The Claim

Creatine supplementation increases urinary creatine and creatinine excretion in competitive swimmers, indicating systemic absorption and metabolism, and over 50% of ingested creatine is retained, indicating significant tissue uptake.

Source: Effects of creatine supplementation on the performance and body composition of competitive swimmers.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
53score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

When competitive swimmers take creatine supplements, more creatine and creatinine appear in their urine, showing the body absorbs and processes it, and more than half of the creatine taken in stays in the body's tissues.

See the scientific wording

Creatine supplementation increases urinary creatine and creatinine excretion in competitive swimmers, indicating systemic absorption and metabolism, but over 50% of ingested creatine is retained, suggesting significant tissue uptake.

Why this might work

When creatine is swallowed, it enters the bloodstream and moves into muscle cells, where it is stored and pulls water along with it. The extra water increases muscle volume, and the creatine is used to help make energy quickly during intense activity. The body cannot store all of it, so the excess is filtered by the kidneys and excreted in urine as creatine and creatinine.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Effects of creatine supplementation on the performance and body composition of competitive swimmers.

    When swimmers took creatine, their urine had more creatine and creatinine, meaning their bodies absorbed it. Since they also gained weight (mostly water) but didn’t get more muscle, the creatine must have been stored somewhere in their bodies instead of all being peed out.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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