Feel like you got a crappy night’s sleep? Chances are, you did. That’s because as much as 10 percent of the weight of a two-year-old pillow is made up of dust mites and their feces. Dust mites feed on the dead skin cells we shed throughout the night, discourteously leaving their droppings near our sleeping faces in return. Spores complete this gross-out food cycle: Researchers from The University of Manchester in England found that more than one million fungal spores live in your average pillow, feasting on a smorgasbord of dust-mite feces.

What do you say, time to buy a new pillow? Now, all you need to know is what to look for. For starters, ask your wife or girlfriend—or both—how you sleep. You may also know the answer to this question yourself. If you sleep on your stomach, choose a soft pillow—one that will keep your neck from straining. If you sleep on your back, a medium pillow is best. If you sleep on your side, opt for a firm pillow. It’s also wise to find out what the pillow is made of, such as goose down or polyester. If you’re allergic to certain types of pillow fill, consider buying a hypoallergenic pillow.

If you regularly experience discomfort in your neck and shoulders while you’re sleeping, consider buying a special pillow to support your neck. A sleep study by the Johns Hopkins University School of Medicine in Baltimore, Maryland, found that those with chronic neck pain and cervicogenic headaches who sleep on water-based cervical pillows report a statistically significant improvement in their sleep comfort, pain levels and need for medication.

Tossing and turning all night will disrupt your sleep cycle and lead to an increased release of the muscle-eroding hormone cortisol. Don’t let an old, misshapen, flotsam-filled pillow get in the way of a good night’s sleep or your progress in the gym; take the time to find the right pillow for you.

Now that you’ve found the right pillow, be sure that you’re getting the most from your sleep. Check out the July/August issue of Maximum Fitness.