You can't escape it: You’re getting older. In fact, age-related hormonal decline can begin as early as age 25, and accelerate dramatically in your 30s and beyond. After 30, studies show, male testosterone drops 2–3% per year, and growth hormone production plummets 14% per decade—both of which can promote weight gain, leave you feeling sluggish and weak, and do a number on your sex drive.

But, good news: There are factors you can control so aging doesn’t have to mean getting paunchy, wheezing up stairs, or avoiding the bedroom. Boosting hormone levels is easier—and more effective—than you’d think.

With this step-by-step primer, you can stimulate your testosterone and human growth hormone.