BCAAs: Are they worth the hype? Original paper

Limited evidence suggests that BCAAs might reduce muscle soreness and indirect markers of muscle damage in resistance-training people. However, studies demonstrating the benefits of BCAAs utilized non-protein comparator groups, and often failed to report information on participants’ total protein intake. BCAAs probably don’t have utility for people already consuming adequate protein and managing training volume appropriately.

This Study Summary was published on March 2 2022.

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Given the importance of protein for exercise, branched chain amino acids (BCAAs; isoleucine, leucine, and valine), which contribute heavily to muscle synthesis, are commonly marketed by supplement companies as being able to provide benefits for resistance training performance, recovery, and body composition. Are they effective, or a waste of money?

The study

This systematic review of 12 randomized controlled trials assessed the effects of BCAA supplementation on physical performance, muscle damage, and body composition.

Studies that met the following criteria were included:

  • Assessed healthy people who were at least 18 years old, without chronic disease.
  • Utilized BCAA supplementation in isolation compared to a matched control group.
  • Assessed physical performance, muscle damage, or body composition as an outcome.

The sample size of the included studies ranged from 9 to 46, with an average of about 22 participants per study. The studies were published between 2008 to 2018, and study length varied from 1 day to 8 weeks. The average BCAA dose was 19.5 grams per day and was compared to either water, carbohydrate, artificial sweetener, or taurine (a non-essential amino acid). Ten of the studies recruited nonathlete participants, one recruited experienced runners, and one recruited soccer and rugby athletes.

The results

Summary of included studies

Authors and yearStudy type and designSupplementation protocolFood controlFollow-up periodOutcome measuresResults
Uchida et al, 2008[1]
Double-blind crossover RCT with 17 healthy males
BCAA (77 mg/kg body weight) or placebo (maltodextrin)
Controlled diet with 16% protein
One day, with 7 days between supplementation protocols
Lactate, ammonia, total distance performed, perceived exertion, time to exhaustion
No statistically significant difference between groups
Jackman et al, 2010[2]
Blind RCT with 24 untrained males
BCAA (29.2 grams/day in four doses) or placebo (300 mL of artificially sweetened water)
Controlled diet with 55% CHO and 1.5 g/kg bw protein
Four days
CK, interleukin-6, myoglobin, strength, subjective muscle pain
No effect of BCAAs on CK, interleukin-6, myoglobin, or strength; lower subjective muscle pain in BCAA group
Greer et al, 2011 [3]
Double-blind crossover RCT with nine sedentary men
BCAA (24.3 grams) or CHO (30 grams) or PL (water), all supplements were consumed twice daily
Maintain usual diet
1 day, with 8 weeks between supplementation protocols
Total distance performed, perceived exertion, respiratory exchange ratio
Perceived exertion was lower in the BCAA group than PL
Howatson et al, 2012[4]
Double-blind RCT with 12 rugby and football male competitors
BCAA (20 grams/day) or PL (20 grams/day of aspartame), both supplements were consumed in two 10-gram portions
Maintain usual diet
12 days
CK, subjective muscle pain, MVC, vertical jump, and thigh and calf circumference.
CK and subjective muscle pain: lower in BCAA group; MVC: higher in BCAA group. Vertical jump, thigh and calf circumference: no effect of BCAAs
Spillane et al, 2012 [5]
Double-blind RCT with nineteen male non-athletes
BCAA (9 grams, 4 times per week, portioned in 12 capsules (6 pre-workout and 6 post-workout)) or PL (guar gum, 9 grams 4 times a week, portioned in 12 capsules)
Maintain usual diet
8 weeks
Body weight, body water, fat-free mass, fat mass, upper and lower limb strength
No effect of BCAAs
Kim et al, 2013[6]
Double-blind, cross-over RCT with 26 active men
BCAA (80 mg/kg body weight/day) or PL (500 ml of water with non-caloric artificial sweetener)
No data available
1 day, with 7 days between supplementation protocols
CK, lactate dehydrogenase, serotonin, ammonia, and lactate
CK and lactate dehydrogenase: no effect of supplementation. Serotonin and lactate: lower in the BCAA group. Ammonia: higher in BCAA group.
Ra et al, 2013 [7]
RCT with 36 untrained men
BCAA (9.6 grams/day), Taurine (6 grams/day), PL (starch, 9.6 grams/day when replacing BCAA or 6 grams/day when replacing taurine), forming the groups: PL+ PL, BCAA+ PL, PL + Taurine, or BCAA + Taurine
Maintain usual diet
18 days
CK, lactate dehydrogenase, aldolase, 8- hydroxydeoxyguanosine, subjective muscle pain
CK, lactate dehydrogenase, aldolase: no effect of BCAAs. 8- hydroxydeoxyguanosine: lower in BCAA + Taurine group. Subjective muscle pain: lower in BCAA + Taurine group than PL + PL group
Areces et al, 2014 [8]
Double-blind RCT with 46 experienced runners
BCAA (5 grams/day) or PL (1:1 ratio cellulose and dextrose, 5 grams/day)
Maintain usual diet
1 day
Vertical jump, lower limb strength and power, running speed, subjective muscle pain
No effect of BCAAs
Dudgeon et al, 2016 [9]
Double-blind RCT with 17 active men
BCAA (28 grams/day, portioned at 7 grams pre-workout and 21 g post-workout, 4 times a week) or PL (plant-based carbohydrate, 28 grams/day, portioned at 14 grams pre-workout and 14 grams post-workout, 4 times per week).
Training days 30% CHO, 35% protein, 35% fat. Days off 25% CHO, 40% protein, 35% fat
8 weeks
Body weight, lean mass, fat mass, muscle strength, repetitions to fatigue on squats and bench press, resting metabolic rate
Body weight, lean mass and lower limb strength: higher in BCAA group. Fat mass: lower in BCAA group. Repetitions to fatigue, squats: higher in PL group. Repetitions to fatigue bench press and resting metabolic rate: no effect of BCAAs
Fouré et al, 2016[10]
Double-blind RCT with 26 young healthy males
BCAA (100 mg/kg bw/day) or PL (microcrystalline cellulose). Three doses were taken on day 1, one dose per day on days 2–4
Maintain usual diet
6 days
CK, phosphocreatine, inorganic phosphate, MVC, maximal isometric force, power, subjective muscle pain
BCAAs did not affect any outcome
Ra et al, 2018[11]
Double-blind RCT with 15 untrained men
Pre BCAA (9.6 grams/day) or Post BCAA (composition equal to Pre BCAA) or PL for the entire period (starch, 9.6 grams/day); all supplements were consumed in three 3.2-gram portions
Maintain usual diet
7 days (3 days pre, 1 day protocol and 3 days post)
CK, lactate dehydrogenase, aldolase, beta-hydroxy-beta-methylbutyrate, arm circumference, subjective muscle pain
CK, lactate dehydrogenase, aldolase, arm circumference, and subjective muscle pain: lower in Pre BCAA group than PL group. Beta-hydroxy-beta-methylbutyrate: higher in pre BCAA group than PL group
Vandusseldorp et al, 2018[12]
Double-blind RCT with 20 active men
BCAA (0.22 grams/kg bw/day) or PL (maltodextrin), two equal doses (one in the morning and other in the evening)
Controlled diet with 1.2 grams/kg bw protein
8 days
CK, vertical jump, MVC, jump squat peak power, subjective muscle pain
CK and subjective muscle pain: lower in the BCAA group. Vertical jump, MVC, jump squat peak power: no effect of BCAAs

Blood parameters: Eight studies assessed the effects of BCAA supplementation on blood parameters associated with muscle damage. Seven of them assessed creatine kinase (CK), three assessed lactate dehydrogenase, two assessed lactate, two assessed aldolase, and one article assessed myoglobin and interleukin 6 (IL-6).

Of the seven studies assessing CK, three reported a decrease in CK in the BCAA group compared to placebo following an exercise protocol designed to induce muscle damage (24, 72–96, and 48 hours after exercise in each study, respectively).[4][11][12]

Of the three studies assessing lactate dehydrogenase and of the two studies assessing aldolase, one reported that both markers were lower 72 and 96 hours after an exercise protocol designed to induce muscle damage in a BCAA group, compared to placebo.[11]

Of the two studies assessing lactate, one found that it was lower in the BCAA group than the placebo group immediately after a cycling exercise protocol.[6]

The only study assessing myoglobin and IL-6 found no effect of BCAAs following an exercise protocol designed to induce muscle damage.[2]

Body composition: Two studies evaluated participant body weight and lean mass. One of these studies found that BCAAs prevented body weight and lean mass loss during an 8-week calorie-restricted diet, compared to a control group consuming a carbohydrate supplement.[9] Notably, the supplement used in the study demonstrating an effect of BCAAs also contained 1,000 mg of citrulline malate and 2,500 mg of L-glutamine. The placebo was a standard electrolyte sports beverage.


  • Repetitions performed: Three studies assessed repetitions performed, one of which reported that the BCAA group performed more squat exercise repetitions than a placebo group. The same study reported improvements in body composition.[9]
  • Total distance performed: Two studies assessed distanced performed, with no differences between groups in either study.
  • Strength: Five studies assessed strength, one of which reported a greater increase in 3RM strength on squats and bench press in the BCAA group, compared to the placebo group. The same study reported improvements in body composition.[9]
  • Vertical jump: Three studies assessed vertical jump performance, none of which found an effect of BCAAs.
  • Power: Three studies assessed power, none of which found an effect of BCAAs.
  • Perceived exertion: Two studies assessed perceived exertion, one of which found an improvement at 75 and 90 minutes during a cycling protocol in a group consuming BCAAs, compared to a group consuming a carbohydrate-based electrolyte beverage.[3]
  • Muscle soreness: Six studies assessed muscle soreness and pain, four of which found a reduction in subjective muscle pain in groups consuming BCAAs, compared to a placebo.[2][4][7][11] One reported an effect of BCAAs, as compared to an artificially-sweetened beverage 48 and 72 hours following an eccentric exercise protocol.[2] A second study reported that BCAAs reduced muscle soreness 24 and 48 hours after an exercise protocol designed to induce muscle damage, compared to an artificially-sweetened beverage.[4] A third study reported that consuming BCAAs with taurine reduced muscle soreness 48 hours after an exercise protocol designed to induce muscle damage as compared to a carbohydrate-based placebo,[7] and in another study, consuming BCAAs before an eccentric bicep curl protocol reduced muscle soreness at 72 and 96 hours, as compared to a starch-based placebo.[11]


While several studies demonstrated positive effects of BCAAs, several points must be considered:

  • The background protein intake of the participants probably moderated the benefits of BCAAs. Since BCAAs are three essential amino acids, and therefore found in protein food sources, BCAAs might be less useful for individuals already consuming adequate protein. Of the eight studies reporting benefits of BCAAs, three did not utilize a dietary control or report participants’ total protein intake, only requiring that participants maintain their usual dietary habits,[4] [11][7] and another study did not control participants’ dietary intakes nor provide information on their intake.[6] In one study, participants maintained an overall protein intake of about 1.2 grams per kg of body weight per day (g/kg/day), which the authors noted was lower than the recommended range for resistance training individuals (1.4–2.0 g/kg/day).[12] Another study utilized a calorie and carbohydrate-restricted diet, providing 35–40% of calories from protein.[9] One study asked participants to maintain their habitual intake while assessing their calorie and macronutrient intake during the study, reporting that the BCAA group derived about 69% of total energy from carbohydrates, while information was not provided on fat or protein intake.[3] One study provided all food to participants, providing 1.5 g/kg/day of protein to both BCAA and placebo groups.[2]
  • None of the studies compared BCAAs to another source of amino acids (e.g., a protein supplement or protein from food) except for one study utilizing both taurine and starch in comparator groups.[7]
  • Even if BCAAs were to provide a small benefit on markers of muscle damage or soreness, using BCAAs for this purpose might become redundant if training volume is managed appropriately to avoid excessive muscle damage in the first place.

The big picture

Several other review papers have been published assessing the utility of BCAAs for resistance-trained individuals. Here are a few that were published recently:

A 2021 meta-analysis[13] previously reviewed in Study Summaries assessing the effects of BCAAs on muscle soreness and markers of muscle damage found that BCAA supplementation reduced CK levels at less than 24 hours after exercise, as well as 24 and 48 hours after exercise, while improving muscle soreness at less than 24 hours only. However, the observed effects were small.

A 2021 narrative review[14] assessing the effects of BCAAs on muscle strength and hypertrophy concluded that “... the proposed benefits of BCAA used in the marketing of supplements appears to be at odds with the overall state of the current literature, which does not support the efficacy of supplementation on muscle strength and hypertrophy."

A 2017 meta-analysis[15] assessing the effects of BCAAs on muscle soreness and markers of muscle damage, reported that BCAAs reduces CK at less than 24 hours and 24 hours after exercise compared to a placebo, with no effects on lactate dehydrogenase or muscle soreness.

In a 2017 systematic review[16] assessing the effects of BCAAs on markers of muscle damage, 6 of 11 studies reported a beneficial effect of BCAAs.

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This Study Summary was published on March 2 2022.