Is Taking a Painkiller Before a Workout a Good Idea?

Is it a good idea to take a painkiller before a workout?  Will it cause you harm if you do? Are there benefits to using ibuprofen or acetaminophen for example? Does it matter which one you choose?  As a physical trainer, I am asked these questions on a very regular basis, and I can see why. This is especially true when you see how many articles are written about it online with clickbait and fearmongering titles!