Well I have to say thanks to Simon, for his efforts to communicate and work with us in a complimentary way!
Will be in touch about your ideas for experiments.
I find that a dive for many of us, if not most, is not necessarily most significantly limited by the use of O2 from the lungs. So, where it may be estimated that 42% of our O2 is from the storage of air in our lungs, this does not consider the effect that filling the lungs have on the dive and what proportions of that O2 store are required under various diving techniques. Fundamental to the meaningfullness of specific O2 stores, is when and how do they get accessed, under the various conditions. While diving on exhale most of us have found we can dive for similar lengths of time when compared to our inhale dives.
So, the idea that losing some 28% of our O2 stores, that is mainly accessible to our body core and brain during a dive, may not imply what the number suggests. Most of us here are aware of the difficulties in dealing with bouyancy and changes in bouyancy with depth. These difficulties are generally experienced to have a dramatic overall effect on the dive. Exertion at the surface is maximal and energy consumption is most inefficient, due to the presence of air and inhalations, which hinder the diving reflexes from occuring. The inefficiency comes from leg exertion tapping your O2 stores of the lungs, increases in heart rate as the body prepares for inhale exercise, and increase in metabolism temporarily(?). In general then, it is most likely that we will see a sharp drop in our 42% of O2 stores until we slow down our kicks and settle in to the sinking phase. The significance of the waste of energy is profound, and would be nice to measure in a controlled environment.
To contrast this, in exhale diving, one can weight themself to sinking almost immediately, thereby alleviating this exertion and rise in body activity. Not to mention the induction of diving reflexes as the body senses the prominent apnea conditions that come immediately without the inhale.
As a test try the following: See how long you can hold your breath while laying down on a passive exhale. Then at a similar state of initial relaxation, inhale and hold your breath. Immediately begin a brisk walk while continuing to hold your breath. Stop walking after 20 seconds and continue to hold your breath for max.
This test I would say is close to a comparison of a dive profile under inhale and exhale, without the comparison of diving reflexes.
Regarding myoglobin, due to blood shunting, one can have leg failure at depth if there are inadequate O2 stores in the tissues themselves. So I wonder if it is more important to understand an increase in myoglobin as a relative increase to previous myoglobin levels as opposed to comparing it to your overall body O2 storage. If you increase your myoglobin to double your previous amounts, what increase will this imply to the duration of power supplied by the legs. It is possible that diving on exhale increases myoglobin levels in current tissues, as well under appropriate stress, promotes the development of further muscle tissue with these higher myoglobin levels. So, potential increases to myoglobin stores, should include the tendency to promote the muscle tissue growth as well, correct?
Look forward to discovering whether this occurs and to what effect on top of just the numbers.
Another thing with exhale diving, is that it seems to strongly influence and train your body for diving reflexes. It would be interesting to gather those people who do not get blood shunts very easily while diving, and doing controlled exhale dives, look for increases in effect of diving reflexes and the timeliness of them. In my experience, I could rarely achieve a blood shunt when diving to depths up to 50m. Within a week of practicing exhale dives, I was experiencing blood shunts on all dives greater than 15-20m. I went from feeling exertion on a 50m dive, to feeling the same on a 71m within the next 5 dive sessions, whereas I had previously been diving constantly all year between 30-45m.
Most of this has been said before through this site, but a summary appeared relevant to this thread. Hope it is accurate in representing the ideas throughout our freediving community and that it helps the new people to understand the perspective freedivers are using in some of these concepts.
Cheers,
Tyler
Will be in touch about your ideas for experiments.
I find that a dive for many of us, if not most, is not necessarily most significantly limited by the use of O2 from the lungs. So, where it may be estimated that 42% of our O2 is from the storage of air in our lungs, this does not consider the effect that filling the lungs have on the dive and what proportions of that O2 store are required under various diving techniques. Fundamental to the meaningfullness of specific O2 stores, is when and how do they get accessed, under the various conditions. While diving on exhale most of us have found we can dive for similar lengths of time when compared to our inhale dives.
So, the idea that losing some 28% of our O2 stores, that is mainly accessible to our body core and brain during a dive, may not imply what the number suggests. Most of us here are aware of the difficulties in dealing with bouyancy and changes in bouyancy with depth. These difficulties are generally experienced to have a dramatic overall effect on the dive. Exertion at the surface is maximal and energy consumption is most inefficient, due to the presence of air and inhalations, which hinder the diving reflexes from occuring. The inefficiency comes from leg exertion tapping your O2 stores of the lungs, increases in heart rate as the body prepares for inhale exercise, and increase in metabolism temporarily(?). In general then, it is most likely that we will see a sharp drop in our 42% of O2 stores until we slow down our kicks and settle in to the sinking phase. The significance of the waste of energy is profound, and would be nice to measure in a controlled environment.
To contrast this, in exhale diving, one can weight themself to sinking almost immediately, thereby alleviating this exertion and rise in body activity. Not to mention the induction of diving reflexes as the body senses the prominent apnea conditions that come immediately without the inhale.
As a test try the following: See how long you can hold your breath while laying down on a passive exhale. Then at a similar state of initial relaxation, inhale and hold your breath. Immediately begin a brisk walk while continuing to hold your breath. Stop walking after 20 seconds and continue to hold your breath for max.
This test I would say is close to a comparison of a dive profile under inhale and exhale, without the comparison of diving reflexes.
Regarding myoglobin, due to blood shunting, one can have leg failure at depth if there are inadequate O2 stores in the tissues themselves. So I wonder if it is more important to understand an increase in myoglobin as a relative increase to previous myoglobin levels as opposed to comparing it to your overall body O2 storage. If you increase your myoglobin to double your previous amounts, what increase will this imply to the duration of power supplied by the legs. It is possible that diving on exhale increases myoglobin levels in current tissues, as well under appropriate stress, promotes the development of further muscle tissue with these higher myoglobin levels. So, potential increases to myoglobin stores, should include the tendency to promote the muscle tissue growth as well, correct?
Look forward to discovering whether this occurs and to what effect on top of just the numbers.
Another thing with exhale diving, is that it seems to strongly influence and train your body for diving reflexes. It would be interesting to gather those people who do not get blood shunts very easily while diving, and doing controlled exhale dives, look for increases in effect of diving reflexes and the timeliness of them. In my experience, I could rarely achieve a blood shunt when diving to depths up to 50m. Within a week of practicing exhale dives, I was experiencing blood shunts on all dives greater than 15-20m. I went from feeling exertion on a 50m dive, to feeling the same on a 71m within the next 5 dive sessions, whereas I had previously been diving constantly all year between 30-45m.
Most of this has been said before through this site, but a summary appeared relevant to this thread. Hope it is accurate in representing the ideas throughout our freediving community and that it helps the new people to understand the perspective freedivers are using in some of these concepts.
Cheers,
Tyler
Last edited:
