New freediver, currently at the Great Barrier Reef AUS - iron defficiency and freediving

adrian.u said:

I suspect that anaemia could lead to a higher possibility of blackout if you tend to push a bit towards hypoxia when freediving.

I'm pretty sure it's true that the body will be able to cope better with it to some degree as you do more breathhold/freedive training (improved dive response meaning better oxygen use overall, incl. spleen adaptations so there's a bit more 'fresh' O2 added into blood when needed, etc.)

Still, I think it'd be wise to be wary of the possibility you could become somewhat hypoxic before the hypercapnia causes you to reach the point where you have enough discomfort (i.e. urge to breathe) to discontinue the dive/breathhold (perhaps a bit like hyperventilating beforehand), especially if your CO2 tolerance has been improving with training...

Next time you're doing some near-max dry static breathholds, it might be worth using a pulse oximeter, so you can see if you are actually managing to bring your spO2 down significantly. (I'm assuming that anaemia would affect spO2 sufficiently for it to detect that - I'm not 100% sure, although this article suggests it probably should...?)

Ideally, of course, you'd want to try to reduce the anaemia if you can.

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