ISSN:0112-1642    

DOI:10.2165/00007256-199519030-00001

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-199519030-00002

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryWhen a gas mixture containing carbon dioxide (CO2) is inhaled by an individual, alveolar ventilation is increased. This ventilatory response to CO2highlights the relationship between the increase in exercise ventilation and the increase in alveolar CO2pressure (paCO2). This response is mediated centrally by brainstem chemoreceptors in the medulla and, to a lesser extent, peripherally by the carotid and aortic bodies. However, the response of increased breathing to rising paCO2varies markedly among individuals.The responses to CO2rebreathing have been investigated by a variety of research groups for different reasons. The range of responses by children and adults including: gender differences; responses by athletes; the relationship between age and body size; and whether it is an acquired or inherited response have been studied.The following is a summary of these different aspects of CO2rebreathing has been complied to assist researchers studying any single or multiple facets of the area.

ISSN:0112-1642    

DOI:10.2165/00007256-199519030-00003

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryToday’s elite hockey players are physically bigger and have improved levels of physiological fitness when compared with their predecessors. Correspondingly, previous ice hockey studies that have become widely referenced may have little relevance to current players and the way the game is presently played.A great need exists to apply exercise science to the game of ice hockey. Although much has been written about the physiology of ice hockey, there is little information based on well controlled studies. Particularly, there is a paucity of knowledge concerning optimal training schedules, training specificity, recovery profiles and seasonal detraining. Moreover, the reports that do exist have attempted to make comparisons across all levels of skill and talent. Thus, fundamental questions remain as to actual physiological exercise response and specialised training programmes for ice hockey players, particularly at the elite level.There is a demand for new properly designed experiments to find answers pertaining to the appropriate training methods for today’s ice hockey players. Future research directions should consider the relationships between performance and such variables as neuromuscular skills, strength, power, peripheral adaptations, travel, hydration, detraining and sport-specific training programmes. Incidence and severity of injury among ice hockey players in relation to fatigue and fitness must also be investigated. Much of the information currently used in ice hockey will remain speculative and anecdotal until these studies are conducted.

ISSN:0112-1642    

DOI:10.2165/00007256-199519030-00004

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryThe development of active isokinetic dynamometers has allowed the assessment of muscular moment under eccentric activations that have different characteristics to concentric actions. It is well documented that at a given angular velocity the eccentric moment is greater than the corresponding concentric moment. The moment-velocity relationship under eccentric conditions has been investigated, with conflicting results. Particularly, eccentric moment was reported to remain similar to, or to increase or decrease with, increasing angular velocity. As with concentric actions, the reliability of isokinetic eccentric measurements is influenced by a number of factors such as gravity, preload force and testing position.The velocity-specific effects of eccentric training have not been extensively investigated. Based on current knowledge, eccentric exercise does not appear to be velocity-specific. Although the mode specificity of both concentric and eccentric exercises have been investigated, the resultant observations are conflicting. Eccentric training has been found to improve both concentric and eccentric strength; yet, it has also been reported to improve only concentricoreccentric strength. The reciprocal muscle group ratios under eccentric actions were found not to be influenced by angular velocity, but the significant role of the eccentric/concentric moment ratio of each muscle has not been examined thoroughly. It is well documented that eccentric activations are associated with delayed muscle soreness and muscle damage. A limited number of studies have reported that isokinetic eccentric efforts may result in a lower amount of muscle soreness compared with other exercise modalities.Isokinetic dynamometers provide some unique characteristics for rehabilitation applications. Examination of the clinical application of eccentric exercise is limited. Consequently, the use of this exercise modality in prevention and assessment of musculoskeletal injuries should be investigated further.

ISSN:0112-1642    

DOI:10.2165/00007256-199519030-00005

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummarySyncope is a brief sudden loss of consciousness and muscle tone secondary to cerebral ischaemia, inadequate oxygen or glucose delivery to the brain. The causes of syncope may be benign and require very little in the way of evaluation or treatment. However, syncope may be the harbinger of sudden death, and extensive evaluation, monitoring and detailed recommendations regarding advisability of participating in sports should be reviewed with the patient.The history is the most important clue when attempting to identify which patient with syncope is at risk for sudden death. A careful cardiac and neurological examination should be performed in any patient presenting with syncope. Selective use of laboratory testing and cardiac monitoring may assist the practitioner in making the diagnosis.Most often patients with syncope will have a benign cause such as vaso-vagal events, hyperventilation or orthostatic hypotension. Patients with a cardiac condition causing their syncope are at increased risk for sudden death. The ominous, cardiac-related causes of syncope in the younger population include hypertrophic cardiomyopathy, aberrant coronary arteries and aortic dissection secondary to Marfan’s syndrome. In the older athletic population, coronary atherosclerosis may present with syncope. Dysrhythmias may be the cause of syncope in both populations.

ISSN:0112-1642    

DOI:10.2165/00007256-199519030-00006

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS