The Claim

In competitive swimmers, 7 days of creatine supplementation at 20 g/day does not significantly improve swimming performance, despite increasing urinary creatine excretion and body mass.

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.

Description
1 study reviewed
In plain English

In competitive swimmers, taking 20 grams of creatine daily for 7 days does not improve swimming performance, even though it increases body weight and creatine levels in urine.

See the scientific wording

In competitive swimmers, 7 days of creatine supplementation (20 g/day) does not significantly improve swimming performance, despite increasing urinary creatine excretion and body mass, suggesting that short-term creatine use may not enhance athletic performance in this population under standard training conditions.

Why this might work

When creatine is taken, it enters muscle cells and pulls in water, making the muscles hold more fluid. This increases body weight but does not make the muscles stronger or more efficient at producing energy. Even though the muscles have more creatine, the system does not use it faster during swimming, so performance does not improve.

Supported 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.

    Swimmers took creatine for a week, gained a little weight from water, and peed out more creatine—but they didn’t swim any faster. So, the study says creatine didn’t help them perform better.

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

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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