Any lifter, athlete or amateur gym goer knows that getting that protein shaker bottle clean is harder than it looks—particularly if you’re drinking a shake on the go and forget to clean it right away.

Not only does it look gross when you don’t clean your protein shaker bottle after using it, you are creating the perfect environment for bacteria to grow, says “Fit Doc” IFBB Figure Pro, Cedrina L. Calder, M.DOpens a New Window.. “Bacteria can thrive in the warm, moist, and dark environment of a protein shaker bottle,” says Dr. Calder. “Combine that with the availability of protein to feed off of, and it becomes a huge germ party.”

Calder adds, “To top it off, those bacteria are what contribute to the rancid odor you smell when you open a dirty shaker bottle that’s been left sitting. A dirty shaker bottle allows bacteria to grow and collect, which puts you at a greater risk of getting sick if you use a bottle that hasn’t been properly cleaned.”

That’s why we rounded up fitness, health and cleaning experts for their best hacks to clean your shaker bottle. Now you’ll have no excuses as to why it’s still dirty and rank.