lung capacity?air consumption?

[coach_izzy]

Good point Cameron. However, considering the origen of the increase in cardiac and respiratory activity, I do think that training and experience have a FAR more significant role in gas consumption than physical fitness as the OP addressed it.

A diver going against current and diver experiencing entanglement will both probably experience elevated cardiovascular activity. The entangled diver however, starts with a psychological reaction, that turns into a hormonal response, that translates into a physical response. How well a diver is prepared to cope with the situation will have a much higher likelihood of experiencing less stress, keep his physical response under control, and then most likely, move on. Put a new diver under the same conditions and we'll see a far more pronounced physical response, regardless of the levels of fitness.

The effects of epinephrin cause an increase in CV response, yes that's true, but also bring certain supresive responses that are not found with responses to physical demands only.

The point that you also brought up and liked very much was how physical the stress hormones can be, and how a conditioned body will cope with them a whole lot better than somebody with low levels of fitness. An unfit diver under a new type of stress and the effects of the powerful epinephrin, has a very high chance of experiencing cardiac failure, regardless of how experienced he can be, versus a physically fit diver, who can better tolerate the "fight or flight" response and its physical responses.

Thanks again Cameron. It's good to see you in the board again. I do not know if it's you who has been absent or it has been me. Either way, your contributions are always intelligent and very much appreciated. Take care and happy diving.

 

[dumpsterDiver]

There is no hard research on this, but it is not a huge leap of logic to think that decreased HR response due to fitness could slow the development of a panic response. There are many better reasons to get fit for diving, and experience is much more likely to keep you from panicking than fitness itself, but it might indeed have its own influence on the cycle.

Cameron

I suspect that the athlete's ability to punish and train his body and maintain a certain level of concentration while enduring a challenging cardio-vascular workout (on a bike, running, swimming etc) may translate to the ability to retain focus underwater when the level of physical exertion and stress requires it.

 

[Charlie99]

My anectdotal observation is that my overall level of fitness or cardiovascular fitness has no effect at all upon my SAC on a normal, very slow, loafing along sort of dive. OTOH, if I'm in good shape, my SAC doesn't go up as fast when I'm doing a transit swim at 1kt, or going 1.5kts to make headway against a current.

Upon noticing this and reflecting a bit, I realized that this shouldn't have been a surprise considering what happens when I start exercising on an inclined treadmill. A while after resuming an exercise regime I can do a combination of % incline and speed while talking and breathing normally that a few weeks earlier would have had me huffing, puffing, and panting.

I don't know the medical theory behind it, but the basic fact is that when I'm in good shape I can do more work without "getting out of breath".

 

[RoyN]

Have no problem with my lung. Because I have been diving frequently every week on Saturday, I have to worry about the dive table then how much air I have left. Most of my average air I usually have left is about 700 to 1000. Sometimes I waste if foolishly down to 120 but thats because I'm on the surface just breathing on the regulator waiting for divers to go up the boat before I do.