Branched-Chain Amino Acids (BCAAs) and Creatine: Efficacy for Muscle Mass and Strength

In sports nutrition, BCAAs and creatine are two of the most used supplements. Here’s what primary research says about their effects on muscle growth, strength, and recovery—plus when EAAs may be a smarter option than BCAAs alone.

BCAAs (Leucine, Isoleucine, Valine)

BCAAs are essential amino acids involved in muscle protein metabolism. Their most consistent roles in the literature are preserving lean mass during calorie deficits and modestly aiding recovery.

Lean mass in a caloric deficit

In resistance-trained males on a hypocaloric diet, BCAA supplementation helped maintain lean mass while fat mass decreased, versus carbohydrate control. Strength on squat/bench also improved in the BCAA group in that cut phase trial (JISSN 2016).

Muscle protein synthesis (MPS): BCAAs vs. complete protein/EAAs

After resistance exercise, 5.6 g BCAAs increased myofibrillar MPS versus placebo over 4 hours (Jackman et al., 2017). However, expert reviews show BCAAs alone provide only part of the substrates needed for new muscle protein. Compared with complete protein or all-nine EAAs, BCAAs alone are consistently inferior for stimulating MPS and net protein balance (Wolfe, 2017).

Recovery & soreness

A 2024 systematic review and meta-analysis reports BCAAs reduce post-exercise muscle soreness (DOMS) from ~24–96 h and can lower CK immediately and at 72 h after exercise-induced muscle damage (Sports Medicine Open 2024; PubMed mirror PMID: 38625669).

Creatine

Creatine monohydrate is among the most studied ergogenic aids. Position stands and numerous trials support its benefits for high-intensity performance, lean mass accrual, and strength when combined with resistance training.

Muscle mass & strength

The International Society of Sports Nutrition’s position stand concludes creatine is the most effective supplement for increasing high-intensity exercise capacity and lean body mass during training (Kreider et al., JISSN 2017). Earlier ISSN statements echo this consensus (ISSN Position, 2007).

Mechanisms

1. Phosphocreatine/ATP availability: more total work and training volume per session.
2. Cell signaling & satellite cells: supports repair/growth pathways.
3. Cell hydration: osmotic changes that may favor anabolism.
4. Myostatin modulation: with training, creatine has been linked to greater reductions in serum myostatin versus training alone (Saremi et al., 2010).

Safety

Creatine is well-researched and considered safe for healthy individuals at standard doses (3–5 g/day) with or without an initial loading strategy (JISSN 2017).

Combining BCAAs and Creatine

Some athletes stack BCAAs (or better, EAAs/complete protein) with creatine to cover both substrate (amino acids) and energy/phosphagen systems. Direct research on the combo is limited; most evidence is from trials on each supplement independently.

Considerations & Potential Side Effects

BCAAs

Generally well-tolerated. Emerging critiques suggest BCAAs alone do not reliably increase net anabolism compared with complete protein/EAAs and should not replace them (Wolfe, 2017). Monitor GI tolerance and overall protein balance.

Creatine

Possible transient weight increase (water), occasional GI upset or cramps in some users; overall safety profile is strong at recommended intakes (JISSN 2017).

Bottom Line

• BCAAs: Useful in cuts for lean-mass preservation and for easing soreness/recovery, but inferior to complete protein/EAAs for building muscle.
• Creatine: Robust, consistent improvements in strength, high-intensity performance, and lean mass when paired with resistance training.

Upgrade Your Amino Coverage

If you want precise, low-calorie amino coverage—especially around training or when appetite is low—consider EAAs rather than BCAAs alone.

References (Primary Sources)