L-Isoleucine
Solid evidence for endurance. Not a miracle worker, but genuinely useful for the right person.
Verdict
7/10 Solid
Evidence
Grade B / 100+ Studies
The No-BS Summary
8 things. 60 seconds. Everything you need.
WHAT IT DOES
The endurance BCAA. Glucose into muscles, energy on tap.
DOES IT WORK?
7/10 Solid. Good pick. Essential amino acid. Helps muscles absorb glucose during exercise. Less anabolic than leucine but better for endurance.
HOW MUCH TO TAKE
3-6g daily, often as part of BCAA blend
COST
Budget-friendly. $20-35/month for quality brands.
FIRST 24 HOURS
Don't expect miracles on day one. It's building in your system.
AFTER A FEW WEEKS
Most people notice something by week 2-3.
SAFETY
Safe for most people. No red flags at normal doses.
HOW IT FEELS
Subtle. Maybe slightly better endurance during long sessions.
QUICK ANSWERS
+ 4 more questions
DOSE-RESPONSE CURVE
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