Physiological experiment at Lanchester University

Some time back I got an email from a scientist at Lanchester University. He was looking for freediving volunteers for his current physiology project, involving cardiovascular regulation and control by breathing. After learning a little about the experiments and the hypothesis, I booked my flight for Friday 26th February. I was gonna be a test bunny :)


The whole set-up was very professionel, and the tests were all non-invasive. The only thing I had to do was lying still and at times hold my breath. After being all wired up of course! The responsible for the experiment had even learned "blow-tap-talk" in order to wake up any blackout victims (although it's very hard to push that far on dry land...).


It was a fun experience, and it's always interesting to learn more about what happens in the body during breath hold. We had some interesting discussions, and I'm very glad I took the trip.

A closer look at hypoxia

Lately, my days have been occupied by less freediving and more studying. I'm still training and trying to stay in shape, but having a break from the competition rush at the moment.

I'm currently working on my bachelor project (to be finished in June 2010), which is somehow related to freediving. I will be studying how hypoxia is increasing the formation of new blood vessels in the body. A protein called hypoxia-inducible factor is responsible for activating several genes, which give us a physical response and help the body to cope with the stress.

From a freediving perspective, it's facinating to learn more about what's happening in the body when it's faced with low oxygen. There's still lots to learn.

Designated scientists

Erika and team even brought their lab out on sea two of the competition days to measure the oxygen saturation of the deep freedivers shortly after surfacing. One sign of a lung squeeze (an injury that can come from the lungs not coping with the big pressure at depth) is a reduced oxygen level in the blood up to several hours after the dive.

I showed a 99% saturation just two minutes after coming up from 57m in CWT, which is very very good. This means that my body had got the time to adjust properly, and that I was well within the depth limits that my lungs can handle. Very good indeed!


I also tried Sebastians spirometer, measuring my lung volume. On a normal inhale, I had 4,59 liters of air. This is an increase from a test last autumn which showed 4,3 liters. Most likely it is the repeated deep diving, the morning yoga and lung stretching that has worked for me.


So, even though I don't have those huge "Stig-" or "Dave Mullins-lungs", they are adapting to my freediving :)

With packing (gulping extra air) I reached 4,94 liters. This isn't as much as many other people get from doing packing, but I'm not eager to stress my lungs too much and overdo this. Packing is only safe if you train it regularly and correctly.

And again, it's not all about how much air you bring down there, it's also a lot about how good you are at saving oxygen...

The secret of the long statics: the Spleen!

Erika Schagatay, a swedish scientist from the Mid Sweeden University, was in Dahab for the Bizzi Blue Hole competition doing a research project on the spleen. She has done several projects about the human diving respons previously, and now her focus is on the effect freediving has on the spleen.

She has previously been to Nordic Deep , doing a set of spleen on the freedivers there, and has confirmed the fact that the spleen contracts during repeated breath holds. This releases extra red blood cells which the freediver can utilise to store more oxygen and prelong the breath hold. Erika estimates the effect to give up to 30 sek extra in a static attempt! I think I wanna take good care of my spleen now....


I gladly participated in the test, which inclueded two dry breath holds with different warm ups where my spleen was measured continously by ultra sound. The heart rate and oxygen saturation was also measured throughout the test. The main question Erika was asking this time was when do the spleen contract? Their results will be very interesting and might give us freedivers a better idea of how to warm up for a max dive most efficiently.


As you can see on the next picture, my spleen definatly contracted during a static apnea, which means it is a good idea for me to do one or two warm up dives before a max. Then I will have more red blood cells in circulation, and will be able to dive deeper. I must say the human body is a brilliant organism, and the more I learn, the more impressed and curious I become.