IronDoes iron improve exercise performance?
Short answer
In women of childbearing age, it can. In a 2014 review, daily iron raised VO2max by 2.35 mL/kg/min in 18 trials in these women. It also lowered heart rate at a set workload by 4 beats per minute.[1] In a 2024 review of 13 studies in athletes, iron raised ferritin, mainly in those who started at 12 µg/L or lower. The effect on VO2max was small and not significant.[2]
A review of trials in adults with low iron but no anemia found no gain in measured physical capacity.[3] In female athletes with low ferritin, endurance improved by 2% to 20% with about 100 mg of iron a day, but 18 of the 23 studies had groups of 20 athletes or fewer.[4] More on fitness.
Sources (4)
- Iron supplementation benefits physical performance in women of reproductive age: a systematic review and meta-analysis. Pasricha SR, Low M, Thompson J, Farrell A, De-Regil LM J Nutr, 2014. PMID 24717371
- Effects of Oral Iron Supplementation on Blood Iron Status in Athletes: A Systematic Review, Meta-Analysis and Meta-Regression of Randomized Controlled Trials. Šmid AN, Golja P, Hadžić V, Abazović E, Drole K, Paravlic AH Sports Med, 2024. PMID 38407751
- Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. Houston BL, Hurrie D, Graham J, Perija B, Rimmer E, Rabbani R, et al. BMJ Open, 2018. PMID 29626044
- Iron deficiency, supplementation, and sports performance in female athletes: A systematic review. Pengelly M, Pumpa K, Pyne DB, Etxebarria N J Sport Health Sci, 2025. PMID 39536912
More about iron
What is iron?Which foods contain iron?How long does it take for iron supplements to work?What is iron used for?What are the signs of iron deficiency?Is iron safe?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.