Research

Mixed

High protein intake (>236 g/day or >3.30 g/kg/day) combined with long-term supplementation (>1 year) significantly decreases glomerular filtration rate (GFR) and increases serum creatinine in CrossFit athletes compared to adequate intake without supplementation.

If you are a CrossFit athlete consuming more than 3.30 g of protein per kg of body weight daily, especially using supplements for over a year, monitor your kidney function (GFR and creatinine) regularly. High doses over long periods may reduce kidney filtration efficiency, even in healthy athletes.

ModerateSupportsMEDIUM confidence
Existieron disminuciones significativas (p<0.050) en la tasa de filtración glomerular con un alto consumo de 236.00 g/día y hubo un aumento significativo (p<0.050) de creatinina sérica en la suplementación durante más de un año, con una ingesta aumentada de 236.00 g/día, en comparación con aquellos con una ingesta adecuada sin suplementación.
Claudia González-González et al. · European Scientific Journal ESJ · 2023

Why this rating

Observational study with a small sample size (n=27) and short duration (4 months of data collection, though supplementation history was >1 year), lacking a control group of non-supplemented low-protein athletes for direct comparison of the intervention itself.

Source

Identificación de Factores Asociados a la Ingesta Proteica Incidentes Sobre Función Renal en Deportistas de CrossFit®

Claudia González-González et al. · European Scientific Journal ESJ · 2023

DOI 10.19044/esj.2023.v19n21p64

cross_sectional · n=27Cited 1×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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