Running can increase bone mass density, especially in the hips and the legs of which are prime osteoporosis targets on our bodies. Professional runners have a higher than normal density, study that was held at Erlangen University in Germany showed the average professional measured density was 1,246mg per sq cm, were as non runners held an average of 1,138mg per sq cm.
Just over a 100 mg increase which is a high gain overall. Running is a great sport to start up and can give the body many gains for the future.