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A Question on Diet...

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Deeper Blue Hypoxyphiliac
Oct 24, 2002
Hey all,

Just a quick one - I'm looking to see if anyone has noticed any differences in their breath-hold from living on a low sugar/low starch (ie low carb) diet. I know Wal told me once before he tried it, and statics got much harder, but I've been living on about 50g of carbs a day for the last 7 odd weeks, and after getting back into it from a year off, it seems to be easier to push myself.

Anyone else noticed anything like this? Would this just be a by-product of muscle loss? (I'm talking improvements in both static and dynamic)


On a low carb diet, you produce less CO2 per unit O2 consumed, meaning that your contractions may come much later, nearly as if you hyperventilated, making it easier to push it to the max. However, your ultimate time will probably suffer, because of the decreased efficiency of fat-burning vs. carb burning.
Aloha Loopy

Good to hear from you. Hope that life 'out west' is treating you well.

A few years ago, I overheard a conversation between two guys that have been diving longer than I. They were talking about friends that were lost while diving and dieting. It sounds like Eric has worked out the chemistry involved. Maybe a good time to be extra careful.

Cheers Eric - that pretty much coincides with what I've experienced

Bill - will do mate, I'm minus a buddy at the moment, so all my trainings dry. Been out of the water for a number of months now (like 10 :() but getting keen to get back in, so starting the training. Well done again on the record :)
hmmm i just know that i cut out carbs almost totally and lost 8lbs in two months....
Low carb diet is dangerous when freediving. We recently studied the effect of low carb (glycogen depletion) on apnea. The results were published at the last UHMS meeting and a publication is accepted and will appear in the European Journal of Applied Physiology soon.
The summary was that if you depleat your carbs from diet and exercise, your body will consume oxygen faster during apnea and also the carbon dioxide will accumulate slower. This means that the urge to breath will be delayed, so you dont get the warnings in time to surface. (Which can be interpreted as "easier" to hold your breath since the signals are reduced)

I personally think that this can explain why some accidents among experienced divers or spearfishers. If you go diving for a full day without replenishing carbs during the day you might shift your metabolism and risk a blackout without the normal warning signals. This also explains many cases of LMC and LOC during competitions in apnea where the athletes skipped the breakfast.

Pure Fat metabolism consumes approx 7% more oxygen and produces 30% less CO2 than pure carbohydrate metabolism

Dr Peter Lindholm
Last edited:
Hi Dr Lindholm,

It would be great if you could post a link to research when it is published. I was doing the Atkins diet before I got into freediving and was considering it again now. However any research like this could help me with a more informed decision.

I find that eating lots of carbs (pasta, cereal etc.) several hours before apnea improves my performance.

I could eat breakfast cereals all day..... :p

Hi Dr Lindholm,

First of all welcome to the forum:)

What about high protein moderate carb diet? Like 140-160gr protein daily and smilar amount or little more carb. I am around 80-82kg and regular gym routine:hmm like 4-5 days a week..
G'Day Dr Lindholm, and again welcome to the forum!

You mention that skipping breakfast might lead to a carbohydrate depletion by the afternoon, which could reduce breathold times - my question is what kind of time frame are you looking at before these effects kick in? Say I have a heavy gym session, burn up all my glucose stores and then go for a dive, will I be at risk? Dr Atkins mentions that it takes about two days for the body to convert from "glycolisis" to "lipolisis" - does this factor into the equations at all?

Thanks very much for your input - I'd also be interested in seeing a copy of the study when it becomes available :)

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