ISSN:0112-1642    

DOI:10.2165/00007256-198502060-00001

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

Summaryβ-Adrenoceptor blockers (β-blockers) are common first-choice drugs in the treatment of various cardiovascular disorders. Physical exercise performed during single-dose administration of β-blockers, however, is associated with an increased rate of perceived exertion; an effect which appears to be partly reduced with long term treatment. Although clinical doses of β-blockade may reduce heart rate by 30 to 35%, during maximal exercise cardiac output is not equally reduced. Accordingly, most studies have demonstrated increased stroke volume after β-blockade. This reduction in heart rate is typically accompanied by a decreased VO2max(5 to 15%) in both patients and healthy, trained subjects. This smaller reduction in VO2max, as compared with the decrease in cardiac output, is the result of a partly compensating increased arteriovenous O2difference. Work capacity as reflected by the ability to perform intense short term or more prolonged steady-state exercise is also impaired following β-blockade. β-Adrenoceptors can be subdivided into types β1- and β2. Blockers which are specific for either β1-receptors (β-selective blockers) or both β1- and β2receptors (non-selective blockers) differ with regard to their effect on exercise performance. Exercise performance ability, irrespective of exercise intensity and duration, is impaired to a greater extent following non-selective than β-selective blockade at equal reductions in heart rate. This response stems from a decreased energy flux through glycogenolysis during non-selective blockade treatment. Individuals receiving β-blockade medication therefore show greater adaptive response to physical conditioning during treatment with β1-selective than non-selective blockade probably because of greater training intensity with the former therapy. Neither psychomotor performance nor muscular strength and power is negatively affected by β-blockade. Nevertheless, the ability to perform athletic events requiring high levels of motor control under emotional stress but not high levels of aerobic or anaerobic energy release, is probably increased during β-blockade.

ISSN:0112-1642    

DOI:10.2165/00007256-198502060-00002

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryThe importance of the preseason physical examination and preparticipation evaluation of sports candidates is highlighted because it constitutes one of the few occasions in which the physician can actively prevent sports injuries from occurring. As exercise participation continues to increase on a world-wide basis, an understanding of the goals and objectives of such a pre-exercise evaluation are important. The need is not for a standard evaluation form, but for a consistent understanding of adjusting the evaluation to the age of the candidate, the type of sport to be engaged in and the anticipated level of competition. Essentials of any evaluation are musculoskeletal, cardiovascular and psychological examinations. Examinations should have clearly defined objectives, and factors determining the type of evaluation include: prospective athlete; contemplated exercise programme; and motivation. Different types of implementation are individual examinations, locker room technique and the station technique, each with advantages and disadvantages. A pre-exercise evaluation should always occur before any anticipated change in level of school or competition with an interval or intercurrent history and physical examinations occurring at regular intervals. It is important that examinations take place before the commencement of a sports season so previous injuries and problems can be dealt with; timing is vital. Contents of a pre-exercise physical examination should include history, a physical examination, laboratory testing and additional specific screening evaluations. Finally, assessment of the pre-exercise evaluation and injury prediction will aid physicians in preparticipation evaluations.

ISSN:0112-1642    

DOI:10.2165/00007256-198502060-00003

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryThis article reviews the available literature on the validity and reliability of the non-invasive techniques, commonly known as CO2rebreathing, for estimating cardiac output. The differing indirect methodologies are described and illustrated.A table, constructed from the available literature, comparing criterionversusestimated cardiac outputs is presented. The varying combinations of methods employed, differing measurement conditions, i.e. rest and exercise, and divergent populations are illustrated and discussed. The correlation between criterion and estimated cardiac output for these studies ranged from r = 0.09 to 0.96, with a % standard deviation of the differences of 1.5 to 176.8%.The Collier and end-tidal methods, in conjunction with either the Comroe or McHardy CO2dissociation curve appears to be the most established, valid and reliable combination of methods for estimating resting cardiac output. These methods appear to be comparable to the combination of the Defares, end-tidal and Comroe curve methods for estimating cardiac output during exercise.Because of the potential for large errors, caution is urged when interpreting cardiac output results based on indirect estimation for individual assessment, or for subjects with certain types of pulmonary or heart diseases.

ISSN:0112-1642    

DOI:10.2165/00007256-198502060-00004

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryIliotibial band syndrome was diagnosed in 48 of 1030 runners treated for lower extremity musculoskeletal complaints. Most athletes had been running 20 to 40 miles a week for one year or longer and had significantly changed their distance, speed, terrain, surface, and/or shoes before the onset of symptoms. Symptoms often persisted for 2 to 6 months. All runners were treated conservatively with rest, stretching, reduced distance, anti-inflammatory medications, local cortisone injections and/or orthoses.

ISSN:0112-1642    

DOI:10.2165/00007256-198502060-00005

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-198502060-00006

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS