Abstract
The distal tendons of the tibialis posterior, percnei longus, traius and quartus muscles from fifteen rabbits trained in a running machine were investigated regarding tensile strength properties and compared with the tendons of thirteen control rabbits of the same stock. The maximum and the linear load values were found to be higher in the trained animals. The contents of the peroneu, brevis tendons of these animals were investigated for the weight, water and collagen content and no differences were found. It was concluded that these differences must be accounted for by qualitative and not quantitative changes in the collagenous tissue as a response to the training.