The International Society of Sports Nutrition Reviewed Decades of EAA Research. Here Are Their 10 Conclusions.
Why the world's leading sports nutrition body says essential amino acids are critical for muscle maintenance — especially after 40.
Summarised by Sam Ayres, Founder of Bare | Source: ISSN Position Stand, Journal of the International Society of Sports Nutrition, 2023
30-Day Money-Back Guarantee | Free Shipping Over R1000
In 2023, the International Society of Sports Nutrition (ISSN) published their official position stand on essential amino acid supplementation. Led by Dr. Arny Ferrando at the Center for Translational Research in Aging and Longevity at the University of Arkansas for Medical Sciences, a team of leading exercise science and human performance experts reviewed decades of research on EAAs.
Their goal: provide a definitive scientific reference on the effects of EAA supplementation on muscle maintenance and performance — for athletes, practitioners, and everyday people trying to stay strong as they age.
The result was 10 official conclusions. We've summarised each one below — and explained what it means if you're over 40.
Conclusion 1: EAAs Are the Foundation of Muscle Repair
ISSN finding: Initial studies on EAAs highlight their primary role in stimulating muscle protein synthesis and protein turnover. Protein turnover is critical for replacing degraded or damaged muscle proteins, and is the metabolic foundation for enhanced functional performance.
What this means after 40:
Your body is constantly breaking down and rebuilding muscle proteins. This cycle — protein turnover — is how you recover from training, maintain strength, and stay functional. After 40, this process slows. EAAs are the raw input that keeps the cycle running. Without enough of them, the rebuild can't keep pace with the breakdown.
Conclusion 2: EAAs Trigger a Rapid Muscle-Building Response
ISSN finding: Supplementation with free-form EAAs leads to a quick rise in peripheral EAA concentrations, which in turn stimulates muscle protein synthesis.
What this means after 40:
Free-form EAAs don't need to be digested like whole protein. They absorb directly into your bloodstream in approximately 15 minutes — causing a rapid spike in amino acid availability. This spike is the trigger that activates muscle protein synthesis. For anyone over 40 with a narrowing recovery window, speed of delivery matters. The faster the amino acids arrive, the stronger the signal.
Conclusion 3: EAA Supplementation Is Safe at High Doses
ISSN finding: The safe upper limit of EAA intake, without inborn metabolic disease, can easily accommodate additional supplementation.
What this means after 40:
One of the most common concerns: "Is it safe to take extra amino acids on top of my normal diet?" The ISSN's answer is clear — yes. The safe upper limit for EAA intake comfortably allows for supplementation above normal dietary protein. No kidney risk at supplemental doses. No toxicity concerns. Just peer-reviewed confirmation that adding EAAs to your routine is safe for healthy adults.
Conclusion 4: Small Doses Are Enough to Trigger Muscle Building
ISSN finding: At rest, stimulation of MPS occurs at relatively small dosages (1.5–3.0g) and seems to plateau at around 15–18g.
What this means after 40:
You don't need massive servings. The ISSN found that as little as 1.5 to 3 grams of EAAs can trigger muscle protein synthesis — that's less than a teaspoon. The response plateaus at around 15-18g, meaning there's a ceiling. More isn't always better — but enough is essential. Bare delivers the optimised dose: enough to trigger the signal, without unnecessary excess.
Conclusion 5: You Don't Need Non-Essential Amino Acids
ISSN finding: The MPS stimulation by EAAs does not require non-essential amino acids.
What this means after 40:
Your body makes 11 of the 20 amino acids on its own. Those are the "non-essential" ones — you don't need to supplement them. The 9 it can't make — the essential amino acids — are the ones that actually trigger the muscle-building response. This is why EAA supplements can deliver results in just 20 calories while protein shakes need 200+. You're only consuming what your body actually needs — nothing extra.
Conclusion 6: EAAs Stimulate MPS More Than Whole Protein
ISSN finding: Free-form EAA ingestion stimulates MPS more than an equivalent amount of intact protein.
What this means after 40:
This is the headline finding. Gram for gram, free-form EAAs trigger a stronger muscle protein synthesis response than the same amount of whole protein (like whey, casein, or food protein). The reason: EAAs are already in their free form — they don't need to be broken down. They arrive at your muscles intact, concentrated, and ready to work. For over-40 bodies dealing with anabolic resistance, this stronger signal is the difference between recovery that happens and recovery that stalls.
Conclusion 7: Multiple Doses Work — They Don't Cancel Out Your Meals
ISSN finding: Repeated EAA-induced MPS stimulation throughout the day does not diminish the anabolic effect of meal intake.
What this means after 40:
A common concern: "If I take EAAs, will my body stop responding to the protein in my meals?" The ISSN found the opposite. Repeated EAA doses throughout the day do not blunt the muscle-building response from your normal food. Morning dose, pre-workout dose, post-workout dose — each one triggers MPS independently, and your meals still work as normal. Every dose counts. None of them cancel each other out.
Conclusion 8: Aging Demands More Leucine
Although direct comparisons of various formulas have yet to be investigated, aging requires a greater proportion of leucine to overcome the reduced muscle sensitivity known as "anabolic resistance."
What this means after 40:
This is the conclusion that matters most for anyone over 40. Your muscles have become resistant to the normal signals that trigger repair — a phenomenon called anabolic resistance. To overcome it, you need a higher proportion of leucine — the amino acid that acts as the trigger for muscle protein synthesis. The same amount of leucine that worked at 30 falls short at 48. The threshold has risen. Bare delivers 3g leucine per serve — formulated specifically to cross that higher threshold.
Conclusion 9: EAAs Build Function Even Without Exercise
ISSN finding: Without exercise, EAA supplementation can enhance functional outcomes in anabolic-resistant populations.
What this means after 40:
Not everyone over 40 is running marathons or hitting the gym five days a week. Some are recovering from surgery. Some are dealing with reduced mobility. Some just want to stay strong enough to live independently. The ISSN confirmed that EAA supplementation can improve functional outcomes in aging populations even without exercise. You don't need to be an athlete to benefit. You just need the right amino acids.
Conclusion 10: Calorie Deficits Increase EAA Requirements
ISSN finding: EAA requirements rise in the face of caloric deficits. During caloric deficit, it's essential to meet whole-body EAA requirements to preserve anabolic sensitivity in skeletal muscle.
What this means after 40:
If you're trying to lose weight — and especially if you're over 40 — this conclusion is critical. When you eat less, your body doesn't just burn fat. It breaks down muscle for energy too. The ISSN found that EAA requirements actually increase during a calorie deficit — your body needs more of them to protect muscle, not less. Without adequate EAAs during a cut, you lose the very tissue that drives your metabolism. Bare delivers all 9 EAAs in just 20 calories — muscle protection that fits inside any calorie budget.
Bestseller
What the ISSN research means in practice:
EAAs are the primary driver of muscle protein synthesis — more effective than whole protein gram for gram. They absorb in minutes, not hours. They're safe to supplement daily. They work even without exercise. They're especially important after 40 when anabolic resistance makes recovery harder. And if you're in a calorie deficit, you need more of them — not less.
This isn't marketing. It's the official position of the world's leading sports nutrition research body.
What the ISSN research means in practice:
Every serve of Bare delivers all 9 essential amino acids in optimised ratios, enriched with 2g of leucine — the amount the research points to for crossing the anabolic resistance threshold after 40.
Source: Ferrando, A.A. et al. "International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance." Journal of the International Society of Sports Nutrition, 2023. DOI: 10.1080/15502783.2023.2263409
