Polarized light microscopy of Toluidine Blue-stained sections. a, b- correspond to control sedentary; c, d- H. aphrodisiaca sedentary; e, f- control trained; and g, h- H. aphrodisiaca trained. The left column corresponds to the compression region and right column corresponds to the tension region. Observe a higher organization of the collagen bundles in tendons of trained (e-h) versus sedentary (a-d) animals. However, the most intense birefringence was found in tendons of trained rats and also those treated with the plant infusion (g, h). The stronger birefringence is due to the increased aggregation and longitudinal organization of the collagen bundles. Scale bar = 30 μm.