Iron for endurance athletes
Endurance — running, cycling, triathlon, swimming
Iron requirements can run substantially higher in endurance athletes — the figure in the mainstream position stand is an increase of up to about 70% over the ordinary recommended intake. That is a large adjustment, and it is the single biggest difference between an endurance athlete's nutrient targets and everybody else's.
Why this differs from the ordinary recommendation
Repeated footstrike causes a small amount of red cell breakdown, and distance running produces a lot of footstrikes.
Iron is lost in sweat and through the gut, and both losses rise with training volume.
Endurance training expands plasma volume, which can make blood tests look diluted — one reason iron status is something to measure properly rather than infer from how you feel.
Figures from the American College of Sports Medicine, Academy of Nutrition and Dietetics, and Dietitians of Canada — joint position stand, Nutrition and Athletic Performance (2016). Ranges are given at the conservative end — see the note on each number above.
Where this stops being useful
Iron is the one nutrient on this site where more is genuinely not better: excess iron accumulates and causes harm, and the symptoms of low iron overlap with ordinary training fatigue. Do not start an iron supplement on the strength of a food diary. Iron status is a blood test and a conversation with your doctor. This app raises a target in a diary and does nothing else.
Healthy Squirrel gives nutrition estimates, not medical advice.
Foods highest in iron (per 100 g)
| Food | per 100 g | % Daily Value |
|---|---|---|
| Goose, liver, raw | 31 mg | 170% |
| Duck, domesticated, liver, raw | 31 mg | 170% |
| Pork, fresh, variety meats and by-products, liver, raw | 23 mg | 129% |
| Seeds, sesame butter, paste | 19 mg | 107% |
| Thyme, fresh | 17 mg | 97% |
| Baking chocolate, unsweetened, squares | 17 mg | 97% |
| Soybeans, mature seeds, raw | 16 mg | 87% |
| Seeds, sesame seeds, whole, roasted and toasted | 15 mg | 82% |
| Mollusks, clam, mixed species, cooked, breaded and fried | 14 mg | 77% |
| Winged beans, mature seeds, raw | 13 mg | 75% |
| Chicken, liver, all classes, cooked, pan-fried | 13 mg | 72% |
| Archway Home Style Cookies, Reduced Fat Ginger Snaps | 13 mg | 70% |
Per 100 g from USDA FoodData Central, whole foods, highest first. In the app every amount scales to the serving you actually log.
More detail on this nutrient: foods highest in iron.
Track it without doing the arithmetic
Healthy Squirrel has a endurance training mode that sets these targets from your body weight, then fills them in as you log food — alongside every other vitamin and mineral. It's free, there's no account needed to start, and nothing is sold.
Open Healthy Squirrel, then choose Endurance under Training in Settings.
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