I may have been iron deficient as hell

This is not mind blowing stuff to most but I’m sure there’s ignorant people like me who don’t think about this stuff much and suffering from it.

If you watch Chris Miller podcast, that was the first topic they talked about in today’s video. And it’s covered a million times I’m sure by TR folk, Dylan Johnson etc too…

My coach asked me to take a blood test when we first started working together 2 months ago. I idiotically picked tests that included everything he wanted to see except iron levels (there were some iron related stuff but not exact thing he was asking for)

I really don’t know the science behind it at all but he asked me to take iron supplements to be safe cause just looking at other indicators in the test he’d be shocked if I’m at a healthy level. And given that I sweat A TON, I maybe losing a lot. Never taken supplements in my life either and I’ve been riding pretty seriously for the last 9 years.

So anyway I started taking them. It’s been 2 months. I never really paid attention and put the 2+2 together but watching that video kinda made me realize…

For the last 2 months I’ve been taking them, I’ve felt pretty amazing in comparison. I kind of assumed 11 hours a week on the bike is finally paying off in fitness but really, I feel like beginning of this year I couldn’t do 11 hours at all. I was never able to ride this much in previous years either. I’d do 8-10 hour weeks during base period mostly Z2. I felt tired, didn’t wanna move an inch besides cycling, felt mid day slumps every day and back to back 2.5 hours days on the bike seemed like a nightmare and I needed days off every other day. I couldn’t keep the 8 hour weeks either. Would need a few 4-5 hour weeks to get my energy and motivation back.

Now I move all day, work on my bike, organize garage, work, run errands, get on a 2.5 hour ride go to bed and I’m ready to do it all over again. Some days there’s a lot of work and errands to do and I ride very late on the trainer at 9pm-11pm with sweet spot training. Get a little bit to eat, go to bed and next day I’m still recovered enough for a 4.5 hours endurance ride. It’s not other factors either. If anything I don’t eat as clean nowadays and my sleep didn’t change. It’s pretty bad compared to last years cause of work if anything.

Anyway, I’m pretty stoked and if you haven’t considered before, get a blood test!
I really want this feeling to never end.

(I’m 40 btw so not exactly a youngster with unlimited energy)


This is worth re-iterating when it comes to iron. Too much is BAD too. Get a blood test before supplementing! You don’t want to be taking in more / too much if your levels are in the correct ranges.

With that said, there are studies that show that endurance athletes are much more likely to be Iron, Magnesium, Potassium Deficient (I think it was all three) than the general population. And when you look at Iron, it’s critical for red blood cell production, and even more so if you’re going to altitude.


i concur on the blood test idea. i get (and pay for) tests 2 x per year. the company i use in the UK are called forth edge. they do different levels and can add in other markers at your request. its reassuring to know you aren’t lacking or in excess of the various metrics, as you tryig to move the needle up.


Not directed at the OP, but It’s also important to understand why you’re iron deficient. There can be underlying reasons for the deficiency that are not related to sport and consulting with a doctor is highly recommended. My iron deficiency led to a celiac disease diagnosis.


As we said in the haz-mat business “dose makes the poison” (I’m no in the business anymore but I did pick up a thing or two when I was.)

Another thing to keep in mind is that supplements are not a regulated industry, so quality can be a crap shoot. If you can get a doctor to prescribe a phama grade supplement with dosage all the better.

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Iron deficiency is something that should be discussed with a medical doctor, not a cycling coach or podcast. There is no way I would ever recommend an iron supplement based on an OTC blood test. The proper way to do this is, “You might be iron deficient. You should ask your doctor about getting tested and see what they think.”

I was anemic in my teens and iron supplementation helped. Knowing what that feels like now, most adult endurance athletes probably do not need iron supplementation unless they are couch-ridden and sleeping 12 hours per day outside their workouts.

So what OP describes lines up with that, but man, there is no way I would just guess about iron supplementation given the potential consequences if you’re wrong. Even if he’s right, man making medical diagnoses is not a risk I’m taking as a coach.

Last, iron deficiency is pretty readily addressed through dietary changes. Be careful messing with iron supplements.


Hot tip, greatest iron “supplement” on the market. I’m probably getting 200% of the recommend daily intake per “Brendan Serving” :rofl:


Yeah my goto breakfast. :joy: Add blueberries and too with granola on ride days.


Needs repeating, multiple times.

In 2019 my levels were low (seriously ill, anemia, lots of tests), but without evidence of a bleed, Iron supplements were not prescribed or recommend. I asked about this and wanted some detail, Iron in particular, supplements when not needed are seriously bad.

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In my honest opinion the original post is extremely irresponsible.

Even with low levels clinically diagnosed supplementation is not recommended in many cases.


These are your doc’s words? I think there is probably a gray area between the average person with a desk job who doesn’t train with low iron levels and an athlete trying to workout 10 hours per week with low levels.

Why the levels are low should be identified but after that I’m not seeing a problem with adjusting them up temporarily rather than continuing to train 10 hours per week and the levels never coming up.

(I’m not advising anyone to do anything without consulting a doc, and the OP should get a test to know his levels for sure rather than rely on a coach’s ideas.)

I have a very good relationship with my GP, they are fully aware of my sporting background, history, and therefore the specialists I later had contact with. Even so, for me, iron tablets NOT recomended, this may have been incorrect but I trust the medical professionals, over someone saying they supplimented and felt good.

If anyone is conserned get a proper medical test and recommends from a professional.

Definitely. Everyone said I was overtraining but my iron deficiency was caused by a bowel (colon) cancer blocking iron absorption. Now I am back to normal (iron wise at least :wink: ) I’ll leave it to the docs to advise as apparently any overdose in iron can have the same effect as a deficiency and I wouldn’t want to go through that again. Chemotherapy was a relative ‘walk in the park’ compared to the iron deficiency!

Thanks for all the messages.
People thinking my post is irresponsible

  • I said: “Take a blood test” I didn’t say: “Take supplements today”
  • The whole post is about MY experience. Not a medical advice thread. Goal is to get people to think about this since it’s so common in endurance athletes.
  • I know training coach is not a doctor but unfortunately I am a freelancer with no free healthcare. My healthcare / insurance is through my partner who loves in the UK. My visits there aren’t long enough to take a test these days. I can’t get a free doctor’s consultation or blood test done in the US. Just the test was expensive enough. All in all, I’m very happy that the difference has been day and night. I’m surprised I was able to train as much as I did before supplementing.
  • I’ll be taking another blood test in couple months to see if supplementing has helped (and not just rely on feel)
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I really don’t know the science behind it at all but he asked me to take iron supplements to be safe cause just looking at other indicators in the test he’d be shocked if I’m at a healthy level. And given that I sweat A TON, I maybe losing a lot

Just for clarification, you’re absolutely not losing iron in your sweat. You may be shifting a relatively high amount of water and sodium - but so long as you’re hydrating well (with isotonic stuff ideally, not plain old water) during/post workouts your kidneys have you covered. A couple of billion years of evolution have this sorted.

[Unless you’re literally sweating blood in which case, you have bigger problems than cycling to worry about].

Worth pointing out that if you really are iron deficient (your Full Blood Count would show smaller than usual red cells and possibly a degree of anaemia - as defined by a low haemoglobin) the cause needs investigating. Adding more dietary iron may help, but there are causes that range from the easy to fix to the pretty serious. I appreciate that your access to healthcare is limited.

Hope this is useful!

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This bit is right but… I don’t want to nit-pick, but you can’t really conclude your new fitness is down to iron levels. You say you didn’t actually do a blood test for iron deficiency, so you don’t really know if you were. And now you haven’t done another test to see if you are now out of deficiency. It might all add up, but you haven’t actually tested it.

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That’s why the topic title says “may have been”

But you have no reference, previous test, to draw any conclusions against.

You can not possibility know, given the information you have shared.

The only thing you can conclude is you are luckily you haven’t given yourself iron posioning (Iron toxicity.)

Worth reading (Caveat: Not an expert, make your own conclusions, YMMV)

Some tidbits: Athletes more at risk, methods of loss (sweat is listed per the study and references), iron toxic in excess. “Chronic iron supplementation in the presence of normal and high ferritin values is not recommended.” “Iron supplementation is necessary for altitude training.”

I’m personally interested in that last one.

“Altitude training increases the iron requirements by 100–200 mg of elemental iron/day.”

Everything above still holds. Consult with a physician and get tests before supplementing.

yeah just to add here, while iron deficiency is common in females… in healthy men around 20-60 years that is a much less common thing and should be considered a red flag. it may just be down to diet in some cases, but overall it should be medically documented and raise some questions that are best addressed by your (primary care) physician.