International SportMed Journal - Volume 10, Issue 3, 2009
Volume 10, Issue 3, 2009
Source: International SportMed Journal 10, pp 101 –115 (2009)More Less
Background: Over the last 20 years, there has been much interest in the quest for the 'ideal' pre-participation screening (PPS) for competitive athletes that could effectively prevent sudden cardiac death. The main features requested for this screening would be (1) feasibility in very large populations (millions of people in each country), (2) cost-effectiveness, and (3) high diagnostic accuracy (identifying only athletes with cardiac diseases without producing false-positive or false-negative results). Areas of agreement: Two models of PPS are currently applied: the American and the Italian models. The Italian PPS guidelines include a 12-lead ECG, both at rest and after exercise (3 minute step-test), in addition to medical history and physical examination, in contrast to the American PPS guidelines. This model appears to be the best method for detecting cardiovascular conditions that may predispose athletes to sudden death. Areas of controversy: Controversy exists concerning the possibility of further increase the efficacy of the screening by using echocardiography. Growing points: Based on the available evidence, echocardiographic evaluation at the beginning of the competitive activity would allow for the early identification of many congenital cardiac defects otherwise undetectable, and should be included in the European screening protocol. Timely areas for developing research: Well-constructed long-term longitudinal studies will allow ascertainment of the effectiveness of the pre-participation screening programmes. On the basis of the available evidence, the screening should probably be applied to the population at large to be effective.
Gastrointestinal (GIT) symptoms in athletes : a review of risk factors associated with the development of GIT symptoms during exercise : review articleSource: International SportMed Journal 10, pp 116 –123 (2009)More Less
Gastrointestinal tract (GIT) symptoms commonly affect endurance athletes. Although a number of risk factors for the development of GIT symptoms during exercise have been proposed, scientific evidence in support of these factors is limited. In this review article, the risk factors associated with the development of GIT symptoms during exercise will be critically reviewed.
An extensive literature review was conducted using an evidence-based approach. Using selective keywords (gastrointestinal tract symptoms, exercise, risk factors, athletes, triathletes) a search was undertaken using the PubMed database to identify all research publications that relate to the development of GIT symptoms during exercise.
There is strong evidence from a limited number of studies to support significant dehydration (body weight loss >4% during or after exercise) as a risk factor for GIT symptoms during exercise. However, more research studies are still needed to support this finding. There is some, but limited scientific evidence, to support the following as risk factors for GIT symptoms during exercise: female gender, younger age, high intensity exercise, vertical impact sport and medication use. Poor conditioning, dietary factors and previous abdominal surgery are risk factors for GIT symptoms that are not well supported and evidence is considered weak in these areas.
Therefore, further research studies of greater power, such as case control and prospective cohort studies are needed in order to evaluate risk factors adequately. Subject selection needs to be random and subjects should not be self-selected. Data needs to be collected in an objective manner not relying on subject recall. Measurement parameters also need to be standardised. In conclusion, there is very little evidence-based research to support the majority of the currently suggested risk factors for GIT symptoms in endurance athletes and further research is essential.
The International Olympic Committee (IOC) Consensus Statement on periodic health evaluation of elite athletes March 2009 : consensus statementSource: International SportMed Journal 10, pp 124 –144 (2009)More Less
In March 2009, the IOC assembled an expert group to discuss the current state of health evaluations for athletes, aiming to provide recommendations for a practical PHE for the elite athlete, as well as to outline the need for further research. The task of the group was to review the benefits as well as potential negative effects of PHE at the elite sport level. The group did not take any position as to whether PHE should be recommended as compulsory for participation in sport. That is for the relevant sports authorities to decide.
Source: International SportMed Journal 10, pp 145 –151 (2009)More Less
The present study attempts to describe the physiological demands of judo combat with the recent changes in the rules. A group of 11 subjects (elite judokas) (19.73 ± 3.13 years, 68.69 ± 15.28kg, 168.8 ± 10.50cm, and 11.09 ± 3.08 years of experience practicing the sport at the national and / or international level) were selected. The study was carried out in a simulated competition. Before competition, percentage body fat, heart rate (HR) (Suunto telemetric monitor) and lactate concentration were evaluated. Each athlete took part in an average of 2-3 matches with an official duration of 5 minutes, with a total of 16 matches. All matches were recorded with a digital video camera, HR was recorded at real time and lactate concentration was evaluated 1 and 3 minutes after the each combat. Results show match duration of between 375.06 ± 30.39 seconds, with a better total work time versus total rest time. Average HR during combat was 180 ± 8.4 beats·min-1 and reached a maximum of 188.6 ± 6.9 beats·min-1. Further, lactate concentrations demonstrate a statistically significant increase from the basal level to the level after the match (p<0.05), reaching values of up to 8.4 ± 1.2mmol·L-1. No statistically significant differences in HR and lactate concentration were found during combat. Conclusions : The changes to the rules affect the temporal structure of combat. The number and duration of pauses decreased and the duration of work sequences increased. This study reports the high physiological requirements in judo combat.
Measurement error of rearfoot kinematics during running between a 100Hz and 30Hz camera : original research articleSource: International SportMed Journal 10, pp 152 –162 (2009)More Less
Background: Measurement accuracy is critical for biomechanical gait assessment. Very few studies have determined the accuracy of common clinical rearfoot variables between cameras with different collection frequencies. Research question: What is the measurement error for common rearfoot gait parameters when using a standard 30Hz digital camera compared to 100Hz camera? Type of study: Descriptive. Methods: 100 footfalls were recorded from 10 subjects (10 footfalls per subject) running on a treadmill at 2.68m/s. A high-speed digital timer, accurate within 1ms served as an external reference. Markers were placed along the vertical axis of the heel counter and the long axis of the shank. 2D coordinates for the four markers were determined from heel strike to heel lift. Variables of interest included time of heel strike (THS), time of heel lift (THL), time to maximum eversion (TMax), and maximum rearfoot eversion angle (EvMax). Results: THS difference was 29.77ms (±8.77), THL difference was 35.64ms (±6.85), and TMax difference was 16.50ms (±2.54). These temporal values represent a difference equal to 11.9%, 14.3%, and 6.6% of the stance phase of running gait, respectively. EvMax difference was 1.02 degrees (±0.46). Conclusions: A 30Hz camera is accurate, compared to a high-frequency camera, in determining TMax and EvMax during a clinical gait analysis. However, relatively large differences, in excess of 12% of the stance phase of gait, for THS and THL variables were measured.