Most runners who think they have low iron have never had the right test. And most who supplement for it never needed to.
Dr Alannah McKay is a Senior Lecturer at the Mary MacKillop Institute for Health Research, Australian Catholic University, where she studies iron metabolism in athletes. She trained full-time as a ballet dancer from twelve to eighteen and thinks she was iron deficient through most of it — never tested, never treated. Her PhD, done in partnership with the Australian Institute of Sport, was awarded the Dean's List honour, and she now works alongside Professor Louise Burke on female athlete physiology.
In this episode:
- What ferritin actually measures, and why a haemoglobin test alone tells you almost nothing
- The three stages of iron deficiency — and where you can still intervene
- Why the duration of your run matters more than the intensity
- Hepcidin: the hormone that blocks iron absorption for hours after training
- The thirty-minute window after a run when absorption is best
- Why "100mg" on a supplement bottle is often 20mg of what counts
- Ferrous sulphate vs bisglycinate — and what the evidence actually supports
- What happens to your iron across a hard training block or at altitude
- Home ferritin tests, and why she's not ready to recommend them yet
- How often a recreational runner should realistically get screened
⚠️ Educational only — not medical advice. Supplementing iron without testing carries real risk, including for people with undiagnosed haemochromatosis. Talk to your doctor before changing anything.
Chapters
01:00 From ballet to iron research
02:00 What iron does in the body
05:00 Ferritin, haemoglobin and the three stages
08:00 How iron is absorbed — and what blocks it
11:30 Who's most at risk
16:30 Hepcidin: why training blocks absorption
20:00 The window after your run
23:30 Low carb, keto and iron
25:00 Haem vs non-haem, and vitamin C
32:00 Can you have too much iron?
34:30 Supplement forms
37:00 Symptoms, and why fatigue is a poor signal
39:30 How often to get screened
40:30 Home ferritin tests
43:00 Hard training blocks and altitude
47:00 Dosing: elemental iron, timing and alternate days
54:00 What she'd study next
Find Dr Alannah McKay
LinkedIn: linkedin.com/in/alannah-mckay
ACU profile and email: acu.edu.au
Google Scholar: scholar.google.com
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I'm Joost, running coach at Pace Buddies. I coach recreational runners using an aerobic-first approach — building the engine properly before layering speed on top, instead of the other way round.
If this episode left you wondering whether something in your own training is holding you back, book a free thirty-minute call. No pitch deck, no pressure. We look at what you're actually doing now, where the gaps are, and whether coaching would help — and if it wouldn't, I'll tell you that.
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