It has long been known that protein is essential for peak physical performance. In Ancient Greece, athletes were advised to consume large amounts of meat and wine; some even drank “beef juice.” In the 1950s, the first egg-based protein powders appeared on the market. Today, the protein supplement industry has exploded, and it is not just attracting bodybuilders.

When my lacrosse coach handed each of my teammates a shaker bottle and told us that protein drinks after our lifts were mandatory, I was skeptical. I didn’t want to bulk up, and I didn’t like the idea that my coach was regulating my diet. Moreover, no one I asked seemed to know how effective they were, what the best types of products were or how they affected the body. I decided to do some research before I agreed to put this mysterious substance into my body.

There are three common forms of protein: whey, soy and casein. First isolated in 1992, whey is a water-soluble milk protein that contains all nine essential amino acids, making it the most popular protein product. Whey is derived by processing milk into cheese and has the fastest rate of digestion, and therefore should be used shortly before or after intense workouts. Casein protein, also derived from milk, contains high levels of glutamine, an important amino acid in muscle tissue. It is harder to digest, however, so it is usually consumed before going to bed. Soy doesn’t absorb well in water and has a more unpleasant taste, but it is the best option for vegans.

Despite popular belief (to which I myself ascribed), protein powder doesn’t make you bulkier. The idea behind protein shakes is that the extra amino acids will help repair muscles damaged after intense workouts like weight lifting. The results, however, seem to be inconclusive. The International Journal of Sport Nutrition and Exercise Metabolism has published several articles that conclude that supplementing whey protein leads to increased body mass and overall strength. It has also published several contradicting articles that found little or no benefit. Even the experts remain baffled.

There is one thing that experts seem to agree on — protein supplementing can’t hurt. No studies have found any negative side effects, excluding the occasional allergic reaction to milk protein. Even the inconclusive research suggests that protein powder can be helpful in specific situations. According to Barbara Lewin, a dietician and sports nutritionist who has worked with NFL, NBA and NHL athletes, protein supplements will be most beneficial to athletes who are starting a new workout, amping up a workout — such as training for a marathon or, in my case, preparing for lacrosse season — or recovering from an injury.

At the start of the year, I could barely bench the bar. Now I can double that weight. Maybe protein powder has played a role, or maybe it hasn’t. Either way, I’ve become fondly attached to carrying around my shaker bottle and have learned to make some delicious combinations of flavors (like half chocolate, half strawberry, with a little Stevie vanilla frozen yogurt thrown in). I’m still not fully convinced of the benefits, but I’ve definitely joined the protein craze.