Beef Protein and iron & endurance

What 2 graded rows on beef protein agree on for iron & endurance, and where they differ. Counted side by side, never averaged.

Consensus finder Rows from the Beef Protein page, reviewed Oct 21, 2026 How it decides

What the rows agree on

Each block and row is one graded row from the Beef Protein page, with its PubMed record.

Supplement

Beef Protein Choose another

2 rows · 30 people

Split. 1 row found an improvement and 1 had mixed results.

Mixed

Improved

Each block is one evidence row, sized by how many people it enrolled, with its grade inside. Outlined: mixed results.

From the rows

The best-graded row, grade D, is a randomized trial of 24 people (2017) and found an improvement.

The rows run from 6 to 24 people, published from 2017 to 2021: 2 single studies.

1 improved · 1 mixed

Grade DBody composition and iron status in master-age triathletes · Improved
RCT · n 24 · 2017 · Male triathletes aged 35–60 (8 per group)
20 g/day · 10 weeks
Only beef reduced body mass and tended to preserve thigh muscle thickness. Ferritin rose with beef (117 to 150.5 ng/mL), more than with whey or carbohydrate.
Row on the Beef Protein page · PubMed 28910233 (opens PubMed)
Grade DMuscle size, hormones and blood markers in elite triathletes · Mixed
Crossover RCT · n 6 · 2021 · Male elite triathletes (Spanish national team)
25 g/day · 8 weeks per condition
Thigh cross-sectional area rose more with beef (3.02% difference, p = 0.028) and the testosterone-to-cortisol ratio was more favourable; there were no differences in body mass, skinfolds or iron, ferritin and other blood markers.
Row on the Beef Protein page · PubMed 32186977 (opens PubMed)