Thank you Xamilo for your advice. I live in Italy, we ask to
anyone who enroll to our yoga lessons to give us a doctor's declaration in which has been stated that the person is healthy. You know, , the document is called litterally "certificate of good health" (certificato di buona salute) and whoever practices any phisical activity in a public place is bound to have it. It's generic and most of the time free of charge, on the contrary, for a visit and a prescription from a cardiologist the amount to pay is at least 200$! This student has the first document, I mean she was declared healthy by a doctor, but she fefuses to have the other one...