Training Compounds
Evidence: strong_human
The 9 essential amino acids (leucine, isoleucine, valine, lysine, methionine, phenylalanine, threonine, tryptophan, histidine) cannot be synthesized endogenously and must be consumed. Leucine is the primary mTORC1 activator (via Sestrin2 and CASTOR1 sensors), triggering p70S6K and 4E-BP1 phosphorylation to initiate muscle protein synthesis (MPS). The remaining EAAs are required as substrates for the actual protein synthesis — leucine signals the process, but all 9 EAAs must be present to complete it. EAA supplementation achieves comparable MPS stimulation to whey protein with fewer total calories.
Standard: 6-12g per serving
Maintenance: 6-12g peri-workout
Administration: oral
Timing: Intra-workout (sipped during training) or immediately post-workout. Can also be used between meals to maintain elevated MPS throughout the day.
Duration: ongoing during training periods
EAAs have largely superseded BCAAs in evidence-based supplementation. BCAAs alone cannot drive complete MPS — they signal initiation but the other 6 EAAs are needed as building blocks. The 'leucine threshold' (2.5-3g per feeding) triggers maximal MPS — ensure EAA products contain adequate leucine. EAAs are particularly valuable for fasted training, caloric deficit, or between protein-containing meals to maintain the MPS 'muscle full' effect. For most clients, a high-quality whey protein provides all EAAs and is more cost-effective — EAA supplements are for specific timing and caloric efficiency goals.
Look for full EAA profile (all 9), not just BCAAs (leucine, isoleucine, valine only — which are insufficient to stimulate complete MPS). Fermented/plant-derived amino acids vs synthetic (both are effective). Leucine content should be 2.5-3.5g per serving. Instantized powder for mixability. Brands: Kion Aminos, PureBulk EAA, Thorne Amino Complex.
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