured interviews with 18 Canadian and U.S. sport media professionals having an average 16 yr of experience. This exploratory study uses the lived experience of sport media professionals to identify 3 clusters that help explain how Twitter has changed the nature of sport media relations: media landscape, “mechanical” job functions, and sport media relations. The results of this research are significant because they help explain how the practices and norms related to the role of sport media relations are changing as a result of Twitter. This research presents a new argument: that Twitter has flattened the sport hierarchy and could be considered the most influential social-media platform in sport today.
Insufficient Dietary Carbohydrate during Training: Does It Impair Athletic Performance?
Authors: Sherman William M. , Wimer Gregory S.
Published: August 2016

It is well established that adequate bodily carbohydrate reserves are required for optimal endurance. Based on this fact, it has been hypothesized that consumption of a diet with a high percentage of carbohydrate energy will optimize training adaptations and athletic performance. Scrutiny of the literature, however, does not strongly support the hypothesis that short-term or long-term reductions in dietary carbohydrate energy impairs training or athletic performance. Additional studies with well devised training protocols and performance tests are necessary to prove or disprove the hypothesis that a high carbohydrate energy diet is necessary to optimize training adaptations and performance. Because dietary carbohydrate contributes directly to bodily carbohydrate reserves, and because a high carbohydrate energy diet does not impair athletic performance, it remains prudent to advise athletes to consume a diet with a high carbohydrate energy content.
Nutritional Considerations for Ultraendurance Performance
Authors: Applegate Elizabeth A.
Published: August 2016

The nutritional considerations of the ultraendurance athlete center around proper caloric and nutrient intake during training as well as adequate energy and fluid replacement during competition to maintain optimal performance. Energy needs of ultraendurance athletes during training vary widely, depending upon duration, intensity, and type of exercise training. These athletes may train several hours daily, thus risking inadequate caloric intake that can lead to chronic fatigue, weight loss, and impaired physical performance. It is not known whether protein needs are increased in ultraendurance athletes as a result of extended exercise training. Additionally, micronutrient needs may be altered for these athletes while dietary intake is generally over the RDA because of high caloric intake. Prior to competition, ultraendurance athletes should consider glycogen supercompensation and a prerace meal eaten 4 hrs before as a means of improving performance. Carbohydrate feedings during prolonged exercise can significantly affect performance. During events lasting over several hours, sodium sweat losses and/or the consumption of sodium-free fluids may precipitate hyponatremia.
Influence of a Carbohydrate-Electrolyte Beverage on Performance and Blood Homesstasis during Recovery from Football
Authors: Criswell David , Powers Scott , Lawler John , Tew John , Dodd Stephen , Iryiboz Yryik , Tulley Richard , Wheeler Keith
Published: August 2016

This study compared the efficacy of a 7% glucose polymer beverage containing electrolytes (GP) versus a nonnutrient, nonelectrolyte placebo (P) in maintaining blood homeostasis during recovery from football and determined whether consumption of the GP beverage improved anaerobic performance immediately after football competition when compared with the placebo. Forty-four high school football players participated in a 50-play scrimmage designed to simulate game conditions. At each of six periods before and during the scrimmage, players consumed 170 ml of the GP or P beverage. Eight maximal-effort 40-yd sprints (40-sec rest intervals) were performed before and after the scrimmage to assess the decrement in anaerobic performance from the scrimmage. Venous blood samples were drawn before and after the scrimmage and analyzed. The pre- to postscrimmage differences in mean and peak sprint velocities did not differ between treatments, nor did body weight and plasma. In contrast, the percent decrease in plasma volume was significantly greater in the P group. Postscrimmage increases in glucose and insulin were greater in the GP group. These data suggest that CHO-electrolyte drinks do not prevent a decline in anaerobic performance when compared to water, but a CMO-electrolyte drink is more effective in maintaining PV than water during recovery from anaerobic exercise.
The Effects of Ingesting Polylactate or Glucose Polymer Drinks during Prolonged Exercise
Authors: Fahey Thomas D. , Larsen James D. , Brooks George A. , Colvin William , Henderson Steven , Lary Darrel
Published: August 2016

Five trained, fasted male cyclists rode a cycle ergometer three times at 50% of ,max for 180 min. Using a balanced order, double-blind procedure,subjects were given either a solution containing polylactate (PL: 80% polylactate, 20% sodium lactate, in 7% solution with water), glucose polymer (GP: multidextrin in 7% solution with water), or control (C: water sweetened with aspartame) 5 min before exercise and at 20-min intervals during exercise. Venous blood samples were taken at rest and at 20-min intervals during exercise. In general, PL and GP rendered similar results except that pH and bicarbonate () were higher in PL. There were no differences between treatments in perceived exertion, sodium, potassium, chloride, lactate, heart rate, oxygen consumption, rectal temperature, or selected skin temperatures. These data show that polylactate may help maintain blood glucose and enhance blood buffering capacity during prolonged exercise and could be a useful component in an athletic fluid replacement beverage.
Seasonal Changes in Female Athletes' Diets
Authors: Nutter June
Published: August 2016

Dietary intakes of 24 female athletes in various sports were compared inseason and postseason to those reported by 24 nonathletes during the same time period. Diets were analyzed for energy, carbohydrate, fat, protein, vitamins A and C, thiamin, riboflavin, niacin, folacin, calcium, and iron. During the study, the athletes' and nonathletes' diets were similar. Their energy intakes were lower than recommended while their iron and calcium intakes were marginal (less than 70% of the recommended dietary allowance). Although few dietary changes were observed, the nonathletes' diets changed more than those of the athletes during the study. Both groups reduced their energy intakes but only the nonathletes' reduction was significant. Initially many subjects were dieting. More subjects reported dieting during the second recording period. These results suggest that the desire to be thin may influence dietary intakes of female athletes more than changes in exercise training.
Influence of Diet and Exercise on Energy Expenditure—A Review
Authors: Van Zant R. Scott
Published: August 2016

Maintenance of a healthy body weight results from equating total enegy intake to total energy expenditure (resting metabolic rate, RMR, the thermic effect of feeding, TEF; the thermic effect of activity, TEA, and adaptive thermogenesis, AT). Dietary quantity and composition and acute and chrvnic exercise have been shown to influence all components of total energy expenditure. This paper reviews the effects of exercise and diet on energy expenditure and, ultimately, energy balance. Overnutrition increases RMR and TEF while undernutrition decreases them. Carbohydrate and protein oxidation is closely tied to intake whereas fat oxidation does not closely parallel fat intake. Thus excess fat intake is likely to lead to fat storage. Acute endurance exercise at >70% increases postexercise RMR and TEF. Chronic exercise training may increase RMR while also increasing TEF. Review of the research indicates that energy balance may best be achieved by consuming an energy appropriate, low fat diet complemented by endurance exercise.
Effects of Phosphate Loading on Metabolic and Myocardial Responses to Maximal and Endurance Exercise
Authors: Kreider Richard B. , Miller Gary W. , Schenck Deborah , Cortes Charles W. , Miriel Victor , Somma C. Thomas , Rowland Pam , Turner Caroll , Hill Dawn
Published: August 2016

Six trained male cyclists and triathletes participated in a double blind study to determine the effects of phosphate loading on maximal and endurance exercise performance. Subjects ingested either 1 gm of tribasic sodium phosphate or a glucose placebo four times daily for 3 days prior to performing either an incremental maximal cycling test or a simulated 40-km time trial on a computerized race simulator. They continued the supplementation protocol for an additional day and then performed the remaining maximal or performance exercise test. Subjects observed a 17-day washout period between testing sessions and repeated the experiment with the alternate supplement regimen in identical fashion. Metabolic data were collected at 15-sec intervals while venous blood samples and 2D-echocardiographic data were collected during each stage of exercise during the maximal exercise test and at 8-km intervals during the 404cm time trial. Results indicate that phosphate loading attenuated anaerobic threshold, increased myocardial ejection fraction and fractional shortening, increased maximal oxidative capacity, and enhanced endurance performance in competitive cyclists and triathletes.
Vitamin C Intake and Lipid Profiles of Competitive Male and Female Bodybuilders
Authors: L. Bazzarre Terry , Kleiner Susan M. , Ainsworth Barbara E.
Published: August 2016

This research compared nutrient intake data with blood lipids and anthropometric data. Height, weight, and seven skinfolds were collected 3 days prior to competition at the official weigh-in. The lipids measured were total cholesterol (TC), HDL-cholesterol (HDL-C), and the HDL2 and HDL3 cholesterol subfractions. The subjects were 17 males and 17 females. Descriptive data are presented as means and standard deviations of the means. Protein, fat, and carbohydrate provided about 40, 12, and 48%, respectively, of total energy intake; vitamin C was >200 mgfday. Only dietary fat was significantly (p < 0.05) associated with TC for females. Fiber was significantly associated with HDL-C and HDL2-C for males and with HDL-C for females. Vitamin C was significantly associated with HDL-C, HDL2-C, and HDL3-C for males, and with HDL-C and HDL3-C for females. These findings are consistent with those reported by Bazzarre et al. in farmers and suggest that vitamin C may favorably influence HDL-C metabolism.
Carbohydrate Intake and Recovery from Prolonged Exercise
Authors: Fallowfield Joanne L. , Williams Clyde
Published: August 2016

The influence of increased carbohydrate intake on endurance capacity was investigated following a bout of prolonged exercise and 22.5 hrs of recovery. Sixteen male subjects were divided into two matched groups, which were then randomly assigned to either a control (C) or a carbohydrate (CHO) condition. Both groups ran at 70% VO2max on a level treadmill for 90 min or until volitional fatigue, whichever came first (T1), and 22.5 hours later they ran at the same % VO2max for as long as possible to assess endurance capacity (T2). During the recovery, the carbohydrate intake of the CHO group was increased from 5.8 (±0.5) to 8.8 (±0.1) g kg-1 BW. This was achieved by supplementing their normal diet with a 16.5% glucose-polymer solution. An isocaloric diet was prescribed for the C group, in which additional energy was provided in the form of fat and protein. Run times over T1 did not differ between the groups. However, over T2 the run time of the C group was reduced by 15.57 min (p<0.05), whereas those in the CHO group were able to match their T1 performance. Blood glucose remained stable throughout Tl and T2 in both groups. In contrast, blood lactate, plasma FFA, glycerol, ammonia, and urea increased. Thus, a high carbohydrate diet restored endurance capacity within 22.5 hrs whereas an isocaloric diet without additional carbohydrate did not.
Practices and Recommendations of Sports Nutritionists
Authors: Grandjean Ann C.
Published: August 2016

A three-part questionnaire was used to identify professionals in sports nutrition and survey their recommendations on various aspects of sports nutrition. The majority of respondents were women. Over half of the sample reported working in sports nutrition for 6 years or less, and 72% indicated that 40% or less of their job is dedicated to sports nutrition. A portion of the questionnaire assessed the subjects' opinions on various sports nutrition topics. Statements on water and electrolytes generated the most agreement while statements on protein generated the least agreement. There was a positive correlation (p~0.004) between level of education and whether or not the respondents recommended glycogen loading, and a positive correlation (p~0.008) between the subjects' use of dietary supplements and the fact that they recommended supplements to the athletes they counseled. The majority of professionals in this study worked with recreational athletes and were more concerned about encouraging a healthy diet than improving athletic performance.
Weight Loss and Weight Cycling in Amateur Wrestlers: Implications for Performance and Resting Metabolic Rate
Authors: Horswill Craig A.
Published: August 2016

Amateur wrestlers practice weight loss for ergogenic reasons. The effects of rapid weight loss on aerobic performance are adverse and profound, but the effects on anaerobic performance are equivocal Anaerobic performance—strength and power—may be the most relevant type of performance to the wrestler. Maintenance of or even small decrements in anaerobic performance may translate into improvements in performance relative to the weight class, the factor by which wrestlers are matched for competition. During the recovery period between the official weigh-in and competition, wrestlers achieve at least partial nutritional recovery, which appears to benefit performance. Successive bouts of (a) weight loss to make weight and (b) recovery for performance lead to weight cycling. There is speculation that weight cycling may contribute to chronic glycogen depletion, reductions in fat-free weight, a decrease in resting metabolic rate, and an increase in body fat. The latter two would augment the difficulty of losing weight for subsequent weigh-ins. Most research indicates that the suppressed resting metabolic rate with weight loss in wrestlers appears to be transient, but subsequent research is needed for confirmation.
Zinc Loss in Sweat of Athletes Exercising in Hot and Neutral Temperatures
Authors: Tipton Kevin , Green Nancy R. , Haymes Emily M. , Waller Mary
Published: August 2016

Zinc (Zn) loss from sweat of 9 male and 9 female athletes exercising under hot (35°C, HE) and neutral (25°C, ME) conditions was examined. Subjects exercised at 50% VO2max on a cycle ergometer for 1 hr during each trial. Cell-free sweat samples were analyzed for Zn by atomic absorption spectro-photometry. There was a significant interaction of time, gender, and temperature for whole-body sweat rates (WBSR). WBSR for males were higher during both trials and at each time. WBSR from the second half of exercise were higher than those from the first half for both sexes and temperature conditions. Sweat Zn concentration was higher in the NE than in the HE, but when the sweat rates were included, the rate of Zn loss was no different between HE and NE. Zn concentration of the sweat for the first half of exercise was over twice that of the second half. Sweat Zn concentration of the men was no different than that of the women; however, due to greater sweat rate, men had significantly higher Zn losses. Although total Zn losses are estimated to be relatively low compared to the RDA. exercise at moderate intensities may increase surface Zn losses.
Low-Dose Amino Asid Supplementation: No Effects on Serum Human Growth Hormone and Insulin in Male Weightlifters
Authors: Fogelholm G. Mikael , Näveri Hannu K. , Kiilavuori Kai T.K. , HärkÖnen Matti H.A.
Published: August 2016

Using a double-blind, crossover protocol, we studied the possible effects of a 4-day combined L-arginine, L-ornithine, and L-lysine supplementation (each 2 g/day, divided into two daily doses) on 24-hr level of serum human growth hormone (hGH) and insulin in 11 competitive weightlifters, ages 19 to 35 yrs. Three similar daily hGH peaks, seemingly preceded by a decrease in serum insulin concentration, were found during both amino acid and placebo supplementation. Supplementation did not affect the physiological variation of serum hGH concentration (treatment and treatment × time interaction: p=0.43–0.55). Analogously, serum insulin levels were not higher after amino acid supplementation. Therefore the ergogenic value of lowdose oral amino acid supplementation in increasing hGH or insulin secretion seems questionable.
Effects of Preexercise Candy Bar Ingestion on Glycemic Response, Substrate Utilization, and Performance
Authors: Alberici June C. , Farrell Peter A. , Kris-Etherton Penny M. , Shively Carol A.
Published: August 2016

This study examined the effects of preexercise candy bar ingestion on glycemic response, substrate utilization, and performance ie 8 trained male cyclists. The cyclists randomly ingested oee large milk chocolate bar (1CB), two large milk chocolate bars (2CB), or a placebo (P) 30 min prior to a 90-min cycle ride at 70% VO2max followed by a 33-W increase every 2 min until exhaustion (~10 min). Glucose decreased after 15 min of exercise but returned to preexercise values by 30 min of exercise. Glucose concentration for 2CB was significantly higher than for P and 1CB at exhaustion, Insulin concentration increased in response to ICB and 2CB and returned to preexercise values within 15 min of exercise. No significant differences were noted for free fatty acid (FFA) concentrations, Jactate concentrations, respiratory exchange ratio, total carbohydrate oxidation, or estimated fat and carbohydrate oxidation rates. Time to exhaustion was similar among the groups. The results suggest that the transient lowering of blood glucose observed with preexercise milk chocolate bar ingestion 30 min prior to exercise may not cause major metabolic perturbations that impair athletic performance in trained athletes performing moderately intense cycle exercise.
On Dancers and Diet
Authors: Sandri Susan Campbell
Published: August 2016

Dancers exhibit compliance problems in adopting advice from nutrition experts. Examination of the situation reveals an inherent culture clash between dancers and nutrition authorities. Dancers need safe methods of achieving an ultralean physique, but the recommendations of most nutritionists do not fit dancers* requirements. This manuscript is intended to provide the nutrition professional with insight into the dancer's needs and cultural/professional perspective on dieting. Dietary problems/disorders that are common among dancers are reviewed. Both general and specific recommendations are made for advising dancers and for designing their diets.
Nutrient Intake of Female Elite Athletes Suffering from Eating Disorders
Authors: Sundgot-Borgen Jorunn
Published: August 2016

This study assessed the nutrient intake and eating behavior in Norwegian female elite athletes suffering from eating disorders (ED) who met the criteria for anorexia nervosa (AN), anorexia athletica (AA), or bulimia nervosa (BN). The subjects included 7 AN, 43 AA, 42 BN, and 30 controls. Three-day and 24-hr food records were used to assess energy and nutrient intake. Results revealed that a significant number of AN and AA athletes have diets too low in energy and nutrients, the mean intake for energy and CHO being lower than recommended for active females. A significant number did not reach the protein level recommended for athletes. In addition, there were low intakes of several micronutrients, most notably calcium, vitamin D, and iron. The energy and nutritional inadequacy, combined with the use of purging, are of major concern since the athletes in this study were relatively young. It is unknown whether the abnormal eating pattern is a consequence of ED or is typical of top level athletes.