The Best Supplements to Build Muscle

How do muscles become stronger? Oddly enough, by becoming weaker first. When muscles are worked hard, they actually break down. The muscle fibers stretch and tear. As they heal, though, the fibers grow bigger and stronger. They do this mostly by incorporating protein to build new muscle tissue.

For most people, a healthy diet is more than enough to encourage muscles to get stronger. But those looking to speed that process along often add supplements to their diet.

Do these supplements work? Research is mixed, says Angel Planells, a Seattle-based registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics. "My goal would be for folks to have good quality nutrition, adequate hydration and a solid workout plan that will help promote muscle growth. Supplements can work, but we can obtain several of these products through food," he says.

Indeed, the vast majority of Americans consume more than enough protein; have you ever heard of anyone suffering a protein deficiency? (Only fully vegan vegetarians and those with some rare health conditions may need to add protein supplements to their diet.) "One certainly does not need to eat more than recommended amounts at one time to build muscle," says Yasi Ansari, a registered dietitian and certified specialist in sports dietetics based in Los Angeles and also a spokesperson for the Academy of Nutrition and Dietetics.

[SEE: How to Eat for Healthy Muscles.]

That said, here is what you need to know about muscle-building supplements.

Protein Shakes

A first choice among many athletes is the protein shake. Consider this simple option: "Low-fat chocolate milk is a great and easy choice for muscle building and recovery," Planells says. "Milk can serve as a more economical option to a more expensive protein drink."

Adding a protein powder "can support an athlete in meeting their protein needs if they are unable to meet their recommended needs via food," Ansari says. She recommends spreading the protein intake evenly throughout the day. And Planells warns elite competitive athletes to "do your research to make sure that the protein shake you are consuming does not contain substances banned by college and professional sporting agencies, if applicable."

In addition, while some extra protein may help rebuild muscle after working out, be mindful that consuming an excessive amount of protein can be harmful to your liver and kidneys. "Consult with a registered dietitian nutritionist to help get an idea of the amount needed for your desired sporting activities and to help you accomplish your goals," Planells says.

Amino Acids

The body uses nine essential amino acids to build proteins, and of those nine, three are called branched-chain amino acids, or BCAAs: leucine, isoleucine and valine. These are found in protein-rich foods, like meat, eggs and dairy products. They are also sold as a dietary supplement, most often as a powder.

"Some people love hyping up BCAAs," Planells says. "However, if we consume a wide variety of foods, you will consume an adequate amount of these amino acids, so spend your money on good quality food to help get your BCAAs, as it comes in meat, poultry, fish, eggs, dairy products, nuts, seeds, soy, beans, peas and lentils."

[SEE: 5 Muscle-Building Nutrients That Aren't Protein.]

Leucine, for example, is an amino acid that helps to trigger muscle growth. "It's like the light switch that helps turn the body's muscle-building function on within the body," Ansari says. "Eating enough throughout the day can help to stimulate pathways within the muscle that help support muscle building." You can meet leucine requirements by consuming about 20-30 grams of protein at each meal, she says.

Creatine, another amino acid, may also play a role in increasing muscle. Maximizing creatine stores will allow an athlete to train harder and recover quickly, but it has to be used with a progressive resistance weight-training program. "If I consume creatine without working out, it's not going to have the same effect," Planells says. "Plus, consuming protein-rich foods can generally supply a gram of creatine per day. Not to be a Debbie Downer, but save your money and spend it on some high-quality protein foods."

Other Options

"There are a lot of anecdotal things out there, and unfortunately the data is mixed on several of these products," Planells says. "There are also some potential side effects which may hamper your exercise routine. Because your friend Bobby or Susan had good results doesn't mean the same will apply to you."

Among these are:

-- Antioxidants, like vitamins C and E.

-- Sodium bicarbonate, alleged to reduce lactic acid buildup and fatigue.

-- Citrulline, an amino acid that supposedly dilates blood vessels, which increases delivery of oxygen and nutrients to your muscles.

-- Betaine, a chemical compound that may increase creatine production, blood nitric acid levels or water retention in cells.

-- HMB, a biochemical that may help stressed and damaged muscle cells restore their structural integrity and function.

[READ: Muscle Recovery After Workouts.]

What Else to Know

-- Choose food first. "Generally, most individuals can take protein supplements and meet daily protein needs via foods," Ansari says. Planells agrees: "You can't supplement yourself to the finish line without a sound nutrition game plan. Make sure that you consume a wide variety of foods that will fuel your body for the activities that you are doing. By consuming quality carbohydrates, lean protein and healthy fats at every meal and snack opportunity, we provide the nutrients that will help to fuel this muscle growth. Consume a protein-rich snack after a strength-training session and replace carbohydrates after a hard aerobic workout."

-- Buyer beware. If you are purchasing supplements, "look for third-party testing on the label to ensure the product has been tested for quality and that it actually contains what it states on the label," Ansari says. "When looking for protein supplements, a good place to start is with products that contain isolated forms of protein, for example, whey protein isolate."

-- Timing is key. "More protein at one time is not necessarily better. It is recommended to spread your protein intake throughout the day for best benefits. And when consuming protein from foods, consume high-quality protein sources," Ansari says.

-- Put in the work. "To help build muscle, there are unfortunately no shortcuts. It will take hard work in the gym and planning to have adequate fuel around your workout day, whether you are a high school or college student, a 50-year-old empty nester or a 70-year-old that wants to build up strength and balance to prevent falls," Planells says.