Supplements

When to Take BCAAs: Before, During, or After a Workout?

Written by Kat Kennedy, NASM CPT, NCSF CPT, NCSF SNS
Medically Reviewed by Felicia Newell, M.S., RDN

Updated on September 12, 2024

Unless you’re superhuman, there’s a high probability that you’ll feel sore and fatigued after working out. This is a big reason why high-level athletes and everyday fitness enthusiasts alike turn to a BCAA supplement for support.

So far, the research has shown that BCAAs can limit post-workout soreness, delay fatigue during exercise, encourage muscle growth and repair, and provide muscles with much-needed energy to keep going.

But in order to reap these benefits…do you need to take them at a certain time?

I reached out to a registered dietitian to ask. Keep reading to hear what she has to say.

Table Of Contents

But First, What Are BCAAs? A Quick Overview

You can think of branched-chain amino acids, or BCAAs, as a subgroup of amino acids…

Amino acids are the molecular building blocks of proteins in the human body and in the food you eat. Here’s a quick breakdown…

There are a total of 20 different amino acids, 9 of which are considered “essential.” Essential just means that your body can’t make them on its own, so they need to be obtained from food and/or supplements like protein powder or collagen peptides.

Of those nine, three are branched-chain amino acids (BCAAs)—leucine, isoleucine, and valine. “Branched” just refers to their chemical structure. Rather than having a straight structure like other amino acids, BCAAs resemble a branch or a fork.

Don’t worry, you don’t need to memorize any of this. The big takeaway is that these three essential BCAAs have been shown to turn on a process called muscle protein synthesis—which is how your body repairs and builds muscle tissue.

Next, we’ll discuss the benefits you can expect when taking BCAAs before, during, and after a workout.

Benefits of Taking BCAAs Before a Workout

Taking BCAAs before a workout can help delay fatigue and provide extra energy reserves for your muscles. Some studies have even shown that taking BCAAs before a workout can help prevent muscle loss, especially if you are in a calorie deficit. 

For example, a 2016 study of 17 male athletes aged 21 to 28 determined that BCAA supplements allowed them to maintain lean muscle, preserve muscle mass, and lose fat mass while engaged in resistance training (1).

The researchers split the men into two groups: one had branched-chain amino acids before working out, and the other had only carbohydrates. When the carb group did bodybuilding-style workouts and ate fewer calories, they lost body fat and muscle mass. But the BCAA group? They just lost body fat while keeping their muscle mass.

NativePath Blog Post Image

Benefits of Taking BCAAs During a Workout

Taking BCAAS during a workout may help reduce fatigue and boost hydration by improving cellular rehydration. This helps your cells keep their shape and function optimally (2).  

Serotonin is a hormone that naturally rises in response to exercise. However, if the levels get too high, it can cause muscle fatigue, especially during long-duration endurance training.

Some studies have suggested that BCAAs can lower the concentration of serotonin in the body, particularly when performing endurance training for more than an hour (3). However, it's not yet clear if you can reap the same benefits from shorter training sessions.

Benefits of Taking BCAAs After a Workout

By taking BCAAs after a workout, your body will get the oomph it needs to repair, rebuild, and refresh its muscles. For this reason, this is my favorite time to take BCAAs, as it helps alleviate that next-day soreness.

A 2017 study confirms this, stating that due to BCAA’s ability to reduce muscle damage and loss of strength, having BCAAs post-exercise is associated with better muscle recovery (4). 

Another study also found that athletes who took BCAA powder after intensive endurance training experienced less muscle soreness and fatigue than those taking a placebo (5). This is great news if you need a post-workout supplement to help you recover more effectively.

NativeNote: If you exercise in the evening, taking BCAAs late at night could make it harder to drift off since they can suppress the release of serotonin, which is involved in sleep regulation.

So…When Is The Best Time to Take BCAAs?

As you’ve seen throughout this article, there are pros to taking BCAAs before, during, and after exercising. But which is best?

Some say it doesn’t really matter…that when it comes down to it, far more research has concluded that the total amount of leucine you consume in a day is more important than what time you take it (6).

Although there may not be a “best” time to take BCAAs, taking them around the time you work out would be a good idea. (Peak BCAA levels occur approximately 30 minutes after ingestion (7).)

That said, keep a jar of BCAAs in your gym bag so that you never miss out on supplementation. This will keep your muscles in working order by supporting muscle recovery and limiting next-day soreness.

Can I Take BCAAs on an Empty Stomach?

Yes, you can take BCAAs on an empty stomach. However, if you have a sensitive stomach or you're just getting started with supplements, you might feel some mild digestive discomfort when taking BCAAs on an empty stomach.

How Much BCAAs Should I Take?

Regardless of when you take your BCAAS, “research shows that a 3-5 gram serving of BCAAs is a good amount for most women,” says Smith. Your body weight will play a role in determining the appropriate amount of BCAAs to take, but this is a solid starting estimate for most people. 

For men, a good BCAA dosage to go by is between 5-12 grams.

Kat Kennedy
Article by

Kat Kennedy

Kat Kennedy is the Fitness and Nutrition Editor at NativePath. With a NASM CPT, NCSF CPT, and NCSF Sports Nutrition Certification, she has a passion for giving people the tools they need to feel healthy, strong, and confident.

Read More
Share onfacebook

    Medical Disclaimer

    This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Chad Walding nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.

    Leave a Comment