The areas under the 6 time-force curves were added to obtain force-time integral of the experiment. Differences of concentrations of ATP, phosphocreatine and lactate between experimental and contralateral (resting) muscles were used to calculate high-energy phosphate consumption due to stimulation. Muscle mass and cross-sectional area increased (approximately +400% and +300%, respectively) over the rat body mass range studied. Muscle length and length of the most distal fibre bundle increased by approximately 17 mm and 4 mm, respectively. Force-time integral (N.s) increased proportional to cross-sectional area whereas high-energy phosphate consumption (mumoles) increased proportional to muscle mass. The relative fraction of the total energy consumption utilized for force-independent processes was independent of rat body mass. The economy of the actomyosin system was unaffected during growth, whereas economy of the whole muscle decreased during growth by approximately 30% (p less than 0.001). The effect of muscle dimensions on economy is discussed with respect to human endurance capacity measured by voluntary isometric contractions
Meticulous research carried out by Arnold de Haan (later Professor) as part of his PhD completed under the supervision of Professor Anthony Sargeant. It might be noticed that although the experimental work in the laboratory was conducted entirely by Arnold de Haan there are eight authors on this paper. Research by committee is not always productive but it was very much the tradition in the Faculty which Tony joined in 1985. After a few years he managed to achieve a more realistic approach with only those who made a ‘significant’ contribution being listed as authors.
Influence of muscle dimensions on economy of isometric exercise in rat medial gastrocnemius muscles in situ
European Journal of applied Physiology
Eur J Appl Physiol Occup Physiol. 1988;57(1):64-9