I'm a competitive swimmer aiming for the 2016 Rio Olympics. What are some medication/supplements to enhance endurance and testosterone? I train 10x/wk

Natural supplements. are the best way to attempt boosting your testosterone. Medications have side effects and are illegal for the Olympics! Zinc supplementation has been shown to be of some benefit in optimizing testosterone levels Vitamin D and whey protein may also be of some benefit. The most important thing to do is train and eat right. Best of luck! :)