Sports dietitians break down everything you need to know about common and not-so-common workout supplements—including which you should take and which you can skip.
If you've ever dipped a toe into the vast world of sports supplements, you know that there a ton to choose from. And while supplementation is absolutely a useful tool that can help you meet your nutritional, performance, and aesthetic goals, it's not always super clear which supplements are legit and which ones are a waste of time. (Like those gummy vitamins that are supposed to help your hair grow...)
"Supplements aren't regulated by the FDA, meaning there isn't required third-party testing for safety," says Amy Goodson, R.D., a board-certified specialist in sports dietetics. That means doing some research on your own ahead of time and/or going directly to a dietitian or doctor for specific brand recommendations is essential. Goodson suggests looking for supplements that have been marked as NSF Certified for Sport or Informed Choice. Still, this doesn't mean its intended effects are totally research-backed.
We asked sports nutrition experts for a full rundown on the most popular sports supplements, what they're supposed to do, and whether or not they're the real deal. Here's what they had to say.
What it's for: Muscle growth
The claim: Probably the most common workout supplement, protein powder is pretty much everywhere these days. An adequate protein intake helps build, repair, and maintain muscle, according to Ryan Maciel, R.D.N., C.S.C.S.
The evidence: "There are numerous studies showing the effectiveness and safety of using protein powders," Maciel says. Though there are many different kinds, "whey protein is the most popular because it contains the highest amount of branched-chain amino acids, specifically leucine," Goodson explains. "This is important because research supports leucine as the 'light switch' for turning on muscle resynthesis and thus promotes recovery." Of course, whey contains dairy, so if you're dairy-free, then soy, pea, egg white, rice, and hemp protein are all good options too.
Recommended dosage: "The Academy of Nutrition and Dietetics recommends 1.2 to 2.0 grams of protein per kilogram body weight for athletes," Maciel says. Most people can reach this amount of protein through diet alone, but if you're not quite making it there, protein powder might be a good option. For most women, 20 to 30 grams of protein per meal is a good place to start, according to Maciel. That's equal to about one scoop of the stuff.
And though it's normally recommended that you down a protein shake ASAP after exercise, recent research suggests that hitting your recommended protein intake over the course of the entire day is what matters most. That means you can incorporate protein powder into your day at any time to meet your protein needs for the day and still reap the benefits. (Related: The Best Protein Powders for Women, According to Nutritionists)
What it's for: Anti-aging
The claim: "Collagen is found in our bones, muscles, skin, and tendons," Maciel says. "Collagen is what holds our body together, in a sense. As we age, our collagen production slows and as result, we start to see signs of aging, like wrinkles." So it makes sense that people think supplementing with collagen could help slow down the effects of aging—and help the body's natural ability to repair joints, muscles, and tendons.
The evidence: While this is one of the most buzzed-about supplements at the moment, you probably don't want to run out and buy it just yet. "To date, there is no substantial scientific evidence that collagen supplementation can slow or reverse the effects of aging," Maciel says. "You're better off consuming a well-balanced diet made up of lean proteins, fruits, vegetables, whole grains, and healthy fats, being physically active, using sunblock, and not smoking." Goodson does note that collagen is rich in protein, so if you're looking for an added boost in smoothies, soups, or other foods, a powdered collagen supplement could be a good choice. (Related: Should You Be Adding Collagen to Your Diet?)
What it's for: Performance
The claim: "It can improve exercise capacity and performance during high-intensity exercise," Maciel says. "During high-intensity exercise, hydrogen ions accumulate in your muscles, which can cause muscle fatigue and slow you down. Beta-alanine may help alleviate this by acting as a buffer for those ions."
The evidence: It's probably legit. "Beta-alanine may be worth taking if you do high-intensity exercise, since research has shown it can improve performance," Maciel says.
Recommended dosage: Somewhere between 2 and 6 grams per day. "Consume it with a meal for better absorption," Maciel recommends. And heads-up: A common side effect is a tingling sensation. "To reduce this side effect, try taking smaller doses throughout the day or use time-release capsules," he adds.
Branched-Chain Amino Acids (BCAA)
What it's for: Performance and recovery
The claim: "Branched-chain amino acids are a source of energy in exercise and become a more substantial fuel source in endurance exercise when carbohydrates stores are low," Goodson explains. Taking them before and after a workout is supposed to enhance performance and reduce fatigue.
The evidence: "The evidence doesn't support the marketing claims from supplement manufacturers," Maciel says. "You're better off getting your BCAAs from food sources such as chicken, beef, fish, and eggs. Also, if you drink whey protein, you are getting plenty of BCAAs, so supplementation may be a waste of money."
What it's for: Performance and muscle growth
The claim: Creatine is stored in your muscles and supplies them with energy, according to Maciel. "Creatine supplementation increases your muscles creatine stores, which results in improved performance during intense physical activity, such as sprinting and strength training."
The evidence: "Creatine is one of the most researched supplements to date," Maciel notes. "It is proven to be safe and effective for improving strength, power, and lean body mass."
Recommended dosage: Five grams per day is the most typical dose, Goodson says. While some people may do a "loading phase" with a higher dose and then decrease the dosage afterward, this probably isn't necessary. "Creatine can lead to weight and muscle gain for those who take it consistently, so women looking to lose or maintain weight should take caution," she adds.
What it's for: Performance
The claim: These mixes are formulated to provide more energy for better performance during workouts.
The evidence: "Pre-workout powders and drinks are all created a little differently based on the brand, but most are a cocktail of carbohydrate, caffeine, some amino acids, creatine, and often beta-alanine, and some contain other vitamins as well," Goodson says. "These are really designed to give people energy from the caffeine and carbohydrate, and possibly provide an added performance booster from creatine. (Related: Why Caffeine Is the Best Thing That's Ever Happened to Your Workout)
Recommended dosage: Follow the product directions, with one caveat: "People who are caffeine-sensitive or who have not eaten anything should always be careful when consuming these type of products," Goodson says.
Tart Cherry Juice
What it's for: Recovery
The claim: "Tart cherry juice or cherry skin powder contains a high concentration of anthocyanins, an antioxidant, that may help you recover quicker and be less prone to illness following strenuous exercise," Maciel explains.
The evidence: Studies are limited but promising, Maciel says, but there's not much harm to be done from drinking natural fruit juice, so there's no reason not to try this to speed up recovery.
Recommended dosage: Tart cherries can be consumed in either juice or powder form. The amount that has been studied is 8 to 12 ounces twice a day for four to five days before a strenuous event, and then for two to three days afterward. "Be aware that tart cherry juice is still juice and does contain a decent amount of carbohydrates, so women looking to lose weight need to factor those calories in if using it as a post-workout or recovery beverage," Goodson says.
What it's for: Recovery, performance, and muscle growth
The claim: Glutamine is an amino acid that serves as an important fuel source for your body. "It is believed that supplementation can increase the body's supply of glutamine, which will speed up recovery, increase muscle growth, and improve performance," Maciel says.
The evidence: There's little scientific evidence to support taking glutamine for improving athletic performance, according to Maciel, so you're probably better off skipping this one.
What it's for: Recovery
The claim: There are a quite a few reasons you might consider taking fish oil (including your heart health), but some athletes swear by the stuff to reduce inflammation and thus, muscle soreness.
The evidence: "Fish oil gets praise because of its omega-3 fatty acid content," Goodson says. "Omega-3s are essential fatty acids that can contribute to reducing inflammation at the cellular level."
Recommended dosage: Two to four grams per day is ideal, according to Goodson, although it's a good idea to check with your doctor before starting a higher dose. "You can also reap the benefits from eating foods like salmon, trout, tuna, soybeans, walnuts, and their oils," she notes.