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- Volume 18, Issue 2, 2006
South African Journal of Sports Medicine - Volume 18, Issue 2, 2006
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Volume 18, Issue 2, 2006
Author Mike LambertSource: South African Journal of Sports Medicine 18 (2006)More Less
Extracted from text ... Every couple of months an incident in the sporting world triggers a passionate public debate. Members of the public are quick to form and express their opinion. Often the area of discussion is beyond the scope of expertise of the person contributing to the debate; however this does not deter them from doing so with gusto. The media often get involved in these debates and seek out anyone who will give them a dial-a-quote on the incident. The most recent example which springs to mind is the discussion about `Wayne Rooney's metatarsal?. Soon after his injury everyone from the managing ..
Influence of menstrual phase on ventilatory responses to submaximal exercise : original research articleSource: South African Journal of Sports Medicine 18, pp 31 –37 (2006)More Less
<i>Objectives.</i> To determine whether an increase in respiratory drive, due to elevated progesterone and oestrogen concentration during various menstrual phases, persists throughout prolonged submaximal exercise and potentially contributes to fatigue. Furthermore, to determine whether the difference in the ventilatory response to exercise from one menstrual phase to another is correlated to the ovarian hormone concentrations. <br><i>Design.</i> We compared the change in ventilatory parameters during 90 min exercise at 60%VO<sub>2max</sub> between the early follicular (EF) and mid-luteal (ML) phase (N = 9) and between the EF and late follicular (LF) phase (N = 5) in eumenorrhoeic women. <br><i>Main outcome measures.</i> Menstrual phase comparisons and correlations between the change in ventilatory parameters (minute ventilation (V<sub>E</sub>), respiratory rate (RR), tidal volume) from the EF to ML or from the EF to LF phase and ovarian hormone concentration. <br><i>Results.</i> The difference in RR between EF and ML phases correlated to progesterone concentration in the ML phase (r = 0.7, p = 0.04). In addition, RR was higher during exercise in the ML compared with EF phase for the full duration of exercise by on average 2.3 ± 2.1 breaths/min (p < 0.05). However, no difference in submaximal VO<sub>2</sub> between menstrual phases was evident. No significant difference in exercising-V<sub>E</sub> was observed between menstrual phases, but the change in V<sub>E</sub> from EF to ML correlated to oestrogen (r = 0.8, p = 0.02) and progesterone (r = 0.7, p = 0.04) concentration in the ML phase. <br><i>Conclusions.</i> The change in ventilatory parameters from EF to ML phase is related to the ovarian hormone concentrations. Therefore inter-individual variability should be considered in menstrual phase comparative studies. Furthermore, the persistently higher RR noted during exercise in the ML phase did not increase metabolic rate, and is therefore not expected to affect rate of fatigue significantly, even during prolonged exercise.
Fitness and body composition profiling of elite junior South African rugby players : original research articleSource: South African Journal of Sports Medicine 18, pp 38 –45 (2006)More Less
<i>Objective.</i> The aim of this study was to describe the body composition, strength and speed characteristics of elite junior South African rugby players. <br><i>Design.</i> Cross-sectional. <br><i>Setting.</i> Field study. <br><i>Subjects.</i> Rugby players (16 and 18 years old, N = 174) selected for the South African Rugby Union National Green Squad. <br><i>Outcome measures.</i> Body composition, 10 m and 40 m speed, agility, 1RM bench press, underhand pull-ups, push-ups, multistage shuttle run. <br><i>Results.</i> The under-16 players were on average shorter (175.6 ± 5.7 v. 179.2 ± 6.7 cm), weighed less (76.5 ± 8.2 v. 84.8 ± 8.3 kg) had less upper body absolute strength (77.1 ± 11.8 kg v. 95.3 ± 16.7 kg) and muscular endurance (41 ± 12 v. 52 ± 15 push-ups) and aerobic fitness (87.1 ± 19.4 v. 93.5 ± 15.3 shuttles) than the under-18 players. There were no differences in body fat, sprinting speed (10 m and 40 m) or agility between the two age groups. There were differences between playing positions, with the props having the most body fat, strongest upper bodies, slowest sprinting speed, least agility and lowest aerobic capacity compared with players in the other positions. <br><i>Conclusion.</i> This study provides data for elite junior rugby players and can be used to monitor the progression of players after intervention while also assisting with talent identification for the different playing positions.
Source: South African Journal of Sports Medicine 18, pp 46 –51 (2006)More Less
The prevalence of asthma and airway hyperresponsiveness (AHR) in highly trained endurance athletes is rising. The type of training (i.e. endurance, or speed and power) seems to influence the airway symptoms. High-intensity exercise and training might contribute to the development of asthma or AHR in athletes previously unaffected by these airway disorders. Repeated hyperventilation of unconditioned air, as well as air containing irritants and/or allergens has been suggested to cause thermal, mechanical, or osmotic airway trauma resulting in damage to the airway epithelium. Subsequent airway inflammatory responses may be responsible for the development of atopy-related symptoms in endurance athletes such as those observed in asthma and AHR. Eosinophils and neutrophils are the inflammatory cells that have been frequently observed to be elevated in the airways of endurance athletes. The trafficking of these cells to the airways may possibly be regulated by T<sub>H</sub>2 cytokines that are expressed in the airways in response to epithelial cell damage. In addition, these airway inflammatory responses may lead to airway remodelling similar to that which occurs in asthma. The effect of the exercise challenge itself may initiate airway atopy-related and inflammatory responses in endurance athletes. While the literature seems to support the role of local airway conditions and/or events in inducing atopy-related symptoms in athletes, it is proposed that alterations in the hormonal and/or cytokine milieu with intense competition and/or training may also play a role.
Source: South African Journal of Sports Medicine 18, pp 52 –55 (2006)More Less
<i>Objectives.</i> The purpose of this study was to evaluate the patient presentation data for spectators attending the opening ceremony and all the 2003 Cricket World Cup matches played in South Africa in order to provide organisers with the basis of a sound medical care plan for mass gatherings of a similar nature. <br><i>Methods.</i> During the 2003 Cricket World Cup, data were collected on the spectators presenting to the medical facilities during the opening ceremony and the 42 matches played in South Africa. Data included the total number of patient presentations and the category of illness or injury. This information was used to determine the venue accommodation rate and the patient presentation rate. The illness/injury data were classified into the following categories: (i) heat-related illness; (ii) blisters/scrapes/ bruises; (iii) headache; (iv) fractures/sprains/lacerations; (v) eye injuries; (vi) abdominal pain; (vii) insect bite; (viii) allergy-related illness; (ix) cardiac disorders, chest pains; (x) pulmonary disorder/shortness of breath; (xi) syncope; (xii) weakness/dizziness; (xiii) alcohol/drug-related conditions; (xiv) seizure; (xv) cardiac arrest; (xvi) obstetric/ gynaecological disorder; and (xvii) other. <br><i>Results.</i> The total number of patients who presented to the medical stations was 2 118, with a mean of 50 (range 14 - 91) injuries per match. The mean for the patient presentation rate was 4/1 000 spectators. The most frequently encountered illness or injury was headache (954 patients, 45%), followed by fractures, sprains and lacerations (351 patients, 16%). <br><i>Conclusion.</i> The unique nature of cricket has shown a different patient presentation rate than for other similar mass gatherings, requiring additional factors be considered when developing a medical care plan.