No abstract

1. In a previous study of the effects of methandienone (Dianabol) on men undergoing athletic training, strength and performance increased, but not significantly more when the subjects were taking the drug than when they were taking placebo. The subjects did, however, gain more weight on the drug, with increases in total body potassium and muscle dimensions. It remained an open question whether the muscles had gained normal tissue or intracellular fluid. 2. In an attempt to distinguish between these possibilities the trial has been repeated, using as subjects seven male weight-lifters in regular training, and including measurements of total body nitrogen. As before, a dose of 100 mg of methandienone/day was given alternately with the placebo in a double-blind crossover experiment. The treatment periods lasted 6 weeks and were separated by an interval of 6 weeks. Body weight, potassium and nitrogen, muscle size, and leg performance and strength increased significantly during training on the drug, but not during the placebo period. 3. The finding of increased body nitrogen suggested that the weight gain was not only intracellular fluid. The increases in body potassium (436 +/- SEM 41 mmol) and nitrogen (255 +/- 69 g) were too large in proportion to the weight gain (2.3 +/- 0.4 kg) for this to be attributed to gain of normal muscle or other lean tissue, and imply gain of nitrogen-rich, phosphate-poor substance. Although this action of methandienone might be described as anabolic, the weight gain produced is not normal muscle.

The cardiac frequency and consumption of oxygen during submaximal exercise, lean body mass, total body potassium, thigh muscle width and an index of thigh muscle volume have been obtained for seventy-nine healthy men and women, ages 18 to 38 yrs, who were not in athletic training but accustomed to taking some exercise. For these subjects, at any specified submaximal rate of consumption of oxygen, the cardiac frequency is negatively correlated with the indices of body muscle which are themselves inter-correlated (r > 0.89). The latter relationships provide a basis for prediction of total body potassium (coefficient of variation 6f1 %).The relationship of exercise cardiac frequency to body muscle is similar in both men and women; it provides a better description of frequency than one based on consumption of oxygen alone (coefficient of variation respectively 12% and 18%). Cardiac frequency is independently related to the level of habitual activity of the subjects. The implications of these findings are discussed.Using data for young adults not in athletic training this paper examines the relationship of the cardiac frequency during submaximal exercise to indices of body muscle and shows that the two are related when allowance is also made for the consumption of oxygen. The basis for this relationship is set out below; the implications are considered in the discussion.The cardiac frequency and the cardiac output during submaximal exercise are linearly related to the consumption of oxygen; but whereas the former relationship is known to vary between subjects, the latter is relatively constant [Bevegard, Holmgren and Jonsson, 1963; Reeves, Groves, Blout and Filley, 1961]. The linearity of the two relationships implies that for an individual subject the cardiac stroke output is relatively independent of the rate of work; this is the case for exercise in both a supine and an upright posture, though for the latter the stroke output is larger during mild exercise than it is at rest [Bevegard et al., 1963]. The stroke output is the resultant of a number of factors of which one must be the muscularity of the heart. Since the cardiac output is the product of the stroke output and the frequency, the frequency at any level of cardiac output should also be related to the amount of muscle. The present study explores this relationship in groups of subjects by measuring