Figure 1. Exercise improves heart function and reduces myocardial fibrosis.

(a) Rats were subjected to sham operation (C) or myocardial infarction (MI). The MI rats were trained without or with intermittent aerobic exercise (IAE) or mechanical vibration training (MVT) for 4 weeks when heart hemodynamics were measured. LVSP, left ventricular systolic pressure; LVEDP, left ventricular end-diastolic pressure; ±dP/dt, maximum pressure increasing/decreasing rate. (b) Masson staining of heart tissue section for fibrosis evaluation. Collagen is stained blue, indicating fibrosis. The lower image is an amplification of the upper black box. (c) Quantification of collagen volume of fraction (CVF). Data are mean + SE (n = 6); *p < 0.05; **p < 0.01.