Research

Adherence

Dietary supplement use among fitness practitioners is highly prevalent (85.4%) and characterized by high heterogeneity in types and combinations, with no significant difference between gym users and instructors or between competitive and non-competitive participants.

If you are a gym user or instructor, you are part of a large group where 85% use supplements, often mixing various types like whey protein, BCAAs, and vitamins without clear guidelines. This self-directed approach can lead to inconsistent results and potential health risks from contaminants or interactions. To use supplements safely, seek guidance from a healthcare professional or sports nutritionist rather than relying solely on personal choice or advice from other gym-goers.

ModerateSupportsMEDIUM confidence
The results showed a high prevalence in the use of DSs in the population considered, with 85.4% of the participants declaring they used DSs, with high heterogeneity in the numbers and in the combinations used. No differences were found between gym instructors and gym users, or between participants involved and those not involved in competitions.
Massimiliano Mazzilli et al. · International Journal of Environmental Research and Public Health · 2021

Why this rating

Cross-sectional observational study with self-reported data; lacks causal inference and objective biomarker validation.

Source

The Use of Dietary Supplements in Fitness Practitioners: A Cross-Sectional Observation Study

Massimiliano Mazzilli et al. · International Journal of Environmental Research and Public Health · 2021

DOI 10.3390/ijerph18095005

cross_sectional · n=316Cited 23×
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DOI resolved against Crossref · corpus check 2026-06-10

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