Resistance training in patients with peripheral arterial disease: Effects on myosin isoforms, fiber type distribution, and capillary supply to skeletal muscle

The purpose of this study was to investigate the effects of a progressive r esistance training program on myosin heavy chain isoform expression, fiber type, and capillarization in patients with symptomatic peripheral arterial disease. Patients were randomized to either a training group (n = 11, mean +/- SD, 70 +/- 6 years, 4 men, 7 women) or a control group (n = 9, 66 +/- 6 years, 5 men, 4 women). The training sessions were completed 3 times/week, using 2 sets of various exercises. each performed for 8-15 repetitions. Mu scle biopsies were obtained before and after 24 weeks from the medial gastr ocnemius. Following the 24-week training program, the training group had si gnificantly decreased the percentage of myosin heavy chain type IIB. The pr oportion of type IIB/AB fibers as measured by using myosin adenosine tripho sphatase histochemistry decreased significantly in the training group. Ther e were significant increases in type I and type II fiber areas, and capilla ry density also increased significantly in the training group. There were s ignificant increases in 10 repetition maximum leg press and calf press stre ngths in the trained subjects. There were no significant changes in any of the measurements in the control group. It is concluded that progressive res istance training results in significant increases in muscle strength and al ters skeletal muscle composition of subjects with peripheral arterial disea se.