FitProven
Evidence Breakdown
Based on 3 studies
Evidence map
For & against, at a glance
Systematic Review
Neutral
Fouré A & Bendahan D · 2017NutrientsPRISMA systematic review of 11 studies of BCAA supplementation and exercise-induced muscle damage. The verdict is heavily conditional, and the conditions are the finding: BCAA "can be efficacious on outcomes of exercise-induced muscle damage, as long as the extent of muscle damage was low-to-moderate, the supplementation strategy combined a high daily BCAA intake (>200 mg·kg⁻¹·day⁻¹) for a long period of time (>10 days); it was especially effective if taken prior to the damaging exercise." Heterogeneity across the 11 studies was high and risk of bias was moderate (six studies rated positive, three neutral on the Quality Criteria Checklist). Note that hypertrophy was **not** an outcome of this review — it assessed indirect markers of muscle damage only, so it cannot speak to muscle growth either way. The typical consumer protocol (a low dose, taken only around a workout, without meeting the >200 mg/kg/day and >10-day conditions) is not the protocol this review found to work.
0.50
PRISMA systematic review of 11 studies of BCAA supplementation and exercise-induced muscle damage. The verdict is heavily conditional, and the conditions are the finding: BCAA "can be efficacious on outcomes of exercise-induced muscle damage, as long as the extent of muscle damage was low-to-moderate, the supplementation strategy combined a high daily BCAA intake (>200 mg·kg⁻¹·day⁻¹) for a long period of time (>10 days); it was especially effective if taken prior to the damaging exercise." Heterogeneity across the 11 studies was high and risk of bias was moderate (six studies rated positive, three neutral on the Quality Criteria Checklist). Note that hypertrophy was **not** an outcome of this review — it assessed indirect markers of muscle damage only, so it cannot speak to muscle growth either way. The typical consumer protocol (a low dose, taken only around a workout, without meeting the >200 mg/kg/day and >10-day conditions) is not the protocol this review found to work.
Design Systematic Review (0.9) × quality 0.55 = impact 0.50
View sourceRCT
Neutral
Jackman SR et al. · 2017Frontiers in PhysiologyCrossover trial in 10 young resistance-trained men who ingested either 5.6 g of BCAAs or a placebo immediately after resistance exercise (there was **no whey arm** — the two randomised conditions were BCAA and placebo). Myofibrillar protein synthesis over the following 4 h was 22% higher with BCAAs than with placebo (0.110 ± 0.009 vs 0.090 ± 0.006 %/h; P = 0.012), and mTORC1 signalling (S6K1-Thr389, PRAS40) was also greater. The paper's own stated conclusion is therefore *positive*: "ingesting BCAAs alone increases the post-exercise stimulation of myofibrillar-MPS". The case against BCAAs comes from the discussion, not from a randomised comparison: the authors note that this 22% rise is roughly **half** the ~50% rise the same group had previously reported for the same BCAA dose delivered inside 20 g of intact whey (Witard et al.), and argue that BCAAs alone are a sub-maximal stimulus because the other essential amino acids must come from muscle protein breakdown. That whey contrast is a comparison against previously published data, not against a randomised arm in this trial.
0.32
Crossover trial in 10 young resistance-trained men who ingested either 5.6 g of BCAAs or a placebo immediately after resistance exercise (there was **no whey arm** — the two randomised conditions were BCAA and placebo). Myofibrillar protein synthesis over the following 4 h was 22% higher with BCAAs than with placebo (0.110 ± 0.009 vs 0.090 ± 0.006 %/h; P = 0.012), and mTORC1 signalling (S6K1-Thr389, PRAS40) was also greater. The paper's own stated conclusion is therefore *positive*: "ingesting BCAAs alone increases the post-exercise stimulation of myofibrillar-MPS". The case against BCAAs comes from the discussion, not from a randomised comparison: the authors note that this 22% rise is roughly **half** the ~50% rise the same group had previously reported for the same BCAA dose delivered inside 20 g of intact whey (Witard et al.), and argue that BCAAs alone are a sub-maximal stimulus because the other essential amino acids must come from muscle protein breakdown. That whey contrast is a comparison against previously published data, not against a randomised arm in this trial.
Design RCT (0.8) × quality 0.40 = impact 0.32
View sourceNarrative Review
Con
Wolfe RR · 2017Journal of the International Society of Sports NutritionThis review concluded that BCAAs alone cannot promote muscle protein synthesis to a greater extent than the rate at which other essential amino acids become available. The claim that BCAAs stimulate muscle protein synthesis independently of other amino acids was not supported. The author argued that a complete protein source is necessary for a meaningful anabolic response.
0.17
This review concluded that BCAAs alone cannot promote muscle protein synthesis to a greater extent than the rate at which other essential amino acids become available. The claim that BCAAs stimulate muscle protein synthesis independently of other amino acids was not supported. The author argued that a complete protein source is necessary for a meaningful anabolic response.
Design Narrative Review (0.3) × quality 0.55 = impact 0.17
View sourceSystematic Review
Neutral
Fouré A & Bendahan D · 2017NutrientsPRISMA systematic review of 11 studies of BCAA supplementation and exercise-induced muscle damage. The verdict is heavily conditional, and the conditions are the finding: BCAA "can be efficacious on outcomes of exercise-induced muscle damage, as long as the extent of muscle damage was low-to-moderate, the supplementation strategy combined a high daily BCAA intake (>200 mg·kg⁻¹·day⁻¹) for a long period of time (>10 days); it was especially effective if taken prior to the damaging exercise." Heterogeneity across the 11 studies was high and risk of bias was moderate (six studies rated positive, three neutral on the Quality Criteria Checklist). Note that hypertrophy was **not** an outcome of this review — it assessed indirect markers of muscle damage only, so it cannot speak to muscle growth either way. The typical consumer protocol (a low dose, taken only around a workout, without meeting the >200 mg/kg/day and >10-day conditions) is not the protocol this review found to work.
0.50
PRISMA systematic review of 11 studies of BCAA supplementation and exercise-induced muscle damage. The verdict is heavily conditional, and the conditions are the finding: BCAA "can be efficacious on outcomes of exercise-induced muscle damage, as long as the extent of muscle damage was low-to-moderate, the supplementation strategy combined a high daily BCAA intake (>200 mg·kg⁻¹·day⁻¹) for a long period of time (>10 days); it was especially effective if taken prior to the damaging exercise." Heterogeneity across the 11 studies was high and risk of bias was moderate (six studies rated positive, three neutral on the Quality Criteria Checklist). Note that hypertrophy was **not** an outcome of this review — it assessed indirect markers of muscle damage only, so it cannot speak to muscle growth either way. The typical consumer protocol (a low dose, taken only around a workout, without meeting the >200 mg/kg/day and >10-day conditions) is not the protocol this review found to work.
Design Systematic Review (0.9) × quality 0.55 = impact 0.50
View sourceRCT
Neutral
Jackman SR et al. · 2017Frontiers in PhysiologyCrossover trial in 10 young resistance-trained men who ingested either 5.6 g of BCAAs or a placebo immediately after resistance exercise (there was **no whey arm** — the two randomised conditions were BCAA and placebo). Myofibrillar protein synthesis over the following 4 h was 22% higher with BCAAs than with placebo (0.110 ± 0.009 vs 0.090 ± 0.006 %/h; P = 0.012), and mTORC1 signalling (S6K1-Thr389, PRAS40) was also greater. The paper's own stated conclusion is therefore *positive*: "ingesting BCAAs alone increases the post-exercise stimulation of myofibrillar-MPS". The case against BCAAs comes from the discussion, not from a randomised comparison: the authors note that this 22% rise is roughly **half** the ~50% rise the same group had previously reported for the same BCAA dose delivered inside 20 g of intact whey (Witard et al.), and argue that BCAAs alone are a sub-maximal stimulus because the other essential amino acids must come from muscle protein breakdown. That whey contrast is a comparison against previously published data, not against a randomised arm in this trial.
0.32
Crossover trial in 10 young resistance-trained men who ingested either 5.6 g of BCAAs or a placebo immediately after resistance exercise (there was **no whey arm** — the two randomised conditions were BCAA and placebo). Myofibrillar protein synthesis over the following 4 h was 22% higher with BCAAs than with placebo (0.110 ± 0.009 vs 0.090 ± 0.006 %/h; P = 0.012), and mTORC1 signalling (S6K1-Thr389, PRAS40) was also greater. The paper's own stated conclusion is therefore *positive*: "ingesting BCAAs alone increases the post-exercise stimulation of myofibrillar-MPS". The case against BCAAs comes from the discussion, not from a randomised comparison: the authors note that this 22% rise is roughly **half** the ~50% rise the same group had previously reported for the same BCAA dose delivered inside 20 g of intact whey (Witard et al.), and argue that BCAAs alone are a sub-maximal stimulus because the other essential amino acids must come from muscle protein breakdown. That whey contrast is a comparison against previously published data, not against a randomised arm in this trial.
Design RCT (0.8) × quality 0.40 = impact 0.32
View sourceNarrative Review
Con
Wolfe RR · 2017Journal of the International Society of Sports NutritionThis review concluded that BCAAs alone cannot promote muscle protein synthesis to a greater extent than the rate at which other essential amino acids become available. The claim that BCAAs stimulate muscle protein synthesis independently of other amino acids was not supported. The author argued that a complete protein source is necessary for a meaningful anabolic response.
0.17
This review concluded that BCAAs alone cannot promote muscle protein synthesis to a greater extent than the rate at which other essential amino acids become available. The claim that BCAAs stimulate muscle protein synthesis independently of other amino acids was not supported. The author argued that a complete protein source is necessary for a meaningful anabolic response.
Design Narrative Review (0.3) × quality 0.55 = impact 0.17
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Evidence
AGAINST (1)
AGAINST Narrative Review0.55 Wolfe RR (2017)
BCAAs alone cannot raise muscle protein synthesis beyond the rate at which the other essential amino acids become available; a complete protein source is required for a meaningful anabolic response
This review concluded that BCAAs alone cannot promote muscle protein synthesis to a greater extent than the rate at which other essential amino acids become available. The claim that BCAAs stimulate muscle protein synthesis independently of other amino acids was not supported. The author argued that a complete protein source is necessary for a meaningful anabolic response.
Weighted 0.55 — Narrative review with no systematic search and no pooled sample. The mechanistic argument is sound and independently corroborated, but independence is poor in the exact direction of the conclusion: the author holds equity in an essential-amino-acid product company and consults for an amino-acid therapeutics firm, and the paper's conclusion is that EAAs rather than BCAAs are what people need. Downgraded for that conflict, not for the reasoning.
Funding: No study funding declared; the author discloses equity in Essential Blends LLC and consulting for Axcella LLC, plus grants/honoraria from Abbott Nutrition, Danone, PepsiCo and the National Cattlemen's Beef Checkoff
Journal of the International Society of Sports Nutrition
NEUTRAL (2)
NEUTRAL Systematic Review0.55 Fouré A, Bendahan D (2017)
BCAA can reduce indirect markers of exercise-induced muscle damage, but only under three conditions the authors specify: the muscle damage is low-to-moderate, the daily BCAA intake is high (>200 mg/kg/day), and supplementation is sustained for a long period (>10 days) - and it is especially effective taken prior to the damaging exercise. Hypertrophy was not an outcome of the review
PRISMA systematic review of 11 studies of BCAA supplementation and exercise-induced muscle damage. The verdict is heavily conditional, and the conditions are the finding: BCAA "can be efficacious on outcomes of exercise-induced muscle damage, as long as the extent of muscle damage was low-to-moderate, the supplementation strategy combined a high daily BCAA intake (>200 mg·kg⁻¹·day⁻¹) for a long period of time (>10 days); it was especially effective if taken prior to the damaging exercise." Heterogeneity across the 11 studies was high and risk of bias was moderate (six studies rated positive, three neutral on the Quality Criteria Checklist). Note that hypertrophy was not an outcome of this review — it assessed indirect markers of muscle damage only, so it cannot speak to muscle growth either way. The typical consumer protocol (a low dose, taken only around a workout, without meeting the >200 mg/kg/day and >10-day conditions) is not the protocol this review found to work.
Weighted 0.55 — k=11 studies with no pooled total reported (individual trials ranged from 9 to 30 participants) and no meta-analysis, so the 'moderate evidence' verdict rests on small, heterogeneous trials. Independently funded by CNRS with no declared conflicts.
Funding: Centre National de la Recherche Scientifique (CNRS UMR 7339)
Nutrients
NEUTRAL RCTn=10INDUSTRY0.40 Jackman SR, Witard OC et al. (2017)
BCAA raised myofibrillar protein synthesis 22% above placebo (P = 0.012), but that response was roughly half of what had previously been reported for the same BCAA dose delivered inside 20 g of intact whey
Crossover trial in 10 young resistance-trained men who ingested either 5.6 g of BCAAs or a placebo immediately after resistance exercise (there was no whey arm — the two randomised conditions were BCAA and placebo). Myofibrillar protein synthesis over the following 4 h was 22% higher with BCAAs than with placebo (0.110 ± 0.009 vs 0.090 ± 0.006 %/h; P = 0.012), and mTORC1 signalling (S6K1-Thr389, PRAS40) was also greater. The paper's own stated conclusion is therefore positive: "ingesting BCAAs alone increases the post-exercise stimulation of myofibrillar-MPS". The case against BCAAs comes from the discussion, not from a randomised comparison: the authors note that this 22% rise is roughly half the ~50% rise the same group had previously reported for the same BCAA dose delivered inside 20 g of intact whey (Witard et al.), and argue that BCAAs alone are a sub-maximal stimulus because the other essential amino acids must come from muscle protein breakdown. That whey contrast is a comparison against previously published data, not against a randomised arm in this trial.
Weighted 0.40 — n=10 in a crossover -- and whey was NOT a randomised arm. The headline whey-beats-BCAA contrast is against the authors' own previously published data, so the load-bearing comparison is non-randomised and indirect. The endpoint is an acute protein-synthesis surrogate measured over hours, not hypertrophy. Industry-funded (GSK) despite the paper declaring an absence of commercial relationships.
Funding: GlaxoSmithKline Healthcare (research grant)
Frontiers in Physiology