摘要:

To evaluate the hypothesis that the accumulation of metabolites during training will specifically induce the adaptive synthesis of structural and enzyme proteins, the relationships between the performed exercises and the changes in muscle fibers are discussed. According to the principle of specificity of adaptation to various kinds of muscular activity, various adaptive changes are induced in muscle fiber by different types of exercise. The two main directions of training influences are action on myofibrils, induced by high resistance exercises, and action on mitochondria, induced by endurance exercises. It seems that the effect on myofibrillar hypertrophy depends on the resistance to muscle contraction, and on the total number of contractions performed against high resistance. The effect on mitochondria depends on the total period of persisting high‐level oxidation in skeletal muscle, and on the oxidation rate during these periods. Between the two main directions of training effects is the influence of power, sprint, and anaerobic interval training. In these cases, adaptation in the muscle fiber is related, in the first instance, to the sarcoplasmic reticulum and enzymes of anaerobic metabolism. Myofibrillar hypertrophy is pronounced modestly if at all in these cases, as well as in aerobic endurance training. High resistance, power, or sprint exercises do not induce adaptations at the level of mitochondria. Training may induce two different adaptations at the level of myofibrillar adenosine triphosphatase (ATPase): elevation of the enzyme activity, making possible a rapid liberation of energy for contraction (observed in sprint, interval, or strength training), and decreased enzyme activity essential for a more economical utilization of the ATP stores (in endurance training). In muscle fibers of various types the expression of training‐induced specific changes depends on involvement of fibers during the performed exercises.

ISSN:1057-8315    

DOI:10.1080/15438629309511971

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

In order to evaluate the rates of menstrual dysfunction in female elite athletes of team games, 66 Turkish athletes of indoor sports (volleyball, basketball, and handball) and 30 volleyball players from Czechoslovakia, Belgium, and Sweden were given a questionnaire on menstrual and practice history. The overall rate of menstrual irregularity (amenorrhea plus oligomenorrhea) was found to be 30%, with the visitor athletes having a rate of 43%. The athletes who were menstruating irregularly were found to train more than their counterparts during light training and the competition season. The menstrual dysfunction group consisted of younger athletes (p≤0.05). The age of onset of training was also lower (11.67±2.27) in the irregular group (p≤0.05). Of the athletes with irregularity, 80% had started training premenarchally. No differences were found between the body mass index and the age of thelarche and pubarche of the regularly and irregularly menstruating groups.

ISSN:1057-8315    

DOI:10.1080/15438629309511972

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

When athletes present any kind of cardiac arrhythmia, it is essential to specify the underlying mechanisms and to identify the arrhythmia with the help of transesophageal computer‐aided electrostimulation. This technique also allows earlier identification of previously undetected arrhythmias, specification of the underlying electro‐physiologic cause and determination of the functional condition of both the conduction and pacemaking systems of the heart. The main mechanism of identified paroxysmal supraventricular tachycardias in an athlete is a reentry of the excitation wave (with or without the involvement of additional conduction pathways) in the atrioventricular node. Apart from this paroxysmal tachycardia in an athlete, there is also accompanying dysfunction of the generation and conduction of heart impulses. Athletes with such cardiac arrhythmias (irrespective of the type of athletic activity they engage in) should be constantly followed (with periodic electrofunctional examinations) to monitor any pathologic changes developing, and their possible correction, and to make a timely expert medical decision regarding continued participation in training and competition. As far as children or young adult athletes with only a short sports career are concerned, stricter decisions should be made in view of their continuing growth and development and a possible further aggravation of cardiac abnormalities and other disorders.

ISSN:1057-8315    

DOI:10.1080/15438629309511973

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

This article presents a family systems concept of cardiac rehabilitation and reviews relevant marital and family studies in each of the following areas of cardiac risk factor modification: smoking cessation, obesity and weight reduction, behavioral control of hypertension, type A behavior pattern, and adherence. Noncardiac population research has been found to support the notion that marital and family factors may materially affect each of the health areas reviewed. However, the specific cardiac rehabilitation literature lacks well‐controlled experimental investigation of the interplay between family factors and the conventional effort to modify cardiac risk factors. The methodologic shortcomings of the existing literature in this field are discussed. General clinical recommendations are presented regarding ways to deliver cardiac rehabilitation care from a family systems perspective.

ISSN:1057-8315    

DOI:10.1080/15438629309511974

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

Rodents trained by swimming were found to develop mild myocardial hypertrophy associated with increased production of cardioprotective prostanoids and intensification of linoleic acid metabolism in cardiac phospholipids. Rats with pathologic heart hypertrophy related to hereditary hypertension displayed a reduction in the production and secretion of cardiac prostanoids, which is explained by inhibited metabolism of a number of polyunsaturated fatty acids (PUFA) in cardiac phospholipids. On the basis of the findings obtained, the authors propose techniques to prevent heart overexertion during physical loads by optimizing the exercise pattern and combining an optimal training regimen with a diet enriched by linoleic acid to increase the generation of cardioprotective prostanoids.

ISSN:1057-8315    

DOI:10.1080/15438629309511975

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629309511976

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629309511970

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor