Studies Favor BCAAs for 'Cut Diets'

Branched-chain amino acids (BCAAs) are one of the most highly researched and popular strength training supplements for muscle recovery. According to a paper published in 2017, BCAAs have been shown to help exercise-induced muscle damage and stimulate muscle protein synthesis (muscle growth) as long as additional amino acids are present. They are also linked to preserving lean mass during a “cut diet” which is restricting calories and carbohydrates during extensive physical training. Active adults to athletes typically have fitness goals that include gaining muscle while losing fat. This process requires a combination of cutting calories and exercise, unfortunately “poses a risk for lean tissue loss, which can limit performance." This is where BCAAs can help the most and we are going to take a look at how they benefit the body during caloric restriction in conjunction with heavy resistance training.

What Are BCAAs?

BCAAs are Linked to Muscle Growth and Fat Loss. mihailomilovanovic/Getty Images

Branched-chain amino acids (BCAAs) belong to an essential group containing leucine, isoleucine, and valine. Essential means the body doesn’t produce the amino acids and they must be consumed through our daily nutrition. This is easily done by eating lean meats or drinking whey protein which are high in BCAAs. A large percentage of branched-chain amino acids are found in our skeletal muscle and studies have shown leucine responsible for muscle protein synthesis (muscle growth). It’s no wonder BCAAs are “the most widely used supplements among natural bodybuilders.”

BCAAs and Exercise

Exercise-induced muscle damage (EIMD) occurs during a hard workout and we are basically tearing down our lean tissue. The following day, side effects of EIMD are felt through increased muscle soreness, reduced range of motion and function along with swelling. Branched-chain amino acids (BCAAs) taken before and after workouts have shown to “stimulate muscle protein synthesis leading to post-exercise muscle recovery, allowing consumers to train longer at a higher intensity.”

Other positive feedback is improved athletic performance in addition to muscle preservation with BCAA supplementation. In 2012, The Journal of the International Society of Sports Nutrition reported BCAAs taken before and after resistance training accelerated muscle recovery and improved muscle function.

BCAAs and Caloric Restriction

Cutting or “cut diets” are popular among athletes but active adults trying to lose weight are also implementing the technique. Cut diets refer to restricting calories and carbohydrates in an effort to reduce carbohydrate stores and force the body to burn fat for fuel. The goal of the strategy is to promote fat loss but the problem with caloric restriction is risking significant muscle loss as well. Restricting calories and essential nutrients can also lead to decreased athletic performance, increased illness and training injuries. Insufficient protein intake simply doesn’t do an active body well and promotes muscle wasting rather than growth.

There is an abundant amount of research indicating “preserving muscle mass requires ingesting a sufficient amount of high-quality protein.” Many athletes and physically active adults are consuming protein with branched-chain amino acids (BCAAs) to stimulate muscle growth and help with exercise recovery. In 2016, the Journal of the International Society of Sports Nutrition clinical findings showed BCAA supplementation under caloric restriction and heavy resistance training maintained lean mass and improved recovery using it pre and post-workout.

4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?J Int Soc Sports Nutr. 2017;14:30. doi:10.1186/s12970-017-0184-9

  2. Dudgeon WD, Kelley EP, Scheett TP. In a single-blind, matched group design: branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted dietJ Int Soc Sports Nutr. 2016;13:1. doi:10.1186/s12970-015-0112-9

  3. Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementationJ Int Soc Sports Nutr. 2014;11:20. doi:10.1186/1550-2783-11-20

  4. Stark M, Lukaszuk J, Prawitz A, Salacinski A. Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-trainingJ Int Soc Sports Nutr. 2012;9(1):54. doi:10.1186/1550-2783-9-54

By Darla Leal
Darla Leal is a Master Fitness Trainer, freelance writer, and the creator of Stay Healthy Fitness, where she embraces a "fit-over-55" lifestyle.