It is a scientifically proven fact that regular exercise improves your immune system, stimulates the formation of new brain cells, reduces the likelihood of depression, conditions your heart and circulatory system, and endows you with general strength and stamina. Recently scientific journals have even discussed the possibility that regular exercise may slow down the progression of aging and prevalence to cancer, by altering levels of certain hormones, including sex hormones, and growth factors which can feed tumors and infections.