Research
Micronutrients & recovery
Leucine supplementation can rescue muscle protein synthesis in older adults when protein doses are sub-optimal, but provides no additional benefit if the total protein dose is already sufficient (>35g).
If you can't eat a large meal (30g+ protein), adding a leucine-rich source (like whey or a leucine supplement) can help trigger muscle building. But if you are already eating a large, high-protein meal, you don't need extra leucine.
GoodQualifiesHIGH confidence
Importantly, additional leucine ingestion confers no significant benefit when the protein bolus provided is sufficient (>35 g) to maximally stimulate MPS [115]. However, supplementing a sub-optimal dose of protein with leucine can rescue the deficit in MPS, similar to ingesting a much greater dose of protein in older adults [58,112].
Why this rating
Supported by acute metabolic studies and mechanistic explanations.
Source
Nutritional Supplements to Support Resistance Exercise in Countering the Sarcopenia of Aging
James McKendry et al. · Nutrients · 2020
narrative_reviewCited 118×
Read the paper This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →