Yoga & the Tanya Streeter Perspective
Cliff wrote the following concerning Tanya's training:
"I asked her about her training routine - she does NO Yoga at all... Basically she utilizes sound scientific training for both aerobic and anaerobic methods."
While yoga maybe considered non-scientific to some, the mechanisms of benefit are becoming more and more understood. The most commonly practiced type of pranayama yoga is the alternate nostril inhale(1unit):hold(4units):exhale(2units). A beginner practicing this may quickly develop better lung & diaphragm function, but intermediate to advanced divers will not benefit much from this exercise unless either they do it for a very long period each day, or do extremely long cycles (i.e. 16:64:32 or more).
This type of breathing induces 'cyclic hypoxia', also known as 'interval hypoxic training.' The hemoglobin O2 saturation rises and falls with each breath cycle, but it will only cycle up and down if the cycle time is long enough. During each inhale, the body goes through a reoxygenation phase, during which free radicals are formed. The body develops defense mechanisms against this, the two most important of which are an increase in the EPO hormone and a drastic increase in natural antioxidant production. The increase in EPO levels causes red blood cells to be produced, with a corresponding increase in hemoglobin and hematocrit (assuming essential nutrients including iron are present). The increase in hemoglobin and hematocrit increase the total oxygen storage capacity of the blood. A freediver with 'good blood' stores about 30-50% of his oxygen in his blood (the difference between good blood and bad blood is the equivalent of about 5 litres of air). The increase in natural antioxidants helps the body in the late stages of hypoxia, and if you look at the ATP cycle you'll find that elevated antioxidant levels can help retention of consciousness in the late stages of hypoxia. So, pranayama breathing, or other similar exercises, both increase the O2 storage capacity of the blood, and help you remain conscious in low oxygen.
The yogis will tell you that the reason for alternating nostrils is due to flows of prana--whether this has a scientific basis is still in question...
Eric Fattah
BC, Canada