What science says about popular pre-workout ingredients
If you don't trust the label on your pre-workout, make your own. Julia Bernhard DO YOU HAVE a big tub of pre-workout powder sitting close by? Look at the label. How many ingredients do you recognize? Protein used to be the “it factor” in fitness supplements. But these products, sometimes called “pre-workouts,” have tweaked their recipes in the past decade. “One new trend is the increasing caffeine content,” says Andrew Jagim, director of sports medicine research at Mayo Clinic Health System in Wisconsin. In 2019, he and two other experts analyzed the chemical contents of 100 widely available pre-workout powders, vitamin supplements, and drinks to understand how consuming them might affect the average exercising adult. While the breakdown hasn’t changed much in the past four years, Jagim thinks some labels are more...