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Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 2:30 am
by LatinoBulk
Is the 3g leucine threshold still the gold standard for triggering MPS in older athletes?
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 3:05 am
by AndeanLifter
Recent data suggests 4g might be necessary for those over 50 due to anabolic resistance.
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 3:45 am
by TropicStrength
The mTOR pathway sensitivity definitely declines with age. Dosage timing matters more now.
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 4:32 am
by CaliFlex
Does the source matter? Whey vs Soy in terms of leucine kinetics?
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 5:15 am
by MedellinMuscle
Whey is always superior for the leucine spike. Soy just doesn't hit the same peak concentration.
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 5:50 am
by LatinoBulk
But if you equate for leucine content, does the total protein source still matter?
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 6:25 am
by AndeanLifter
Trommelen's work suggests that as long as leucine is equated, MPS rates are similar.
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 7:10 am
by TropicStrength
What about the other EAAs? You can't just trigger with leucine and expect magic without the building blocks.
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 7:40 am
by CaliFlex
Correct. Leucine is the spark, but the EAAs are the fuel.
Re: Leucine Threshold and Muscle Protein Synthesis
Posted: Thu Jan 22, 2026 8:15 am
by MedellinMuscle
I think a lot of people miss the "refractory period" of MPS. You can't just keep spiking it.