ISSN:0112-1642    

出版商:ADIS    

年代:1985

数据来源: ADIS

摘要:

SummaryPerformance in marathon running is influenced by a variety of factors, most of which are of a physiological nature. Accordingly, the marathon runner must rely to a large extent on a high aerobic capacity. But great variations in maximal oxygen uptake V̇O2 maxhave been observed among runners with a similar performance capacity, indicating complementary factors are of importance for performance. The oxygen cost of running or the running economy (expressed, e.g. as V̇O2 15at 15 km/h) as well as the fractional utilisation of V̇O2 maxmax at marathon race pace %V̇O2 ma× V̇O2 ma−1) [where Ma = mean marathon velocity] are additional factors which are known to affect the performance capacity. Together V̇O2 max, V̇O2 15and %V̇O2 ma× V̇O2 ma−1can almost entirely explain the variation in marathon performance. To a similar degree, these variables have also been found to explain the variations in the ‘anaerobic threshold’. This factor, which is closely related to the metabolic response to increasing exercise intensities, is the single variable that has the highest predictive power for marathon performance. But a major limiting factor to marathon performance is probably the choice of fuels for the exercising muscles, which factor is related to the %V̇O2 ma× V̇O2 ma−1. Present indications are that marathon runners, compared with normal individuals, have a higher turnover rate in fat metabolism at given high exercise intensities expressed both in absolute (m/sec) and relative %V̇O2 maxterms. The selection of fat for oxidation by the muscles is important since the stores of the most efficient fuel, the carbohydrates, are limited. The large amount of endurance training done by marathon runners is probably responsible for similar metabolic adaptations, which contribute to a delayed onset of fatigue and raise the %V̇O2 ma× V̇O2 ma−1. There is probably an upper limit in training kilometrage above which there are no improvements in the fractional utilisation of V̇O2 maxat the marathon race pace. The influence of training on V̇O2 maxand, to some extent, on the running economy appears, however, to be limited by genetic factors.

ISSN:0112-1642    

DOI:10.2165/00007256-198502020-00002

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryStandard exercise testing and training methods require leg work, but alternative methods involving arm work appear to be particularly applicable for selected subjects. An understanding of the physiology of upper extremity exercise and of the implications for arm exercise testing and training will assist in the diagnostic and functional evaluation and prescription of exercise.The cardiorespiratory and haemodynamic responses to submaximal and maximal arm and leg exercise are reviewed and practical information and guidelines for the recommendation of arm exercise testing and training in wheelchair-confined individuals, normal subjects, and patients with coronary heart disease are provided.

ISSN:0112-1642    

DOI:10.2165/00007256-198502020-00003

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryThe development of muscular fatigue during exercise is a common phenomenon, and several forms depend on the precise type of exercise performed. The causes are still not clearly established, although the involvement of electrical and metabolic factors have been demonstrated. Several techniques which allow for the analysis of muscle function in terms of electrical activation and energy metabolism are (a) a needle biopsy of muscle for histo-chemical and metabolic studies, (b) magnetic resonance spectroscopy for the non-invasive study of muscle energy metabolism and pH, (c) electromyographic analysis of the electrical characteristics of muscle, and (d) percutaneous electrical stimulation of muscle for the force-frequency and relaxation characteristics of muscle. Endurance training increases the capacity to sustain exercise possibly by altering muscle energy metabolism and contractile properties.Fatigue is a self-protective mechanism against the damage of contractile machinery of muscle as, for example, with the development of rigor, which occurs if the energy stores are depleted. To illustrate the roles of energy supply and electrical properties in muscle in fatigue, the ’catastrophe theory’ used in engineering has been applied. This may explain abrupt changes of function of individual muscle cells, while for the muscle as a whole, fatigue may be manifested as a more gradual loss of force.

ISSN:0112-1642    

DOI:10.2165/00007256-198502020-00004

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-198502020-00005

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

摘要:

SummaryUnderstanding the biomechanics of running has brought implications for the prevention of foot injuries. These biomechanical considerations, both functional and non-functional, must be evaluated by the sports medicine practitioner. Although functional biomechanical findings are clinically more accurate predictors of injury and diagnostic tools than static findings, a correlation between the two is essential. Other important variables, e.g. training methods, athletic shoes, psychology, general health, external environment (surfaces, weather) and overuse, must be correlated with the biomechanical findings.The methodology and results of research are inconsistent with the direct predictability of various overuse injuries, based on biomechanical abnormalities and/or contributing factors. Until more research is carried out, clinical experience and the results of structured research investigations will provide the basis of treatment.

ISSN:0112-1642    

DOI:10.2165/00007256-198502020-00006

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS

ISSN:0112-1642    

DOI:10.2165/00007256-198502020-00007

出版商:Springer International Publishing    

年代:2012

数据来源: ADIS