Could exercises or complementary therapies prevent the occurrence of panic attacks?

Yes. We all need some down time. Yoga is an excellent way to train you mind to deal with the anxiety signals it receives. In addition, hobbies and volunteering help keep your mind occupied and feeling good about your life.
Calming exercises. Have you tried relaxation breathing? If you want to avoid medication for your panic attacks, i highly recommend the book: the relaxation response by benson. Read the entire book, then start doing the exercises as contained in the book. Start with 5 minutes twice a day working up to 10 minutes twice a day. Your panic should resolve. You will be able to stop an attack with the book's techniques.