[homodelphinus]

Very interesting what gabriel proposes about decreasing your blood PH, does have consecuences though , the more serious being the risk of suffering a B.O witha lower thresold (it´s the hypoxia, not the hypercapnia what causes it, it doesn´t matter if you have a very high blood CO2 content, like Eric Fattah states, you can learn to tolerate it, in fact high PCO2 triggers the drive to breath through brain chemoreceptors, if you hyperventilate or alkalinize blood by other means you alterate thid mechanism).

I do have some suggestions for those of you who are newbies or more advanced freedivers and want to improve your apnea time. The concept is simple, the more efficient your body utilizes its energy sources, the more time you get out of a single breath. these are my recommendations:

1. improve your aerobic metabolism: this means getting in shape. training in the aerobic zone ( swimming, jogging, bycicle, whatever you prefer). mantaining a heart rate between 70 and 85% of your maximun HR for age troughout the workout (220 - age=maximun Hr). for this i recommend using a heart rate monitor to keep track of your hear rate. this trainning improves your bottom time wen doing dynamic apnea. on the long run improves your static as well by decreasing basal heart rate and diminishing oxygen consumption.

2. increase your pulmonary capacity: there are several ways of doing this

a. elasticity: increasing your chest elasticity by doing stretching of rib cage and back
b. step breathing: like they do on yoga and pranayama: diaphragmatic (belly breathing) - thoracic breathing (chest wall) - clavicular. we can discuss this topic in detail if anyone wishes to.
c. PRANAYAMA: orientad style breathing. improves chest compliance and teaches how to proper breathe. very interesting
d. The powerlung and other devices improve chest wall capacity by creating resistance breathing.
e. resistance breathing while swimming or jogging: can be done simply by doing your exercise while breathing through a long, narrow snorkel.

3. anaerobic trainning: improves your tolerance to CO2 build up: doing repetition dives with short intervals of breathing between reps. should be guided and always spotted by someone.

Hope to hear some comments by gabriel, eric or anyone else interested in the subject.


alejandro Jiménez, M.D.