2:00 to 10:00 p.m. which is maybe when you most need it. >> exactly. >> so then it starts declining. so you need to sleep. number two, for example, stress. in your body the pathway of testosterone production which starts with cholesterol. people don't realize that. cholesterol is not only bad but a good thing because it is one of the precursors for testosterone. >> right. you have good and bad cholesterol. >> absolutely. cholesterol becomes testosterone but another pathway is cortisol, a stress hormone. whenever you are stressed cholesterol a lot of times goes to the cortisol. so stress is one of the things can also lower your testosterone. >> draining it away. >> obesity. absolutely. obesity is kind of simple. fat cells have certain enzymes that convert testosterone to estrogen.