Changes of rat respiratory and locomotory muscles during aerobic exercise training in continuous and interval regimens

• Published in: Biophysics (Oxford) 2012-09, Vol.57 (5), p.684-689
• Main Authors: Borzykh, A. A., Kuzmin, I. V., Mart’ianov, A. A., Borovik, A. S., Sharova, A. P., Tarasova, O. S., Vinogradova, O. L.
• Format: Article
• Language: English
• Subjects: Biological and Medical Physics; Biophysics; Complex Systems Biophysics; Exercise; Physics; Physics and Astronomy; Rodents
• ISSN: 0006-3509; 1555-6654
• DOI: 10.1134/S0006350912050053

Male Wistar rats were treadmill-trained for 8 weeks using one of the two regimens: with the constant running speed or with alternating high-speed and low-speed intervals. Both training regimens led to an increase of rat aerobic capacities and to a higher citrate synthase activity in the medial head of gastrocnemius muscle. No differences between the effects of two training regimens were observed. However, in contrast to constant-speed training the interval one resulted in myocardium hypertrophy and also in less pronounced changes in diaphragm muscle, such as slow-direction shift of myosin phenotype and reduction of muscle fiber cross-sectional area. Neither of the training regimens had an effect on corticosterone and thyroid hormones levels in rat blood, whereas the interval training resulted in a higher level of testosterone. Anabolic influence of testosterone during interval aerobic training may be favorable for heart hemodynamic capacity and force characteristics of the diaphragm.