Syncope during sports participation may serve as the first manifestation of cardiovascular disease that poses a risk for athletic training and competition. Other causes of syncope (vasovagal, dehydration) during physical activity may be more benign. The athlete who faints during sports deserves a comprehensive diagnostic evaluation that addresses the wide-ranging differential diagnosis involved. The case of a 14-year-old male with two syncopal spells during athletic training is presented to review the components of such a workup and subsequent management implications.
Thomas W. Rowland, Richard C. McFaul and David A. Burton
Catriona A. Burdon, Nathan A. Johnson, Phillip G. Chapman, Ahmad Munir Che Muhamed and Helen T. O’Connor
The aim of this study was to measure the effect of environmental conditions and aid-station beverage-cooling practices on the temperature of competitor beverages.
Environmental and beverage temperatures were measured at three cycling and two run course aid stations at the 2010 Langkawi, Malaysia (MA), and Port Macquarie, Australia (AU), Ironman triathlon events. To measure the specific effect of radiant temperature, additional fluid-filled (600 ml) drink bottles (n = 12) were cooled overnight (C) and then placed in direct sun (n = 6) or shade (n = 6) near to a cycle aid station at AU.
During both events, beverage temperature increased over time (p < .05) as environmental conditions, particularly radiant temperature increased (p < .05). Mean beverage temperature ranged between 14–26°C and during both events was above the palatable range (15–22°C) for extended periods. At AU, bottles placed in direct sunlight heated faster (6.9 ± 2.3 °C·h−1) than those in the shade (4.8 ± 1.1°C·h−1, p = .05).
Simple changes to Ironman aidstation practices, including shade and chilling beverages with ice, result in the provision of cooler beverages. Future studies should investigate whether provision of cool beverages at prolonged endurance events influences heat-illness incidence, beverage-consumption patterns, and competitor performance.
Arnaud Faupin, Philippe Gorce, Eric Watelain, Christophe Meyer and Andre Thevenon
The aim of this study was to investigate muscle activity, kinematic, and handgrip-force pattern generation during handcycling. One able-bodied participant performed a 1-min exercise test on a handcycle at 70 revolutions per minute. This article proposes an original data collection and analysis methodology that gathers synchronized kinematics, kinetics, and electromyography. Such data, which most often appear complex, are easily summarized using this methodology. This preliminary study has an new setup and offers good indications on the biomechanical pattern for handcycling movement analysis.
John S. Cuddy, Dustin R. Slivka, Walter S. Hailes, Charles L. Dumke and Brent C. Ruby
The purpose of this study was to determine the metabolic profile during the 2006 Ironman World Championship in Kailua-Kona, Hawaii.
One recreational male triathlete completed the race in 10:40:16. Before the race, linear regression models were established from both laboratory and feld measures to estimate energy expenditure and substrate utilization. The subject was provided with an oral dose of 2H2 18O approximately 64 h before the race to calculate total energy expenditure (TEE) and water turnover with the doubly labeled water (DLW) technique. Body weight, blood sodium and hematocrit, and muscle glycogen (via muscle biopsy) were analyzed pre- and postrace.
The TEE from DLW and indirect calorimetry was similar: 37.3 MJ (8,926 kcal) and 37.8 MJ (9,029 kcal), respectively. Total body water turnover was 16.6 L, and body weight decreased 5.9 kg. Hematocrit increased from 46 to 51% PCV. Muscle glycogen decreased from 152 to 48 mmoL/kg wet weight pre- to postrace.
These data demonstrate the unique physiological demands of the Ironman World Championship and should be considered by athletes and coaches to prepare sufficient nutritional and hydration plans.
Linda C. Hilgenbrinck
Lael Gershgoren, Edson Medeiros Filho, Gershon Tenenbaum and Robert J. Schinke
This study was aimed at capturing the components comprising shared mental models (SMM) and the training methods used to address SMM in one athletic program context. To meet this aim, two soccer coaches from the same collegiate program were interviewed and observed extensively during practices and games throughout the 2009–2010 season. In addition, documents (e.g., players’ positioning on free kicks sheet) from the soccer program were reviewed. The data were analyzed inductively through a thematic analysis to develop models that operationalize SMM through its components, and training. Game intelligence and game philosophy were the two main operational themes defining SMM. Moreover, four themes emerged for SMM training: (a) the setting, (b) compensatory communication, (c) reinforcement, and (d) instruction. SMM was embedded within a more comprehensive conceptual framework of team chemistry, including emotional, social, and cognitive dimensions. Implications of these conceptual frameworks are considered for sport psychologists and coaches.
Robert J. Gregor and Marilyn Pink
As part of an ongoing project to evaluate elite track and field throwers in the United States, the javelin competition was filmed during the 1983 Pepsi Invitational Track Meet. A high-speed video camera (Spin Physics SP2000) was positioned orthogonal to the javelin runway to record the release of all throws. During this competition, Tom Petranoff’s world record (99.72 m) was filmed at 200 fields per second. Subsequent frame-by-frame digitization yielded results consistent with reports in the literature. Release velocity was 32.3 m/s and represents one of the highest values ever reported. Angle of release was .57r, javelin attitude at release was .64r» and angle of attack was .07r. While optimum values for these release parameters, in light of published results, remain open to discussion, the results presented here represent unique information on a world record performance and can serve as a basis of comparison for future performances.
Laura A. Garvican, David T. Martin, Sally A. Clark, Walter F. Schmidt and Christopher J. Gore
Trevor L. Gillum, Charles L. Dumke and Brent C. Ruby
To describe the degrees of muscle-glycogen depletion and resynthesis in response to a half Ironman triathlon.
One male subject (38 years of age) completed the Grand Columbian half Ironman triathlon (1.9-km swim, 90-km bike, 21.1-km run, Coulee City, Wash). Three muscle biopsies were obtained from his right vastus lateralis (prerace, immediately postrace, and 4 hours postrace). Prerace and postrace body weight were recorded, in addition to macronutrient consumption before, during, and after the race. Energy expenditure and whole-body substrate oxidation were estimated from linear regression established from laboratory trials (watts and run pace relative to VO2 and VCO2).
Body weight decreased 3.8 kg from prerace to postrace. Estimated CHO energy expenditure was 10,003 kJ for the bike segment and 5759 kJ for the run segment of the race. The athlete consumed 308 g of exogenous CHO (liquid and gel; 1.21 g CHO/min) during the race. Muscle glycogen decreased from 227.1 prerace to 38.6 mmol · kg wet weight−1 · h−1 postrace. During the 4 hours postrace, the athlete consumed a mixed diet (471 g CHO, 15 g fat, 64 g protein), which included liquid CHO sources and a meal. The calculated rate of muscle-glycogen resynthesis was 4.1 mmol · kg wet weight−1 · h−1.
Completing a half Ironman triathlon depends on a high rate of muscle glycogenolysis, which demonstrates the importance of exogenous carbohydrate intake during the race. In addition, rates of muscle-glycogen resynthesis might be dampened by the eccentric damage resulting from the run portion of the race.
Henry C. Lukaski, William W. Bolonchuk, Leslie M. Klevay, David B. Milne and Harold H. Sandstead
In a pilot study, performance measures and mineral metabolism were assessed in 3 male endurance cyclists who consumed isoenergetic, isonitrogenous diets for 28-day periods in a randomized, crossover design in which dietary carbohydrate, polyunsaturated, or saturated fat contributed about 50% of daily energy intake. Peak aerobic capacity [62 ml/(kg · min)] was unaffected by diet. Endurance capacity at 70–75% peak aerobic capacity decreased with the polyunsaturated fat diet. Copper retention tended to be positive only with saturated fat. Less iron and zinc were retained (intake – losses), and fecal losses of these minerals increased with the polyunsaturated fat. Blood biochemical measures of trace element nutritional status were unaffected by diet, except serum ferritin, which tended to decrease during consumption of the polyunsaturated fat diet. These preliminary results suggest that diets high in polyunsaturated fat, particularly linoleic acid, impair absorption and utilization of iron and zinc, and possibly magnesium, and may reduce endurance performance.