Myth-buster
Iron supplementation achieved the highest SUCRA ranking (56.54%) for lowering heart rate at altitude — but the benefit was not statistically significant in a systematic review of 329 people.
This contradicts the common belief that iron reliably improves heart rate during high-altitude exercise, but because this is among the first systematic reviews on the specific pairing and the dose wasn't specified, the evidence is still too preliminary to change any recommendations.
A network meta-analysis of 329 participants compared several dietary strategies for cardiopulmonary fitness at high altitude. Iron supplementation ranked best (SUCRA 56.54%) for reducing heart rate, but the result failed to reach statistical significance, meaning we can't be confident it wasn't due to chance. The same analysis also found no significant effect on hematocrit, and the iron dose was not specified, so the finding should be interpreted with caution.
Where this fits in the evidence
This is among the first studies we've indexed on Iron for Reduced Heart Rate — treat it as an early signal until more research accumulates.
The study
- Systematic Review
- n = 329
- 2025-11-04
- Frontiers in nutrition
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.