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Learn · Proteins, Minerals & Muscle

CK (Creatine Kinase)

Measured in U/L

An enzyme released by working or damaged muscle. In lifters this is routinely high — and it explains most 'abnormal liver' results in athletic men.

What the numbers mean

These are the ranges BioForge works to. They are not the same as a lab's reference range, which is built from the general population rather than from people who feel well.

Low
<40
Optimal
50–200
High
>400 · Very high after hard · training

What moves CK (Creatine Kinase)

Driven almost entirely by recent training, especially heavy eccentric or novel work. Also raised by statins, creatine loading, and injections into muscle. Ask for it whenever your AST and ALT are both elevated — a high CK points to muscle, not liver.

Related markers in Proteins, Minerals & Muscle

This page is educational and is not medical advice. Ranges are general and do not account for your history, medications or symptoms — a single number never decides a protocol. Your results are interpreted by a licensed clinician alongside everything else about you. Back to the Learning Center

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Want to know where your numbers actually sit?

Every BioForge protocol starts from your own bloodwork. The first 15-to-30-minute call is free.

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