Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In


Nutrition for Women

Sustained Energy

Hey, what’s not to love about BCAAs? Calorie-free, muscle-friendly and easy to drink during a workout, this is any active woman’s go-to supplement.

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.


Eating for a leaner, more muscular body is tricky business. When you cut calories, you’re trying to starve your fat but preserve your muscle (and hope your postworkout meals head to your delts or glutes, not your hips). Unfortunately, manipulating body composition is rarely a simple zero-sum game.

Related: 10 Tips For a Perfect Workout

Branched-chain amino acids (BCAAs) are the rare supplement that tips the metabolic process in the favor of your muscle tissue. BCAAs consist of three essential amino acids: leucine, valine, and isoleucine. Your body is not able to create BCAAs, acquiring them from dietary protein sources instead. BCAAs have certain special properties that make them different from other amino acids and highly valuable if you’re looking to improve your body composition.

What’s So Great About BCAAs?

Much research has been published showing that ingesting BCAAs around your training can give you a better workout, preserve more muscle by kick-starting muscle protein synthesis and even lead to less soreness the day after training. Many of the benefits can be traced back to the fact that leucine is one of the most potent known triggers of protein synthesis. It flips the switch on your body’s muscle-building machine.

• Provides energy during workouts: A calorie-free BCAA solution can be a girl’s BFF when trying to train intensely while dieting, especially when reducing carbs. BCAAs are metabolized by the muscle tissues and used as a form of energy, thereby sparing precious glycogen reserves. BCAAs also compete with the amino acid tryptophan for entry into the brain. Tryptophan is a precursor to serotonin, a pleasure chemical that can increase your perception of how fatiguing your workout really is. By blocking tryptophan from the brain, BCAAs help crank up the workout intensity.

• Builds muscle, burns fat: Several studies have shown that over time BCAAs improve body composition, increasing muscle mass while helping metabolize fat stores. A study published in The Journal of Strength and Conditioning Research investigated the effects of BCAA supplementation on the blood hormone levels of trained athletes. It found that when subjects consumed BCAAs around intense workouts, their blood showed elevated levels of muscle-building hormones and significantly lower levels of catabolic hormones.

• Stops muscle loss: “Based on the research from whey, BCAAs and leucine studies, by taking the right BCAA product during exercise you should see a down-regulation of the muscle catabolic cascade,” says Chris Lockwood, Ph.D., CSCS, a supplement researcher, formulator and chief scientific officer for 4Life Research. “It makes sense considering the role BCAAs play in energy metabolism at the cellular level. If your intracellular levels of BCAAs get depleted, the body will try to break down intracellular protein to make those available for energy demands.”

• Decreases soreness: The International Journal of Sport Nutrition and Exercise Metabolism published a study that put 12 females through a squat workout. Half the group was given a BCAA formula beforehand while the other half was given a simple sugar solution. The BCAA group reported feeling less sore in the days after the workout. Even more, three days later, the BCAA group was able to generate more force during a leg workout than the women who didn’t take BCAAs.

The BCAA Advantage

Whey protein is one of the best sources of BCAAs, one reason why the shaker-bottle favorite is so effective at initiating protein synthesis after a workout. If your diet is rich in protein and includes a dose of post-training whey, pat yourself on the back — you’re doing your body a favor. But if whey protein is loaded with BCAAs, why take a separate BCAA supplement? BCAAs are most effective when consumed immediately before, after and especially during your workout. If you are squatting, lunging, or doing any kind of interval training, a thick protein shake sloshing around in your stomach isn’t going to feel good. “Studies show that whey protein is very satiating, meaning it delivers a feeling of fullness. The last thing you want when you’re exercising is to feel too full,” Lockwood says.

In addition to the light consistency making them more appealing during a workout, another advantage of taking BCAAs separately is speed. They are able to pass more quickly through the gut and get to work providing energy to muscles.

But just because BCAAs are calorie-free, don’t make the mistake of thinking that you can build calorie-free muscle. The body still needs the full complement of amino acids to create muscle. That is why BCAAs are most effective when combined with a diet that includes whole-food protein sources as well as a quality whey protein.