Medicine and science in sports and exercise
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Med Sci Sports Exerc · Nov 2008
Clinical TrialTo cool, but not too cool: that is the question--immersion cooling for hyperthermia.
Patient cooling time can impact upon the prognosis of heat illness. Although ice-cold-water immersion will rapidly extract heat, access to ice or cold water may be limited in hot climates. Indeed, some have concerns regarding the sudden cold-water immersion of hyperthermic individuals, whereas others believe that cutaneous vasoconstriction may reduce convective heat transfer from the core. It was hypothesized that warmer immersion temperatures, which induce less powerful vasoconstriction, may still facilitate rapid cooling in hyperthermic individuals. ⋯ It is assumed that this rapid heat loss was due to a less powerful peripheral vasoconstrictor response, with central heat being more rapidly transported to the skin surface for dissipation. Although the core-to-water thermal gradient was much smaller with temperate-water cooling, greater skin and deeper tissue blood flows would support a superior convective heat delivery. Thus, a sustained physiological mechanism (blood flow) appears to have countered a less powerful thermal gradient, resulting in clinically insignificant differences in heat extraction between the cold and temperate cooling trials.
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Med Sci Sports Exerc · Oct 2008
Comparative StudyExercise testing to estimate survival in pulmonary hypertension.
: The 6-min walk distance (6MWD) predicts survival in pulmonary hypertension (PH). The peak oxygen consumption (V O2peak) measured during a cardiopulmonary exercise test (CPET) also relates to survival in PH, and it is unknown how the prognostic information from measurements of ventilatory responses and gas exchange during CPET compares to the prognostic information obtained by the 6MWD alone. The aims of our study were to compare prognostic values of different exercise parameters in PH and to assess whether CPET adds prognostic value to the information from the 6MWD. ⋯ : CPET parameters predict survival in PH patients and add marginally to the prognostic value of the 6MWD.
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At present, the risk of myocardial damage by endurance exercise is under debate because of reports on exercise-associated increases in cardiac biomarkers troponin and B-type natriuretic peptide (BNP); these markers are typically elevated in patients with acute myocardial infarction and chronic heart failure, respectively. Exercise-associated elevations of cardiac biomarkers can be present in elite and in recreational athletes, especially after prolonged and strenuous endurance exercise bouts (e.g., marathon and ultratriathlon). ⋯ In addition, elevations in cardiac biomarkers in athletes after exercise may generate difficulties for clinicians in terms of differential diagnosis and may result in inappropriate consequences. Therefore, the aim of this article is to provide an overview of exercise-associated alterations of the cardiac biomarkers troponin T and I, ischemia-modified albumin, BNP, and its cleaved inactive fragment N-terminal pro BNP for the athlete, coach, scientist, and clinician.
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Med Sci Sports Exerc · Aug 2008
Predictive value of orthopedic evaluation and injury history at the NFL combine.
The National Football League (NFL) holds an annual combine to evaluate college football athletes likely to be drafted for physical skills, to review their medical history, and to perform a physical examination. The athletes receive an orthopedic grade on their ability to participate in the NFL. The purpose of this study was to test the hypothesis that this orthopedic rating at the combine predicts the percent of athletes who play in the NFL and the length of their careers. ⋯ This is the first study to report on the predictive value of a grading system for college athletes before participation in professional sports. Other professional sports may benefit from using a similar grading system for the evaluation of potential players.
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Med Sci Sports Exerc · Aug 2008
Randomized Controlled TrialBeta-glucan, immune function, and upper respiratory tract infections in athletes.
This study investigated the effects of oat beta-glucan (BG) supplementation on chronic resting immunity, exercise-induced changes in immune function, and self-reported upper respiratory tract infection (URTI) incidence in human endurance athletes. ⋯ An 18-d period of BG versus P ingestion did not alter chronic resting or exercise-induced changes in immune function or URTI incidence in cyclists during the 2-wk period after an intensified exercise.