Gordy & Hellosailor,
Thanks for your comments.
The study not withstanding, my very noticable fatigue occurred when diving Florida
waters off of Panama
City, Islamorda, Key Largo
, etc. My log book indicates the water
temp in all cases was above 75 degrees, but no higher than 85 degrees.
As for physical conditioning, which is very much a part of oxygen uptake, I was engaged at that time in: bicycle riding 3 times a week between 20 & 60 miles at a clip, roller blading twice a week between 15 and 40 miles each session, hitting the gym 3 times a week for cardio & weight training, and taking weekly karate classes
. Body fat was down to 12% and VO2 testing (max oxygen uptake) was extremely good ( after all that exercise it had better be).
In short, on land I had very good conditioning and could stick with energy expenditure way beyond the average Joe.
Hellosailor is right on in terms of heat flow in water
, even in waters most people think of as warm (like Florida). For those of you who dive off of dive boats, you know that not only do you come out of the water cool or cold, but you cool down even more on the suface interval when the dive boat powers up and heads for the next dive destination
. By the end of the day you are normally chilled to the bone and physically exhasuted (assuming you dove the tables), at least that has been my experience.
I think the message is: everyone is different and the only thing that really counts is what the individual experience is. My experience is that I'm less tired on nitrox all other factors being equal. For me it's right. Your milage may vary.