Jeff Gaudette

Written by Jeff Gaudette


Iron Deficiency in Runners

Outside of training deficiencies, low iron levels in runners is one of the most common reasons for poor results during workouts and races.

Recent research indicates that almost 56% percent of joggers and competitive runners suffer from an iron deficiency that severely hampers performance. By closely monitoring iron intake and supplementing if needed, you can quickly boost performance and prevent lulls in your training.

Symptoms of Iron Deficiency in Runners

Determining if you have an iron deficiency can be somewhat difficult if you’re a runner. The main symptom of low iron levels is fatigue and a slight shortness of breath. You can appreciate the dilemma here if you’re a runner – you’re always tired after a workout and shortness of breath defines our preferred mode of transportation.

If you are worried that you might be iron deficient, you should schedule an appointment with your physician for a blood test. It’s a simple test that most doctors would be willing to provide if you tell them you’re running a lot of miles and feeling more fatigued than usual. Even if you are not iron deficient, you can establish a good baseline for your iron levels, which could help you identify an iron problem down the road.

The major results of interest to runners are: hemoglobin (Hg), hematocrit (Hct), iron (Fe), total iron binding capacity (TIBC), and ferritin. In anemia, your hemoglobin and hematocrit, which are a measure of your red blood cell count, are low. In iron deficiency, your iron is low, your total iron binding capacity is high (meaning there is lots of extra room to bind more iron), and your ferritin (a measure of your iron stores) is low.  In my experience coaching elite runners, a ferritin level less than 30 ng/ml in women and less than 40 ng/ml in men is often enough to reduce performance and impact your running.

Why is Iron Important for Runners

Red blood cells, which contain hemoglobin (an iron-containing protein), transport oxygen to your working muscles when you run. If you have low iron levels, you will generate fewer red blood cells and your hemoglobin levels will decline. Therefore, less oxygen will be transported to your muscles, and running performance will suffer.

How Runners Lose Iron

Runners lose more iron than non-runners for a multitude of reasons.

Through your feet – First, a process called foot strike hemolysis occurs in runners, especially those who run high mileage. Foot strike hemolysis is a process where red blood cells are damaged when the foot hits the ground, thus reducing your hemoglobin levels.

Through sweat – Iron is lost through sweating. While the amount of iron loss isn’t staggering, for a runner working out in hot and humid conditions, the losses can easily add up.

Through the intestines – Loss of iron through the GI tract (primarily the stomach or large intestine) is a problem for some athletes. Iron loss through the GI tract is fairly minor, but there may be a cumulative effect over months of running that leads to iron deficiency.

Female runners – Finally, female runners have an especially difficult time maintaining proper iron levels since they also lose iron during menstruation.

How to Supplement

As you can see, the cards are stacked against you as a runner when it comes to maintaining your iron levels. Therefore, it is important that you consciously monitor your iron intake through your diet and with supplements, if you already have low levels.

Iron rich foodsiron rich foods

Good food sources of iron include: lean meat, oysters, egg yolk, dark green leafy vegetables, legumes, dried fruit, and whole grain or enriched cereals and bread. If you are worried about your iron levels, avoid drinking coffee, milk, or tea with iron-rich meals, as calcium inhibits iron absorption. In addition, you should drink vitamin C with your iron rich foods since vitamin C aids in absorption.


I suggest most runners be on an iron supplement unless their iron levels have tested high in the past.

  • When you go to buy an iron supplement, make sure it’s in the form of ferrous sulfate. Usually, you can find iron at a health store like vitamin world or a GNC. You can take iron in a pill or liquid form, whichever works best for you. Pills are often easier to find, but liquid absorbs better.
  • Like when you’re eating, avoid calcium an hour before and an hour after taking your iron. Likewise, take with vitamin B (a pill or orange juice) and a B-complex supplement to aid absorption.
  • I suggest taking your supplement before bed. Iron supplements can sometimes cause minor stomach issues and gas. If you take them at night, it probably won’t bother you. If your stomach does bother you, taking ferrous gluconate rather than ferrous sulfate can be easier on your stomach. Iron supplements can also cause constipation, so you could consider a stool softener if needed.
  • If you’re just looking to maintain your iron levels, supplement with 30mg of elemental iron. If you are iron deficient, supplement with 60mg of elemental iron.

By paying attention to your iron levels, getting tested if you think you may be low, and increasing your iron intake through diet or supplements, you can avoid lulls in your training and boost performance.

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106 Responses on “Iron Deficiency in Runners

    • Yes, cast iron cookware will leech iron into your foods. Good suggestion, Stephen. While cast iron cookware won’t provide you with a ton of iron, it can help boost your intake up a little bit, especially for vegan runners who don’t eat red meat. Thanks for the suggestion!

  1. THANK YOU, THANK YOU, THANK YOU for this post!!!!! I’ve been trying to find answers about iron deficiency for awhile. I’ve been tested and had super low iron levels. I took a supplement prescribed by my doctor but it wreaked havoc on my stomach. It’s important so now I know how to make smarter choices. I appreciated this article so much!

    • I am very happy the article helped you so much, Samantha. If you have any other questions about iron or have trouble finding a good supplement, don’t hesitate to let me know. Happy running!

  2. Hi Melanie this is a great article. What are your thoughts on taking black strap molasses to get your iron? I’ve heard it’s more absorbable than supplements but I don’t know. And are there any potential side effects from taking iron supplements when you don’t need it?

    • You’re welcome, Daniel.

      I’ve never heard of black stap molasses in general. After looking it up, it does appear to be a good source of iron, but it also has a lot of calcium, which hinders absorbtion. It’s certainly a good natural way to increase iron stores, but I don’t know exactly how effective it is.

      As for the potetial side effects, taking too much iron can be toxic. The main synptoms would be nausea, vommiting, and major constipation. However, it does take a lot of iron to over supplement and if you stick with the guidelines provided above, you shouldn’t have any issues.

      Good luck!

  3. I have been having a huge struggle training for my marathon in June. I just got my ferritin checked, it was an 8. Not one of my long runs have been good, they are a fight to finish. I’ve read so much information and learned so much, but I can’t seem to find anything about weather or not I should continue to train and if it’s realistic to have a good marathon come June.
    I am taking an iron supplements, I have surgery in mid May to correct my long and heavy menstrual cycles. I’m a fighter so it’s hard for me to know whether I should continue to push training or not. I know it takes 4 months to completely rebuild iron stores, does that mean that you cannot (should not) run long distance until then?
    I would be so grateful for any advise or help. Thank you!

    • Sorry to hear your training has been such a struggle, Pam. With a ferritin of 8, I don’t recommend you continue to train hard and push for the marathon. You’re correct, it takes about 4 months of heavy and focused supplementation to get the needle moving when it comes to ferritin and hemoglobin levels. Therefore, I think you’ll continue to struggle with the training, which won’t result in you having a performance you will be happy with. In addition, training hard is at odds with building iron stores, so it’s going to take longer for you to make significant gains in your blood profile. In my opinion, it would be better to scale your training back to a maintenance level that will allow you to keep fit, but won’t interfere with iron absorption. While it means you’ll miss your short-term goal, it will allow you to comeback for a great race faster. Best of luck and I hope that helps.

      • Thank you so much for your response. I appreciate your advice taking time to explain. It will take some time to absorb but, deep inside I know this is the right decision in the long run. I kept thinking I’d turn a corner in how I felt but rest and maintenance will win out. Thank you 100 x over!

    • Yes, this information pertains to teens as well. If you’re a female teenage runner, it’s important you eat healthy sources of iron to keep your stores up. Many HS and college female athletes suffer from anemia and low iron levels.

  4. Very informative article. I never paid attention to my iron levels. After reading this article I will get a blood test done and start using iron supplements.

  5. I have just read your article and now everything makes sense. For the last six months I have struggle to run distances that where absolutely no problem to me a year ago! At Easter I had routine blood tests that showed that my iron was low. It was actually only mid June before I felt that I could increase my runs and I feel stronger by the day. Thanks for putting some meat on the bones.

  6. Thank you SO much for this awesome article! Sorry, I have so many questions…I just got tested last week and found out I have a ferritin level of 10.7. Given my low level, do you suggest taking more than the 60mg of iron supplement (that was recommended above)? How mg can I take without overdosing on iron? I read online iron injections are one treatment…is this the fastest way to increase ferritin levels? I started taking the supplements in the form of Hydrolyzed Protein Chelate (but with no direction, at <60mg/day) and have already started feeling better. I took a few days off and have started running easy, but is it ok to resume my training and racing schedule despite being iron deficient? Dying to get back on the road here! Any guidance would be greatly appreciated!!

    • Hi Eva, I am glad you enjoyed the article and had your blood work tested. To answer your iron related questions, I would take two 60mg supplements of ferrous sulfate per day (one in the morning, one at night). You can take it in pill or liquid form (liquid is absorbed easier and should be taken with orange juice to prevent teeth staining). The other forms of iron are not readily absorbed. Iron injections are really only for individuals who are severely anemic (which you are not) and who cannot take an oral supplement.

      As for training, I would defer to coach Blake as I think he has a better long-term view of your training and racing plans. He is very experienced working with runners who have iron issues and will make sure your training coincides with getting your levels up.

      Hope that helps!

      • I am an RN and working in hematology, so quite frequently see people with low iron levels. It is important to also have an iron saturation test done as well and TIBC. These tests will more adequately determine the level of iron deficiency. I have seen people with a ferritin level of 30 need to have IV iron, depending on the outcome of the aforementioned lab tests.

    • Hi Eva –

      I’m glad the article helped and I see that Coach Melanie has already helped with a great response.

      As far as training goes, the real question that any runner in your position wants to know is – how long until I feel like myself again… Unfortunately, there is no formula that applies universally. I’ve read that it takes three months to return to normal ferritin and activity levels but with rest and supplementation I think that two weeks is a very realistic expectation. Obviously that’s a wide range but I expect for you to be on the low end of that.

      I’m familiar with your circumstances and your training so I’m confident in saying that you can do a workout this week and you’ll be feeling fit and ready in time for your marathon training to start in August.

      Talk to you soon!

  7. Thank you for the article, Coach Melanie!

    I never thought to seek so many parameters for iron levels. I am a first-year graduate student getting immunizations for school on Monday, so I will ask if they can perform this blood test for me!

    Unfortunately, almost all the high-iron foods you mentioned I do not enjoy. This is with the exception of fortified cereal (I do eat Total Cereal), but I have not considered until now that eating it with milk (calcium) would decrease the iron absorption!

    I thought of a few questions:

    1) What would be a good substitute for milk that I could use so that the iron could be absorbed readily by Total Cereal? I might have to resort to eating the cereal plain (from a Ziploc bag or something!)

    2) I do like to sprinkle Lemon Pepper on my vegetables. Do you think if I sprinkle this onto Spinach and Tomatoes, that it could have the same effect of increased absorption that you said Vitamin B/C can provide?

    3) I tend to lean toward “natural” intake of nutrients and vitamins. However, I am still keen to read your advice regarding supplements. What are potential dangers of liquid iron supplements? In your article and comments, you mentioned teeth staining, “stomach problems”, and iron overdose leading to vomiting, constipation, and fatigue. What are the long-term effects of iron overdoes, and what are the chances of iron poisoning? Also, could you elaborate more on what “stomach problems” could occur?

    4) I am considering iron supplementation. You suggest supplementation in the form of “ferrous sulfate”. Will this be clearly labeled, and what other forms of supplementation are there (so that I can know to avoid those other forms).

    5) Does your suggestion for liquid ferrous sulfate iron supplementation come not only from scientific/physiological knowledge, but also from application? That is, do you personally, or do you personally know other successful runners who, follow this suggestion?

    Thanks again!

    • Hi Lin,

      I am glad the article helped so much. Lot’s of tough questions, I’ll do my best:

      1. Soy milk and rice milk with have less calcium. However, fortified cereals are not a good choice for iron. For example, iron fortified cereals can contain actual iron filings, which is a far cry from the bioavailable iron you get from iron-rich vegetables like spinach.

      2. I am not sure why it would? I don’t have an ingredients label, but does lemon pepper have B-complex or Vitamin C?

      3. Stomach problems would be generally upset stomach and constipation. Iron over-dosing is the most common issue, but if you follow the guidelines in the article, that shouldn’t be a problem. Iron-over dosing is something that is far too complex to cover in a comment. I will write an article about it.

      4. Yes, it will be clearly labeled on the package or in the ingredients list. the other common forms are iron fumarate or iron chelate.

      5. Yes, these guidelines are both from my experience as a physician and from my time spent as an elite runner.

      Best of luck!

  8. Thanks so much for this information. My son is a X-country/Track coach and we’ve discovered that quite a few of his runners are quite likely anemic. The one runner who was tested for ferritin serum came back with a count of 4!! It’s a wonder he’s walking around let alone running. I’m a midwife and will be helping parents get the blood work they need to test their own children and then will recommend nutritional sources as well as supplemental iron to build their kids up. One thing that I would recommend that you NOT recommend is ferrous sulfate. It’s very toxic and the cause of digestive upsets and constipation. There are many natural herbal iron tinctures and liquids that are a much better source of easily absorbed iron. Thanks for all the tips on how and when to take it.

    • Thanks for commenting, Judith and I am glad the article helped you and your son. However, ferrous sulfate is NOT toxic (not sure where you’re getting that info) when taken in the recommended dose. More importantly, it is the most readily absorbed type of iron, which is why it is the number one doctor recommended iron supplement to treat iron deficiency.

  9. Hi,

    I am due to run a marathon in 10 days and have just found out that I have a low iron level. Having not taken iron tablets before, is it worth beginning the supplements now as I know it takes 3 months to really increase your iron level properly? I don’t want any side effects to affect my marathon?


    • Hmm, that’s actually a tough question, Charlotte. I think I would do this – take a liquid iron supplement for the next 6-7 days. It should upset your stomach too much and you’re not training hard, so even if it does bother you a bit during a run, it won’t compromise and important workout. Then, about 4 days from the race, stop taking the supplement to allow everything to get back to normal. this should get your iron levels up a bit while leaving your stomach fine for race day. Hope that helps and good luck!

  10. I have a half marathon in 5 days and recently found out (through a blood donation) that my Ferretin level in 10, which explains so problems 🙂 What can I do to help myself out?? I really still want to run!!

    • Sorry to hear about the low levels, Jen. You can still run, just be aware that you might not have your best performance. You can start supplementing right away with the liquid iron and adding more iron-rich foods to your diet. It will take about three weeks to see changes in your blood profile, but the sooner you get started, the quicker you’ll start feeling better.

  11. Hi there,
    This article is great and the Q+A at the end is extremely useful. I’ve had low iron in the past and think I’m suffering the same thing again after I really dragged in a marathon last week, coming in 25minutes over my predicted race time for no good reason. I’m waiting on my blood results but expecting a low ferritin. I’m supposed to be running a 40mile race (my first) in 4 months time and training starts now, pretty much. Most weekends I’ll be covering upwards of 26miles over 2days, plus running midweek as well. Is this a really daft idea? I’ve already run two marathons and a half marathon this year but I really don’t want to pull out of the ultra as I’ve told everyone I’m doing it!

    • Sorry to hear about your iron issues, Kitty. Hopefully, you’ll be able to get your numbers up quickly and glad the info helped.

      If you’re training for an Ultra, I would say every other weekend should be a back-to-back long run. That is how I coach for the Ultra. Just make sure your blood work looks good!

  12. Hi. I have a question regarding supplementing with iron. I have run 6 marathons (so I know what the training is like) and am currently in training for another marathon in late June. Two years ago I was found to be “slightly” anemic (hemoglobin level was low) and at that point I was COMPLETELY fatigued all the time with significant hair loss and brittle nails. Per doctor instructions I supplemented with iron for several months and felt much better.

    Fast forward to now. I’m feeling fatigued again with more hair loss and brittle nails. I was feeling quite happy that I seemed to have caught it earlier this time and have just had an appointment with the doctor. I got my bloodwork results back and my hemoglobin was in the normal range but my ferritin was 14. This doctor told me NOT to take an iron supplement (we have moved since my anemia 2 years ago and have a new physician now). I have a follow-up appointment with her next week where I will discuss this with her further but I have actually been taking an iron supplement for 3 weeks already (because I felt I knew the symptoms and also knew that it takes quite some time to get back to normal). I had told the doctor that at my appointment and she told me to stop taking them. Considering my poor running performance, fatigue and the fact that she and I are seriously discussing that I get a uterine ablation to control my extremely heavy periods….is there any harm in my continuing to supplement with iron? Just FYI she had my thyroid function checked as well and everything came back normal there.

    Again running off past experience from training cycles I cannot pinpoint another reason (I’m sleeping plenty, eating very well, my weight is stable to what it has been for my other training cycles) for my fatigue and poor running and everything I have read indicates that a ferritin level of 14 is too low for an endurance runner.

    Thank you for your time.

    • Hi Jaci,

      Sorry you’re having issues. While I agree that 14 ferritin is low and should be supplemented, I would still wait to listen to your doctor and/or get a second opinion. Ferritin guidelines are different for runners and “normal” people, so while 14 might be within normal range, it’s perhaps not what your number should be. I would ask if that us how he/she is basing their decision to not supplement. If so, seek the consultation of a doctor more familiar with runners. However, it’s possible he/she has another reason, based on medical data I don’t know, about the reason for not supplementing. Hope that helps.

      • Thank you for your reply. I followed up with my doctor and apparently the person who called with my lab results gave me the wrong information when telling me not to supplement. My doctor DOES want me to continue with 325mg ferrous sulfate tablets per day for 3 months and then get bloodwork rechecked. She said a ferritin level of 14 is quite low considering I’d already been supplementing for almost 3 weeks prior to my bloodwork.

        Now to get the heavy periods taken care of so hopefully this low iron issue can be resolved for good.

        Thankfully I’m starting to feel a bit better AND the weather is finally supposed to take a turn toward spring-like. Hoping that means I can get out and actually enjoy running again.

        • Make sure to get follow up tests after you start taking supplements to make sure your ferritin—and not just your RBC and hemoglobin—is improving. My RBC and hemoglobin have been routinely stellar while my ferritin is at rock-bottom.

          I’ve had iron deficiency and iron-deficiency anemia off and on all my life but never had adequate treatment for it.

          For some reason I don’t absorb oral iron well and I can’t maintain ferritin levels. After taking a double-dose of oral iron for over a year, my ferritin went only from 5 to 9. My GP’s response was “Well, it happens.” It destroyed my training for the 2011 NYC Marathon and caused me to give up training for 2013.

          I finally went to see a hematologist (who ran loads of tests to make sure there were no underlying issues) and started getting IV iron infusions. For the first time in my life—and I’m 51—I feel really good day to day. I have a level of energy I’ve never had in my life. My mood has lifted, my running has improved, and training is no longer torture.

  13. I have a high school daughter who runs xc and track. How do you balance getting enough calcium and iron? Both being an issue with teen girls who run. I was having her take a calcium supplement with her meals, but now I’m not so sure seeing that the calcium may inhibit the iron absorption.

    • Great question. Just separate the times you take both supplements. have calcium in the morning and then iron at night. That should be prevent any potential interaction with the two.

  14. Hello,

    Thank you so much in advance for your help. I found out that my iron level is not measurable (less than 5), but I am planning to run a 50K May 25th. I was already taking 150 mg Feramax, and my doctor has told me to double up on it. I have been doing that for about a week already. I am trying to eat iron-rich foods, e.g. liver. I am going to start taking the iron at night so my coffee in the morning won’t interfere with absorption. My question is whether you think that will be sufficient to run on race day?

    I really appreciate anything you can tell me.

    • Hard to say since iron levels don’t increase at a predictable rate. However, your numbers probably won’t be in the normal range by race day judging by your currently very low numbers. Does that mean you can’t race? No. But, I would definitely be prepared to slow your pace down and run less for time and more for fun.

  15. I have read all the comments with interest as I too was diagnosed with anaemia 6 weeks ago while training for a marathon in July. My ferritin was 5 and Hb 93…I was running fatigued and slow wandering why I was not improving. Since taking iron supplements it feels like I am on performance enhancing drugs. Initially I took 270mg Ferrous sulphate twice a day (with no side effects). After about 2 weeks my performance improved dramatically…I never thought I would ever run sub 5min k’s and now can do it easy. Overall my times have improved by at least 30sec/k. Hope this encourages someone :-). (I was also told not to run longer for 2hrs until my Hb came back up as I was at risk for cardiac failure. My Hb is now 134 and Ferritin 18.)

  16. Pingback: Strong runs, low iron levels, and a tuna noodle salad | Movable Mom

  17. I wanted to know if you could recommend a product to use? There are so many out there and its becoming a bit confusing. My doctor told me I had a ferratin level of 10. He just said its low and kind of made it like I could supplement if I want?! I’m pulling myself or shall I say dragging myself through every run and I can’t understand why so much of the struggle and so little gain….I’m thinking this may be my biggest problem.

  18. Coach Melanie:

    I have been diagnosed with low iron, ferritin level of 10. I am a male runner, late 60’s. I just started the iron supplements and my doctor advised scaling back my running for the time being. My question is should I still do track workouts but at a slower pace and less volume. If yes what type of track workout would you recommend. In the past, I would do around 3 miles worth of intervals (i.e., 4 times 1200 meters with a jog lap recovery.) Thanks.


  19. Hello ~
    My daughter is a cross country runner. At the high school level. In March she had blood work and it indicated she was not anemic but her ferritin level was 19. She was just coming back from an injury so her training wasn’t extreme. She is back to running at 100 % . She is kinda dragging all of a sudden. Fatigue , breathing issues etc. If it is low ferritn have you heard of ProFerrin hemme iron supplements ? Just wondering if they are better ? I can crush them as she can not swallow pills.
    Thanks so much !!

    • Sorry to hear about your daughter’s iron. I have never heard of ProFerrin – I think it’s just a brand name. As long as the iron is ferrous sulfate, it will work fine.

    • In response to coach Jeff’s above post about Proferrin I have recently learned how unique and different this Iron supplement is. Proferrin is a Heme Iron polypeptide and is the only heme iron supplement in Canada. Because it Heme the body absorbs it better through it’s specific Heme receptors. These would be the HCP1 receptors. After reading some studies on Proferrin I have learned that it provides higher iron absorption and much lower incidences of GI side effect. In addition I have learned that it has no food affect where some of the other iron’s such as Ferrous gluconate, Sulfate, and polysaccharide do. From what I have learned I think they Proferrin is better and vastly different than all the other iron supplements. This is backed up with the amount of scientific info and the greater amount of Iron absorption, I believe Proferrin Heme Iron supplements are the way to go.

  20. Hello,

    Can you comment on whether it’s in anyway dangerous to try and run a marathon on low ferritin and hemoglobin levels? My ferritin came back at 5 and hemoglobin 108, I’m supposed to run my 10th marathon in 12 weeks? I have just started supplementing this week. But I lost my base training the last 5 months due to my first flare of polymyalgia rheumatic (cause unknown). I’m just starting to run again now, 20 miles total this week. Should I pull out of the maratthon or is it reasonable to run/walk to finish? Any help is appreciated, since my doctors are not familiar with sports and anemia.

    • I wouldn’t recommend it. Note the response to the same question in the comments above: With a ferritin of 8, I don’t recommend you continue to train hard and push for the marathon. You’re correct, it takes about 4 months of heavy and focused supplementation to get the needle moving when it comes to ferritin and hemoglobin levels. Therefore, I think you’ll continue to struggle with the training, which won’t result in you having a performance you will be happy with. In addition, training hard is at odds with building iron stores, so it’s going to take longer for you to make significant gains in your blood profile. In my opinion, it would be better to scale your training back to a maintenance level that will allow you to keep fit, but won’t interfere with iron absorption. While it means you’ll miss your short-term goal, it will allow you to comeback for a great race faster. Best of luck and I hope that helps.

  21. Just curious why ferrous sulfate is preferred and what experience you have had with ferrous succinate (Integrative Therapeutics Iron Complex)? My son ran xc in high school. His performance deteriorated and he fainted three times. After extensive cardiac and other testing, the doctors all said that he was dehydrated (I knew that wasn’t the problem). I did some research online and learned about low ferritin. Sure enough, when tested, his level was 12. He started with ferrous sulfate and had terrible stomach issues. We saw a sports nutritionist who started him on the Iron Complex. He has been supplementing for 10 months and has just reached a ferritin level of 64. He is just starting college xc and the doctor said that now that his level is over 50 he could stop the iron supplement and start a multivitamin with iron. I’m interested in your thoughts on both this type of iron as well as the implications of stopping now that he is in very intense college xc training?

  22. Thanks for the article! I was just wondering if cold and numb hands and feet could be a symptom? I commonly have this and fatigue and dizziness. My blood pressure is also measured low. Thanks for the help!

  23. hi, my 16 year old daughter who is a runner recently had her iron tested. Her Iron came back 231 and her ferratin 30. Her doctor told me she should stop taking iron supplements because her overall iron was too high.
    Her ferratin is only 30 and she runs year round. It is up from 19 last year. I’d like to keep it status quo. What does it mean when the iron serum is high?

  24. I’ve struggled with low ferritin for quite some time now however whenever I take iron supplements I become extremely fatigued. A bit ironic I know but I’ve tried multiple brands and lower levels of potency and nothing seems to help. Besides getting a lot of iron in my diet is there anything else I can do about this? Would a liquid iron be good to try?

  25. I’m a runner, training for a marathon followed by a 50K, recently diagnosed with iron deficiency anemia (Hgb 8.9, ferritin 6). At my PA’s recommendation, I’ve been taking Floridex herbal liquid iron supplement and it has, remarkably, NOT caused the usual GI problems I’ve had with other iron supplements (constipation, black stools, upset stomach). It’s not cheap, but it’s working well for me. (I don’t work for the company or anything, I just want to fix this stupid anemia).

  26. I’m a marathon runner. All last year my running was awful: I couldn’t even finish a 5k race without walking a few times! Occasionally, I’d have a decent race but that was the exception rather than the rule. When I got my physical, Dr saw my iron was low (9) but wasn’t worried about it because hemoblobin was ok. Later I read that low iron can result in problems for endurance runners. A year earlier my iron was at 27. After talking to Dr. about this, he put me on ferrous sulfate. After a couple of months, my running was much improved and my ferritin was up to 22 (which is at the low end of the recommended level). Dr was satisfied. But I wonder, if I should continue to try to get ferritin level at least to 27? I’ve continued taking supplement (26 mg ferrous gluconate/day). What would you recommend?

  27. By”low dose”, do you mean I should just continue the daily 27 mg ferrous gluconate I’m currently taking. I guess I’m wondering whether having reached a ferritin level of 22, I should just try to “maintain” that level or should I still be trying to increase my ferritin by possibly taking two 27 mg pills/day? (my ferritin level was at 27 a year ago and a couple of years ago it was at about 45).

    Thanks for your help,


  28. My daughter is a Senior in HS, running cross country. She had blood work done last week that showed her Ferritin levels at 3. Should she continue to train and race? or cut back? She is really disappointed as she was the team’s no.1 runner last year…
    Any help is appreciated-

    • I would have her rest up for a week or two (or at least just run easy – no workouts or races) while she begins her iron supplement. I’d also highly suggest she see a doctor to find out why her iron levels are so low.

  29. Thanks for trying to answer Q, understand (Jeff) you’re not a doc, all advice is use at your own risk etc.. 🙂

    47 y.o. female distance runner. Just had bloodwork done, “iron” levels ok but ferritin is 22 (down from 49 last yr when I wasn’t training as much but wasn’t any less tired). Had been doing heavy training for marathon and was going GREAT till tendon injury 1 month ago, rehabbing and coming back now.

    My doc – who doesn’t treat many athletes – wasn’t concerned about ferritin (tho my b12 is lower than she wants and she wants me to supplement that) but I am! (also, my MCV is high, so w/ ferritin & b12 low, think it’s pre-anemia warning). She said I could try a low dose of iron if I wanted, her office carries IronPlex which is ferrous bis-glycinate I think, 27mg, w/ ascorbic acid & B. (any comment on that product?)

    I have a lot of GI issues – ulcers, on PPIs – that could be causing problems absorbing iron and b12 tho I eat plenty of meat. (also have problems absorbing critical calcium for GI and other reasons and have to keep iron/calcium timing away from other meds). Not looking for more GI irritation or constipation, that’s for sure!

    Interested in some of the effects of low iron as read on the Proferrin (heme iron polypeptide, 12mg elemental per tab) site “Any athlete with low ferritin levels may suffer from exhaustion, declining performance, heavy legs, tight muscles and increased risk of injury.”
    Wondering if that’s what I ran into (tight muscles, injury), plus some typical low energy I put down to heavier training and age.

    I’m planning to start taking iron – any suggestions on product or dose? Every other day to start? Or daily? How much? I could start w/ the Proferrin which is lower dose and maybe easier, but how long to know if I’m getting an effect?

    Anyone have experience taking Proferrin aside from the one poster above? Or IronPlex?

    All input, suggestions much appreciated!

  30. So what if the only time I have an issue is race day. I don’t need iron for daily life or training runs — 7 or 12 miles each, twice a week. But at about 18 trail miles, especially with lots of vertical I start to feel the deficiency (in the form of almost-cramping lower leg spasms). Is there a supplement or food I can use to just gear up for race day? Thanks!

  31. We have come to a frustrating point with our daughter who runs HS XC (2nd year). She cannot keep her Iron or ferritin levels up no matter what we do. We have spent thousands of out of pocket $ running every kind of test. She has no health issues. The HS she runs with is a large school with a very rigorous training schedule. I’m afraid that because of her body make up, and the hard practices; she is at a point of having to quit. She has had her ferritin as low as 3. She wants to run so bad, but has only managed to run 3 races in two years so far. Anyone else have a situation like this? She would probably be OK running for a smaller HS with a less rigorous training schedule; unfortunately her coach does not cater to special cases.

  32. Hi Coach! I’m a long time runner and often feel fatigued by mid day. This article has brought up some questions I should asked my doctor about. Do you know anything about heme verses non-heme iron? I see you have answered some questions about ‘low dose’ iron and know often ‘low dose iron’ is a different type of iron completeIy (heme). I read that heme iron supplements absorb better than non-heme so thats why the doses are lower. Your body gets more iron by taking a lower dose. I also read some of the GI side effects are lower since there isn’t as much build up in your body. Do you know any more about this?

  33. Hi, great article, loved it! Ive been out of form and out of breath past 3-4 days. I ran only 11k today at an easy pace but it was a struggle. Strange. Because I’ve been doing pretty fast pace runs and a longer run of 20k last week and felt fine. So is it exhaustion or do I need to check for iron deficiency or eat more proteins? my BP is on the lower side and so is blood sugar…. haemoglobin is at 13, don’t know my ferritin levels. Yeah, just finished my period. Running my first HM on 15th Dec and this is worrying me.

  34. Lots of advice on taking Ferrous Sulfate Supplements when needed but no advice on a safe dosage. Currently my daughter is taking 65MG of Iron (325 mg Ferrous Sulfate) two times a day and has had no side effects and is running much better. Can I assume we are being safe here and do not run risk of high iron levels? Thank You

    • It’s in the article: “If you are iron deficient, supplement with 60mg of elemental iron”. So, you’re ok but she shouldn’t be on this much for more than a month or two. If she’s still iron deficient after this she should see a doctor.

  35. Interesting article, thanks.
    You mention avoiding tea and coffee as this inhibits absorption of iron, Is this only due to calcium in the milk or is there something else in tea and coffee that is to blame (tannins, caffeine etc)
    I take my drinks without milk, hence the question.

  36. Hi my son aged 15 is a mid distance track runner (national standard) and cross country runner, since August he has been struggling with the longer distances and we got his blood checked in December, we were told his ferritin was slightly low, vit d was low and liver function was slightly high. He was told to take multi vitamins, the dr said he wasn’t concerned and to get retested in 6 weeks. we just got his blood retested and the nurse told me his results from the previous test his ferritin was 22 , she said normal is between 30 and 300, so is 22 considered to only be slightly low.? Should he have been told to take feriglobum? Or similar supplement, his coach said low in most people would not cause to many problems but in athletes it should be taken more seriously. I get results tomorrow and when I see the doc I would like to have a bit more of an insight on this, can you help? Any info/advice would be much appreciated. Incidentally he has been improving with his running in the last 2 weeks. Thank you!

  37. I am a 60 year old male that has been running for the last 35 years. I have run numerous sub 3 hour marathons prior to turning 40 so my fitness level is above average. Over the last few years I have begun to experience shortness of breath and dizziness while running up hills and even walking up stairs. I have seen cardiologists, and pulmonary specialists about this problem and they have not been able to find anything wrong with my heart or lungs.

    Your article on iron deficiency intrigued me because the cardiologist felt my problem could be attributed to a number of possibilities including hydration and glycemia. My general physician disagrees. He feels the problem is attributed to old age and the increase in weight over the last few years. I have gained about 30 pounds over the last few years, due to an inactive period when I was diagnosed with RA. My RA physician has noted that my iron levels were getting low and she has been monitoring them. Any thoughts.

  38. Hi,
    Great article! It was perfect timing for me to find it! I have struggled with low iron since I was a teenager (now 32), however, the symptoms became more apparent when I started taking running more seriously and training for my first half. On all my runs (more so over 5 miles), I have ‘tummy issues’ that require me to stop for a bathroom break. This usually happens a few times each run. This has caused me to fear any race situation and become reliant on the treadmill. Just wondering your thoughts on if this could be related to my low iron. This problem only occurs when I run and I do not have any other tummy issues outside of that! Any advice would be greatly appreciated! I would love to be able to start competing!

  39. I’ve had anemia for years and it’s just become something I’ve learned to live with. My levels have ranged from 7.5 to 12.5 over the last decade (and possibly higher but I’ve not been tested in the last 4 years – I got fed up of people sticking needles in me).

    However, over the last few years I have completely stopped taking iron pills. I have yet to find one that doesn’t make me feel awful (yes, I’ve tried almost every brand out there, prescription and non-prescription). The one that bothered me the least was Vital Code, as the ingredient list was a load of vegetables rather than a ferrous variant. I also took it with chlorophyll as I read a paper that said when the two were taken together the chlorophyll boosted red blood cell production.

    But these days I don’t take any supplements. I only manage my anemia through diet. I eat a lot of liver pate (yes, I know it’s gross to handle raw livers… but it has to be done) and I avoid eating iron rich foods in conjunction with foods that I know inhibit iron absorption (tea, coffee, red wine (the tannins), dairy, eggs and whole grains). In fact, as I have Celiac disease, I don’t eat any grains whatsoever (I highly recommend Elena’s Pantry, Paleo Mom and Mickey Trescott for substitute recipes).

    I now feel so much better and full of beans that I’m ready to start contemplating taking up serious cardio exercise again (running). I haven’t felt up to this in over ten years, so clearly diet matters (a LOT).

    If the running kills me I’ll update you, but as to “managing” anemia/boosting iron levels, my advice is to look harder at your diet. My cure: eat more liver pate (not on bread – whole grains are bad for iron absorption. I like to spread it on pastrami, roll it up and dip it in horseradish).

  40. For about 1% of the population, Celiac disease is a cause of low iron numbers. Gluten causes an autoimmune response, destroying the part of the small intestine that absorbs iron. I kept pushing on, until I collapsed. In the ER they discovered the cause, which was confirmed by a biopsy of the intestine. This is certainly not everyone’s iron problem, but only a small fraction of the people with Celiac disease are diagnosed. Good luck all. Keep running.

  41. Im a college cross country runner and i was having a lot of problems with my running. I was sluggish and tired and not running like i had been so i went and got my iron levels tested and i had low levels. I started taking iron supplements 2 times days and i feel a little better but im still not up to par. Generally will it take a while for me to get back to where i was, is this normal or should i increase to taking the pills 3 times a day?

  42. My son has been training since the 7th grade to run in a state CC meet by his senior year in High School. He has broke the school records and has been gaining speed and strength each year. However, over this past season we noted that his times started going up AND down. Some meets he was on his game and others you could see the strength drain out. At the end of the race he felt he had enough to finish but just not the strength he is used to. Last night he was numbered 5 out of 100 runners and we watched in horror as he fell far from the state qual. He started out feeling good, but within a few minutes he stated his strength just wasnt there…he nor anyone can explain it. He has strength to finish in the top numbers…just his strength just dosnt sustain him would be the best way at this point to explain it. He is crushed…we are crushed. This story gives us some possible answers and by the looks of it, it has been a good topic for people for a few years. He can still qual for state in track. Any ideas in ramping up for the season? Thank you for the information!

    • KRD, our son, age 16, started XC this fall as the #2 runner on his team. He started having bad races, and at one point, he was finishing behind four runners on his own team. He said that around a mile or so into the race, he would just run out of energy. We had his ferritin level tested. It was 12 — that is rock-bottom of the so-called “normal” range. The doctor put him on supplements (325 Mg ferrous sulfate 2x day.) After three weeks, he ran 50 seconds faster on the same course! He said he felt great. We are keeping him on iron until his ferritin gets over 30, and then he’ll take a daily multivitamin with iron to maintain his level. Low iron isn’t just for females.

      • Very true Tom! Great to hear that you were able to find out about your son’s iron deficiency, and get it taken care of right away! Hopefully now you know about it, you will never have to worry about it again as he can keep track of it. Probably a good idea to get his blood work checked once every few months to check it. You are certainly right, iron deficiency can definitely be found in males too!

  43. I got dignosed with aneamia 2 months ago 4% but not to get another blood test untill 13th feb. would it be safe to start to train again gently? Desprite to go bk!! am a sprinter so would that burn iron of to quickly? Like strides be ok? To start off again?

    • It would be best to wait until you check back with the doctors, if they did tell you to stop training that is. If your iron was that low, you need to give your body time to get back to a healthy level. You could probably do some light cross training activities without the impact. You would not want to just do strides, especially after time off, you will be risking injury. It would be better to just rest up, and you will come back quicker. Hopefully this helps!

  44. I’ve been training for a Marathon for the past 9 weeks – I have 7 weeks to go “April 19th” but recently my intervals session have been a struggle where as 5 weeks ago I felt on top of the world. I would do a threshold “90%” run for around 20 minutes at 3:50 pace “km’s” but now I’m struggling at 4 minutes! I eat healthy, drinking plenty of water to keep me hydrated. Last night doing an interval session 5 x 1000 at 3:18 pace the last 2 intervals I had no power, 2 weeks ago doing the same session @ 3:15 was a breeze! – Could this also be an Iron deficiency? – Thank you for any advice!

  45. My daughter started having iron issues last spring with increased training. She started supplementing with ferrous sulphate 65mg/day and we noticed a turn around in about 3 months. Then her menstrual cycle became very frequent and performance starting declining. In October this was regulated. Now she has been on the same 65 mg/day and in ferritin is up to 67, but the rest of her counts are off: Hemoglobin 13.6, Hematocrit 39.5, Iron is up to 104, TIBC 440, Iron saturation 24. She is a leukemia survivor and due to the chemo we were told this effected her bone density so she is on calcium and we finally sorted out to not take calcium and iron at the same time. No one seems to know why her mentstrual cycle went to one week on one week off. I am her H.S. coach and her mentsrual cycle went crazy at about the same time we went into our most difficult XC training in late August, which is now under control. Her performance is poor now and we don’t know where to turn. Any thoughts and thank you.

    • Hi Brian, thanks for reaching out. Sorry we are not able to provide you any more help in this area, your best bet would be to talk to a physician. Your daughters case is a little too unique for our studies and research. Sorry to hear about that, but it is important that you get her checked out to make sure there is not something else wrong. Best of luck, sorry we could not help more.

  46. I’m an endurance runner. 2 years ago I experienced a sudden drop in my performance: couldn’t even finish a 5k without walking. After reading info on your website, I asked my Dr about my ferritin level, which was at 9 (he wasn’t initially worried about it because I’m over 60). He then put me on 325 mg ferrous sulfate and my running was soon much improved. My ferritin improved to 22.

    Recent training has been going well and ran a good (not great) half marathon 4 weeks ago. But the last 2 weeks I ran horrible 8k and 5k races: I walked numerous times in the 2nd half of both races and finished at paces that were actually worse than my half marathon pace. I was sure it had to be low iron again. So I was surprised when my ferritin level was at 30. Do you think the iron could still be too low even at 30? I started back on 27mg ferrous gluconate after the 1st bad race, do you think I should keep taking the iron supplement?

    • Hi Fred, that is good your ferritin level has improved since taking the tablets, that would definitely have an impact on your training. It is unlikely that your ferritin is still too low at 30, especially if your body has been so low in the past. Have you considered that you could have been overtraining? How has training been prior to this? It could just be that your body needs to back off a little and recover from the half marathon. Your body will take longer to recover as you age, we have explained about overstraining here, see if any of the other symptoms line up for you: Hope this helps! Good luck!

      • Thanks for your reply, coach Tina. I did feel pretty beat up after the half marathon. Surprisingly, I felt fine the next day while doing an easy 3-mile run on the treadmill. I also felt fine on subsequent training runs so I expected I’d do fine on those next races. But maybe the half took more out of me than I realized. It just seems strange that it was such a sudden and almost total collapse about halfway through those last 2 races.

  47. Hi,
    I have a question. Every time I run high mileage e.g. over 10 miles I end up being very nauseous for up to four hours. I have tried to ensure I am well hydrated and eaten enough beforehand and during the run. I try and eat and have an electrolyte drink when I get back but nothing seems to help. Could this be due to iron deficiency? As I know my iron levels have been low in the past…

  48. HI :). I am pretty sure I need an iron supplement and am slightly overwhelmed at what is out there. I am looking to stay on the cheaper, but still good brand end of things. I found one with good reviews at GNC but it says that it is the ferrous fumarate form of iron….is this not the kind I want and any suggestions would be very much appreciated!!!!!

    • Hi Jen! It can be overwhelming, and Runners Connect does not typically make suggestions, but I will email you with the one that I personally take. Anyone else reading this comment who has a similar concern, please email me (tina(at)

  49. This explains a lot. I have been really good at running long and hard including major hills but since May long weekend (Victoria Day) I have noticed I cannot run like before. My original pace for a half marathon is 5:23/km but I’m luck to run at 6:30 and forget about hills. Making an appointment tomorrow.

  50. I just received my daughter’s results and she is in the 40s. She had several friends that were very low (2, 11, 36) She was taking a supplement every other day. Then I had her stop for three weeks so she could be tested. When she stopped, she did notice she was more tired than normal. I have a few questions:

    1 – Could her ferritin level be effected by the iron she was taking 3 weeks ago? Since I read it takes 3 months to move to higher levels, I wonder how it works when you stop taking it.

    2 – What is the level a very good distance runner should shoot for? XC is starting up and I she runs a lot of miles and I want to make sure she is at the correct level. I had heard 60 but before I let her take the suppliments again, I wanted to verify. (Here doctor is older and really I dont think has any experience in this)


    • Hi Bonnie, thanks for reaching out. Your daughters levels are high enough to be safe. I am actually an elite runner myself and mine is 40 consistently. Your iron levels take longer than 3 weeks to show any kind of significant increase or decrease. As long as she is above 30, she is safe, and if she is a high school runner, you do not want to give her unnecessary supplements at this age. It would be best to check in with the athletic training staff at her school, but from the sounds of it, you are fine. You may want to listen to this podcast about female issues with another elite runner, Sarah Crouch. Hope this helps!

  51. Hi,
    about 2 months ago, after reaching my wits end with no answers as to why I am having on going health issues (increased HR, heart palpitation,headaches shortness of breath, vertigo, nausea, vomiting,fatigue, drastic decrease in running performance) my blood work showed that my ferritin levels are 8 and hemoglobin 12.3.
    I am currently taking 45mg of slow release iron pills 2-3x a day along with B12(1000mcg) and vitamin C gummies
    All other blood work is within normal range,and my hormone levels are spot on. complete Cardiac workup with stress test, EKG,echocardiogram came back normal. Liver and kidneys are functioning normally.
    I am currently training for a half marathon which is in 7 weeks. I have been taking iron supplements for 8 weeks now with little signs of improvement. My training is scaled WAY back, consisting of one long SLOW run a week (im up to 10 miles currently), one speed work day(usually about 3-4 miles of intervals-400,800’s or 1600 repeats) and one tempo day (40-60 minutes) and maybe one day of 3-4 easy miles. so about 25-30 miles a week-a far cry from the 80mpw I was used to doing about 20 months ago,and my race times have dramatically decreased from 20min 5ks, to 23min 5ks currently (I did manage to break 23 minutes 2 weeks ago, by 14 seconds, improvement I guess? ) I feel run down on a daily basis an have little energy to complete the few workouts I am doing now. I even stopped lifting weights a year ago thinking I was doing too much (lifting 6 days a week with 6 days a week running). I also am a Professional competitive fitness/figure athlete.but have stopped competing since my symptoms started 20 months ago.
    Scaling down to so much inactivity is driving me crazy.

    In addition,I had a uterine ablation 5 weeks ago to decrease heavy bleeding during periods. My OBGYN thinks that all of my symptoms including the heart palpitations, headaches, fatigue, etc stems from the heavy cycles-which typically was never a problem until 6 months ago. Since i haven’t been competing my body fat has gone up from 7% during my off season to a healthier 13%.
    having said all of this, After my 9 mile run over the weekend I felt an episode come on again-started with heart flutters, a headache, and my HR took all day to get just in the 80’s. (my resting HR is typically 46-50) it stayed over 100 for about 4 hours afterwards. I felt nauseated, lght headed and was pretty much wiped out the rest of the day. I know i properly hydrated and refueled after the run, so is this really just low ferritin levels causing me such grief? should i still continue half marathon training and hope i have a decent time (am shooting for 1:38) or should i just do enough to keep a base and worry about training and racing when my levels come back up?
    i get my levels tested again in 2 weeks and am hoping the levels are rising at least a little, ven though i really don’t feel much better. i still experience the symptoms mentioned earlier after most races or hard workouts. some days are worse than others.

    Do you have any advice I could use to help get myself back in shape without feeling like death warmed over? Ive been anemic in the past (during pregnancies and when i was younger and in college) but have never felt this run down before. Is this something I can train through? I am really longing to get back in the gym and see the 20’s again for 5ks as well as compete in figure/fitness again.

  52. Hi coach,
    I am mother of 2 year, started running again after she was born in June 14. did full marathon in 4:50 in Jan 15 and was targeting for under 4:30 in 22nd Nov run. I got my haemoglobin report 2 days back with 8.9 value. I had been feeling very tired , exhausted compared to my previous run. should I go for 22nd Nov run . 1 plan I can think of is attempting run with comparative slow pace..Please suggest.

  53. Hi guys after reading these posts and being a runner myself.. I suffer anaemia .. Low ferritin level of 19.. However I also am low in active b 12.. This has caused me to stop running now for the last month.. Lightheaded and fatigue. So when being tested for low iron make sure you are tested for b 12 as this very important factor is needed for iron absorption and red blood cell reproduction!!

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  56. Thank you for writing this article. I just found out that I’m anemic and now I understand why. I will be adding a supplement to my diet for now on!

  57. my daughter is 16 5’5″ 111 lbs and her ferritin level was just tested its 12.2. She is a cross country runner and I feel she needs a supplement. Her doctor said because she is not anemic he does not do anything. I want to be sure to give her the right dosing. Any suggestions.

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