Journal of science and medicine in sport
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We undertook a cross-sectional survey of surfers at eight Victorian beaches between February and May 2003 and analysed acute injury and chronic disability sustained while surfing during the preceding 12 months. Significant injuries were defined as requiring medical attention or time off surfing/work. 646 surfers were enrolled (90.2% male, median age 27 years, median years of surfing 10). 145 surfers sustained 168 significant acute injuries in the preceding 12 months (0.26 injuries/surfer/year, 95% CI 0.22-0.30). Most were caused by striking a surfboard or another surfer (45.2%, 95% CI 37.6-53.1), "wiping out" (36.3%, 95% CI 29.1-44.1) or striking the seabed (17.9%, 95% CI 12.6-24.7). ⋯ Significant injury while surfing is not uncommon. Although head injury accounts for a considerable proportion, very few surfers wear protective headgear. Greater use of protective headgear should be considered.
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Comparative Study Clinical Trial
Comparison of W(peak), VO2(peak) and the ventilation threshold from two different incremental exercise tests: relationship to endurance performance.
This report presents data comparing the peak rate of oxygen consumption (VO2(peak)), peak power output (W(peak)) and the ventilation threshold (VT) obtained from two different incremental cycle exercise tests performed by nine well trained triathletes (Mean +/- SD age 32 +/- 3 yrs; body mass 77.4 +/- 4.9 kg and height 185 +/- 3 cm). Furthermore, the relationship between these variables and the average sustained power output (W) during a 90 min cycle time trial (TT) was also determined. The two incremental exercise tests involved a 'short' test, which commenced at 150 W with 30 W increments every 60 s until exhaustion. ⋯ The cycle TT performance was most correlated to the W(peak) (W) (r = 0.94; p < 0.01) and the VT (W) (r = 0.75; p < 0.05) from the long test as well as the VO2(peak) (l x min(-1)) obtained from the short incremental test (r = 0.75; p < 0.01). These data suggest that the length of stages during incremental cycle exercise may influence the W(peak) and in turn the relationship of this variable to VO2(peak). Furthermore, the W(peak) obtained from a test incorporating 3 min stage increments represents the best indicator of 90 min cycle performance in well-trained triathletes.
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Clinical Trial Controlled Clinical Trial
Recognition of left ventricular hypertrophy in new recruits of professional sumo wrestling.
The efficacy of electrocardiography (ECG) in the diagnosis of left ventricular (LV) hypertrophy in 890 males, newly recruited to Japanese professional sumo wrestling (15.9 +/- 1.8 years of age, 177.8 +/- 4.7cm, 107.3 +/- 4.7kg), was tested by comparing simple, widely employed ECG criteria (Sokolow-Lyon chest and limb lead voltages and Cornell voltage with repolarisation criteria) with echocardiographic evaluations of LV mass indexed to body surface area. LV hypertrophy was defined as a LV mass index > 2 SD above the mean value obtained from 115 age-matched, normotensive, sedentary, male controls. The prevalence of LV hypertrophy as determined by echocardiography was 9.0% the entire group and was 8.3% among the 484 normotensives. ⋯ In contrast to the Sokolow-Lyon chest lead criteria, the diagnostic performance of the Cornell criteria was little affected by body mass index (BMI), and stepwise regression revealed that BMI did not significantly correlate with Cornell voltage. Still, the diagnostic efficacy of ECG was not sufficient to merit its use for primary recognition of LV hypertrophy among professional sumo wrestlers. Indeed, LV hypertrophy will likely go undetected by ECG in most overweight muscular athletes.
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Randomized Controlled Trial Clinical Trial
Effect of an acute beta-adrenergic blockade on the blood glucose response during lactate minimum test.
The aim of this study was to determine the relationship between blood lactate and glucose during an incremental test after exercise induced lactic acidosis, under normal and acute beta-adrenergic blockade. Eight fit males (cyclists or triathletes) performed a protocol to determine the intensity corresponding to the individual equilibrium point between lactate entry and removal from the blood (incremental test after exercise induced lactic acidosis), determined from the blood lactate (Lacmin) and glucose (Glucmin) response. This protocol was performed twice in a double-blind randomized order by ingesting either propranolol (80 mg) or a placebo (dextrose), 120 min prior to the test. ⋯ The exercise intensity at Lacmin was lowered (p < 0.05) from 212.1 +/- 17.4 to 181.0 +/- 15.6 W and heart rate at Lacmin was reduced (p < 0 .01) from 161.2 +/- 8.4 to 129.3 +/- 6.2 beats min(-1) as a result of the blockade. It was not possible to determine the exercise intensity corresponding to Glucmin with beta-adrenergic blockade, since the blood glucose concentration presented a continuous decrease during the incremental test. We concluded that the similar pattern response of blood lactate and glucose during an incremental test after exercise induced lactic acidosis, is not present during beta-adrenergic blockade suggesting that, at least in part, this behavior depends upon adrenergic stimulation.