Hello! I m Pablo, I have 16 years, and I am from Brazil. I almost never made any kind of exercise in my life, but in the last 6 months my life made a 180 degrees turn, and now I m walking way more than I did before (as in never taking of from my couch to walking in a steady rhythm almost 10Km), and now I m even learning Karate, but my mother is really afraid of this change, saying that I maybe even die with all this physical stress in my body. I m not feeling that I m overdoing, but can this be really dangerous to me?