Zitat:
Zitat von eddy87
Zitat:
Dazu kommt, dass Krafttraining selbst (auch ohne Steroidkonsum) unter Umständen scheinbar ebenfalls eine konzentrische H.-Hypertrophie auslösen kann (ob das tatsächlich gesundheitsschädlich ist, kann Dir m.E. auch niemand mit letzter Sicherheit sagen).
Das stimmt so nicht denn ein Sportlerherz ist etwas anderes als eine konzentrische Herzhypertrophie,aber danke für die Antwort.
Ich rede nicht vom "typischen" Sportherz! Ich rede von besonderen Veränderungen der "Herzarchitektur" durch Kraftsport. Es wird zumindest diskutiert, dass Kraftsport unter Umständen selbst - genau wie Steroide auch - eine konzentrische Hypertrophieform verursachen kann (wenn ich mich richtig entsinne, geht es dabei vor allem um Powerlifting, da hier die aerobe Trainingskomponete am niedrigsten und die Blutdruckspitzen am höchsten sind).
http://circ.ahajournals.org/cgi/cont...c2e084b1fe7efd
Zitat:
Top-level training is often associated with morphological changes in the heart, including increases in left ventricular chamber size, wall thickness, and mass. The increase in left ventricular mass as a result of training is called "athlete`s heart." Morganroth et al were the first to postulate that 2 different morphological forms of athlete`s heart can be distinguished: a strength-trained heart and an endurance-trained heart.
(...)
Athletes involved in mainly static or isometric exercise (eg, weightlifting) develop predominantly increased left ventricular wall thickness with unchanged left ventricular chamber size, which is caused by pressure overload accompanying the high systemic arterial pressure found in this type of exercise. Thus, strength-trained athletes are presumed to demonstrate concentric left ventricular hypertrophy, which is characterized by an increased ratio of wall thickness to radius.
(...)
However, the classification as an endurance-trained heart or a strength-trained heart is not an absolute and dichotomous concept but rather a relative concept.
http://heart.bmjjournals.com/cgi/content/full/90/5/473
Zitat:
We know, for example, that the magnitude and pattern of hypertrophy is dependent on the nature, duration, and intensity of exercise undertaken. Thus, strength trained athletes (such as weightlifters, powerlifters, bodybuilders, and throwers) develop a greater increase in wall thickness, a more concentric pattern of LV growth, and a lesser increase in LV chamber internal dimensions in comparison to those undergoing predominantly aerobic/endurance exercise.
Allerdings ist die Geschichte offenbar nicht ganz 100%ig klar. So schreiben z.B. Haykowsky et al...
Zitat:
Resistance training (RT) programmes are well known to improve muscle strength and endurance for sport. RT has also gained popularity as an effective form of exercise to improve general healthfitness. In addition, RT is accepted as a safe and effective therapeutic exercise intervention to attenuate the age-related decline in muscle mass and functional capacity. However, despite these established benefits, disagreement exists concerning the effect of RT on left ventricular (LV) morphology. Previous reviews indicate that RT increases LV internal cavity dimension, ventricular septal wall thickness, posterior wall thickness, relative wall thickness, and LV mass. A widely held belief in sport cardiology and exercise physiology is that serious RT for sport produces cardiac hypertrophy, which is usually defined as concentric hypertrophy (i.e. increased LV mass secondary to an increase in LV wall thickness with minimal alteration in internal cavity dimension). In contrast, some investigations have shown that short- (<5 years) to long-term (>18 years) RT was not associated with an alteration in LV internal cavity dimension,ventricular septal or posterior wall thickness, relative wall thickness,or LV mass in either male or female resistancetrained
athletes. (...) Taken together, these studies suggest that RT does not necessarily produce concentric hypertrophy. Disparate findings may be caused by the type of resistance-trained athletes that have been studied (i.e. bodybuilders, powerlifters, or Olympic weightlifters) or the underlying use of anabolic steroids...
Hartgens und Kuipers schreiben zum Thema AAS und Herz folgendes:
Zitat:
Eight crosssectional studies observed differences in one or more echocardiographic variables between AAS users and non-using strength athletes, whereas five studies did not register any difference.
Compared with nonusers steroid users have been demonstrated to show larger left ventricular mass and/or left ventricular index and larger posterior wall and interventricular septum thicknesses. The majority of studies seem to show that the left ventricular cavity during diastole and systole is not subject to alterations under the use of steroids.
To date, only six prospective echocardiographic studies have been published and only one study reported steroid-induced changes in echocardiographic variables.
(...)
The effects of prolonged AAS abuse and/or the use of many successive AAS courses remain unknown. Nevertheless, animal studies clearly have shown that short-term use of androgens and anabolic agents may exert strong hazardous effects on cardiac structure and function and, therefore, it has been proposed that echocardiography might be not sensitive enough to detect early and small changes due to AAS administration.
PS: Das Thema hatten wir hier schon einmal (ebenfalls mit einigen Links):
http://www.bbszene.de/board/viewtopi...092&highlight=
