We investigated the effects of high pressure on the point of no return or the minimum time required for a kicker to respond to the goalkeeper’s dive in a simulated penalty kick task. The goalkeeper moved to one side with different times available for the participants to direct the ball to the opposite side in low-pressure (acoustically isolated laboratory) and high-pressure situations (with a participative audience). One group of participants showed a significant lengthening of the point of no return under high pressure. With less time available, performance was at chance level. Unexpectedly, in a second group of participants, high pressure caused a qualitative change in which for short times available participants were inclined to aim in the direction of the goalkeeper’s move. The distinct effects of high pressure are discussed within attentional control theory to reflect a decreasing efficiency of the goal-driven attentional system, slowing down performance, and a decreasing effectiveness in inhibiting stimulus-driven behavior.
Martina Navarro, Nelson Miyamoto, John van der Kamp, Edgard Morya, Ronald Ranvaud and Geert J.P. Savelsbergh
John van der Kamp
This study investigated whether soccer penalty-takers can exploit predictive information from the goalkeeper’s actions. Eight low- and seven high-skilled participants kicked balls in a penalty task with the goalkeeper’s action displayed on a large screen. The goalkeeper initiated his dive either before, at or after the ball was struck. The percentage of balls shot to the empty half of the goal was not above chance when the participants could only rely on predictive information. Gaze patterns suggested that the need to fixate the target location to maintain aiming accuracy hindered perceptual anticipation. It is argued that penalty-takers should select a target location in advance of the run-up to the ball and disregard the goalkeeper’s actions.
Previous research has identified specific differences in cognition between experts and novices in problem-solving domains. To address the question of whether similar distinctions exist among springboard divers, six differences in problem representation and four differences in procedural knowledge were studied in elite and nonelite springboard divers. Subjects reported their thoughts immediately following dive performance. Verbal reports were converted into problem representations and production rules. Analysis of the representations and production rules revealed differences between elite and nonelite divers consistent with distinctions found between expert and novice problem-solvers. Elite problem representations contained more higher order concepts than nonelite representations. Moreover, the elite representations were more richly embedded, containing more concepts, features, and interrelations than the nonelite representations. Also, elite divers cited more production rules than nonelite divers. Elite production rules displayed a greater degree of sophistication in discrimination, proceduralization, composition, and strengthening.
Katherine A. Beals and Amanda K. Hill
The purpose of this study was to examine the prevalence of disordered eating (DE), menstrual dysfunction (MD), and low bone mineral density (BMD) among US collegiate athletes (n = 112) representing 7 different sports (diving, swimming, x-country, track, tennis, field hockey, and softball) and determine differences in prevalence existed between athletes participating in lean-build (LB) and non-lean build (NLB) sports. DE and MD were assessed by a health, weight, dieting, and menstrual history questionnaire. Spinal BMD was determined via dual energy x-ray absorptiometry. Twenty-eight athletes met the criteria for DE, twenty-nine for MD, and two athletes had low BMDs (using a Z score below −2.0). Ten athletes met the criteria for two disorders (one with disordered eating and low BMD and nine with disordered eating and menstrual dysfunction), while only one athlete met the criteria for all three disorders. Using a Z score below −1.0, two additional athletes met the criteria for all three disorders and three more athletes met the criteria for a combination of two disorders. With the exception of MD, which was significantly more prevalent among LB vs. NLB sports (P = 0.053), there were no differences between the groups in the prevalence of individual disorders or combinations of disorders. These data indicate that the combined prevalence of DE, MD, and low BMD among collegiate athletes is small; however, a significant number suffer from individual disorders of the Triad.
Louise M. Burke, David B. Pyne and Richard D. Telford
Oral supplementation with creatine monohydrate (Cr.
Daniel Tan, Brian Dawson and Peter Peeling
This study aimed to quantify the hemolytic responses of elite female football (soccer) players during a typical weekly training session.
Ten elite female football players (7 field players [FPs] and 3 goalkeepers [GKs]) were recruited from the Australian National Women’s Premier League and asked to provide a venous blood sample 30 min before and at the immediate conclusion of a typical weekly training session. During this training session, the players’ movement patterns were monitored via a 5-Hz global positioning system. The blood samples collected during the training session were analyzed for iron status via serum ferritin (SF) analysis, and the hemolytic response to training, via serum free hemoglobin (Hb) and haptoglobin (Hp) measurement.
50% of the participants screened were found to have a compromised iron stores (SF <35 μg/L). Furthermore, the posttraining serum free Hb levels were significantly elevated (P = .011), and the serum Hp levels were significantly decreased (P = .005), with no significant differences recorded between the FPs and GKs. However, the overall distance covered and the movement speed were significantly greater in the FPs.
The increases in free Hb and decreases in Hp levels provide evidence that a typical team-sport training session may result in significant hemolysis. This hemolysis may primarily be a result of running-based movements in FPs and/or the plyometric movements in GKs, such as diving and tackling.
Ian C. Jones and Doris L. Miller
The running forward springboard approaches of 20 divers on the U.S. senior national diving team were analyzed using planar video analysis and accelerometer output; the purpose was to investigate kinematic responses of the springboard tip and divers' lower extremities to alterations in fulcrum setting. Divers executed jump takeoffs from a 1-m springboard with the fulcrum at their preferred setting as well as 0.144 m (two fulcrum numbers) forward and 0.144 m back from that location. Potential advantages of setting the fulcrum back further from the tip (as opposed to closer) included greater downward board tip vertical velocity at the beginning of takeoff, more time to generate angular momentum, and increased vertical velocity going into flight. However, setting the fulcrum further back required the diver to achieve longer hurdle flight durations and to reverse downward motion from a more flexed knee position. Accelerometer output in the absence of video was not beneficial as a means of providing immediate performance feedback for coaching purposes.
Elaine Tor, David L. Pease and Kevin A. Ball
The swimming start is highly influential to overall competition performance. Therefore, it is paramount to develop reliable methods to perform accurate biomechanical analysis of start performance for training and research. The Wetplate Analysis System is a custom-made force plate system developed by the Australian Institute of Sport—Aquatic Testing, Training and Research Unit (AIS ATTRU). This sophisticated system combines both force data and 2D digitization to measure a number of kinetic and kinematic parameter values in an attempt to evaluate start performance. Fourteen elite swimmers performed two maximal effort dives (performance was defined as time from start signal to 15 m) over two separate testing sessions. Intraclass correlation coefficients (ICC) were used to determine each parameter’s reliability. The kinetic parameters all had ICC greater than 0.9 except the time of peak vertical force (0.742). This may have been due to variations in movement initiation after the starting signal between trials. The kinematic and time parameters also had ICC greater than 0.9 apart from for the time of maximum depth (0.719). This parameter was lower due to the swimmers varying their depth between trials. Based on the high ICC scores for all parameters, the Wetplate Analysis System is suitable for biomechanical analysis of swimming starts.
David B. Pyne and Rick L. Sharp
The aquatic sports competitions held during the summer Olympic Games include diving, open-water swimming, pool swimming, synchronized swimming, and water polo. Elite-level performance in each of these sports requires rigorous training and practice to develop the appropriate physiological, biomechanical, artistic, and strategic capabilities specific to each sport. Consequently, the daily training plans of these athletes are quite varied both between and within the sports. Common to all aquatic athletes, however, is that daily training and preparation consumes several hours and involves frequent periods of high-intensity exertion. Nutritional support for this high-level training is a critical element of the preparation of these athletes to ensure the energy and nutrient demands of the training and competition are met. In this article, we introduce the fundamental physical requirements of these sports and specifically explore the energetics of human locomotion in water. Subsequent articles in this issue explore the specific nutritional requirements of each aquatic sport. We hope that such exploration will provide a foundation for future investigation of the roles of optimal nutrition in optimizing performance in the aquatic sports.
Karen H. Weiller, Catriona T. Higgs and Scott B. Martin
Sports are omnipresent in American society; available for viewing 24 hours a day and can constitute much of everyday life and conversation. Researchers have indicated that men and women relate to sport differently (Gantz & Wenner, 1991). Evidence shows males outnumber females in sport viewership, and in the past much of the sport programming to which we are exposed caters specifically to men. The purpose of the present study was to explore issues related to audience perception of the 1996 Olympic Games. Participants (125 males and 92 females) ranging from 18 to 40 years of age were administered a gender specific version of the Audience Perception Questionnaires (APQ) following viewing video segments of men’s and women’s competitions (i.e., basketball, gymnastics, swimming and diving, and volleyball). The two versions of the APQ were developed from current literature, and by employing a delphi technique to validate the APQ. Factor analyses resulted in four underlying media perception dimensions: Commentary Coverage, Gender Marking and Stereotyping, Hierarchy of Naming, and Verbal Descriptors. Results revealed perceptions of male and female athletes by the public are influenced to a great degree by gender.