Skin breakouts can plague people through many different stages in life and aren’t only the bane of teenagers. Ironically it could be your regular exercise that is raising your basal testosterone level and creating more oil gland activity. Fortunately this does not mean that you have to give up your exercise routine! There are a number of holistic options to try. I would start by giving the tetracycline antibiotics a break. The surviving bacteria will probably no longer respond to a longer course and even worse, your friendly gut flora could be in the process of being destroyed which will play havoc with your immune system. Use a tea tree oil or salicylic acid cleanser twice daily to take care of balancing your skin oil production and destroying unwanted bacteria and demodex mite. Apply a lotion containing fruity acids and avoid creams that contain vitamin E (tocopherol). Take a natural antibiotic such as wild oregano or olive leaf extracts and a high quality concentrated probiotic. Supplements containing zinc, copper and vitamin B5 will heal the gut and the skin together. If the problem persists, have your DHEA and testosterone levels checked and balanced if necessary. Wishing you a clear skin recovery!