Oxygen "debt"

Thank you, Barry and Jim, for the info on CO2.........I never thought of that. But it does help explain why you feel discomfort way before you really have a physical need. However comma, I still have an unanswered question, to wit: at what point, be it time or distance, do we meet that old devil "oxygen debt"? On a straight swim, is it after 30 seconds ? After 25 yards ? Let me explain the motivation for the question : As some of you may know, I am and have always been a flyer. My other strokes pretty much stink. Still, I am sometimes seduced by the dark side and I enter an IM event. What precipitated this question of O2 debt was a comment by a well-meaning young Coach after my most recent 100 IM. "Bert, you need to breathe more than once or twice on that first length of the IM because you are putting yourself in 'oxygen debt'." He went on : " when you pushed off on the backstroke leg, your face was beet red " Now, since I thought I new better, I began to question this advice. Here is why : After 20 years of pounding out 50 fly races, I have learned through trial and error that each breath costs me .30 seconds. Since I would rather win than breathe, I suffer through the discomfort. But I also know that this trick doesn't work on a 100 because (I guess) of Oxygen debt. Too much is too much, and this is exactly why they made ***-stroke a surface stroke. Anyway, we're focusing here on an IM... 1. I feel no discomfort after a 25 fly without a breath, especially knowing that the "breathers stroke" is coming next. 2. If my face was red, it was probably out of shame that someone might actually see me doing backstroke. 3. I had my best time in 4 years !!! So, please, tell me exactly at what point in a race, time or distance-wise, can I expect to encounter this O2 debt monster ?

Thank you, Barry and Jim, for the info on CO2.........I never thought of that. But it does help explain why you feel discomfort way before you really have a physical need. However comma, I still have an unanswered question, to wit: at what point, be it time or distance, do we meet that old devil "oxygen debt"? On a straight swim, is it after 30 seconds ? After 25 yards ? Let me explain the motivation for the question : As some of you may know, I am and have always been a flyer. My other strokes pretty much stink. Still, I am sometimes seduced by the dark side and I enter an IM event. What precipitated this question of O2 debt was a comment by a well-meaning young Coach after my most recent 100 IM. "Bert, you need to breathe more than once or twice on that first length of the IM because you are putting yourself in 'oxygen debt'." He went on : " when you pushed off on the backstroke leg, your face was beet red " Now, since I thought I new better, I began to question this advice. Here is why : After 20 years of pounding out 50 fly races, I have learned through trial and error that each breath costs me .30 seconds. Since I would rather win than breathe, I suffer through the discomfort. But I also know that this trick doesn't work on a 100 because (I guess) of Oxygen debt. Too much is too much, and this is exactly why they made ***-stroke a surface stroke. Anyway, we're focusing here on an IM... 1. I feel no discomfort after a 25 fly without a breath, especially knowing that the "breathers stroke" is coming next. 2. If my face was red, it was probably out of shame that someone might actually see me doing backstroke. 3. I had my best time in 4 years !!! So, please, tell me exactly at what point in a race, time or distance-wise, can I expect to encounter this O2 debt monster ?