Not ejaculating for a week is said to increase testosterone levels by about 45.7%. Although, no scientific evidence backs this sperm retention science claim, there is plenty of anecdotal evidence to suggest otherwise. Individuals have testified to an increase in testosterone levels and other mental and physical benefits of this exercise such as elevated productivity and better sleep, respectively. It may work for some, or it may not. Point is, there's no harm in not ejaculating for 7 days.