Tillbaka till Fysiologi
Seven Sambas
Static apnea measurements

text: Sebastian Naslund

HOW TO STOP? I have several times had samba or blackout during static competition. My will to hold my breath blocks out all the uncomfort and the signals of low oxygen and high carbon dioxide. I also focus so much on relaxation that I don´t "wake up" in time.

PURPOSE

This is the second apnea measurement with the ambition to find out when to stop. Read the previous. Since this game is all about coming as close as possible to ones limit (read: unconsciousness) I felt I had to go to this limit . I decided to actually explore the border to samba - several times in order to find out the signs of low oxygen. And yes, this is inspired by the "fattah-attitude".
Jump up and down - hyperventilate deep for a minute - empty your lungs - hold your breath. And please, if you do this yurself, sit down on something soft.

I do believe that this is something that will cause no longterm injuries - but there are no guarantees. It will show you - if nothing else - that a BO is quite easy to have. Before these seven breathholds below I had three warm-ups - on the third I fainted. After this I did less of the "jumping up and down" before hyperventilating. (From the fourth I did no jumping at all). The contractions, we know, are influenced by the rising carbon dioxide. Thus they mainly tell me how much I ventilated before breathhold. By hyperventilating I make sure that the symptoms of carbon dioxide does not make me terminate my breathhold before I suffer hypoxemia.

I have measured:

- Time (minutes and seconds)
- Oxygen saturation in the blood
(circulation from the heart).
- Pulse 		RED - marks first breathingreflex.
The oximeter was a very expensive one called "Engstrom"
My goal was to hold my breath to the limit - and stop just before LMC.
(Check terminology here)
Time
one
two
three
four
five
six
seven
"a typical"
oxy
pulse
oxy
pulse
oxy
pulse
oxy
pulse
oxy
pulse
oxy
pulse
oxy
pulse
oxy
pulse
0.00
99
92
99
95
99
110
99
84
99
85
99
66
99
89
99
89
0.15
96
67
97
75
95
91
98
84
98
81
98
81
97
80
93
81
0.30
79
57
84
65
71
67
96
75
97
73
97
70
87
68
88
73
0.45
67
56
71
68
57
63
91
69
93
64
92
67
82
62
83
65
1.00
64
48
61
71
47
61
85
68
89
63
87
71
77
63
74
62
1.15
54
44
51
67
46
50
79
73
83
63
82
66
70
57
64
60
1.30
47
38
47
60
41
41
71
71
78
69
75
66
68
61
54
57
1.45
36
32
44
51
39
40
64
68
71
65
69
73
61
53
49
51
2.00
tiny LMC
36
43
LMC
59
62
65
67
62
68
55
47
43
46
2.15
LMC
memory lost
55
61
60
62
57
63
49
42
38
40
2.30
51
49
55
58
53
58
sway
2.45
45
46
50
56
48
59
3.00
41
35
44
47
41
46
3.15
dizzy - dark
42
41
twich, some
memory loss
twitch
heavy sway
CONCLUSIONS
We see here that LMC (in this subject) occurs somewhere between 42-35%. We also see that there is a steady drop in oxygen levels. Since I in this test was looking for the feelings/thoughts right before the LMC I will describe them here:

At one point in all breathholds (usually close to 40%) I was asked to perform a task (for instance put your finger on your nose). I did this with full control and mental presence and usually within 10 seconds after that I terminated my breathhold. Sometimes I did not even remember what I did those last 10 seconds. This is one effect of hypoxemia and LMC - you erase your short term memory. This is why you often do not remember a samba.

1) One of the first signs were always that my visual capacities were dimnished - my sight was getting darker/less bright.
2) Numbness in my legmuscles (probably lactic acid)
3) At one point my ability to think clear thoughts quickly trails away - everything slows down and only one thought at the time is possible.
4) After that comes a warm feeling followed by a feeling of an internal swaying - like my conciousness was sitting on a slow motion flying magical carpet.
5) At one point I could actually see my thumb twitching (LMC) and I wrote this fact down right before total LMC - and I had no memory of writing it down.

To terminate the breathhold was never a conscious choice (only in the last one at 49%). It was usually something in my subconsciousness telling me that "shit, you are doing it again - start breathing you idiot".
The last 10 seconds are the difference between being fully conscious and a BO!
With the right breathing teqnique and a calm behaviour without unecassery movements I beleive that 2 or 3 of these breathholds could have been approved in a competition. Below is a rough calculation of the last seconds.
Visual & conceptual
malfunctions
Limited abilty to stop
No abilty to stop
LMC
Blackout
warmth - memory loss - twitches - sway
25 - 14 secs
13 - 7 secs
6-1
0 sec


Has low pulse anything to do with low oxygen? P. Lindholms (Karolinska Institutet 2002) thesis claims that "hypoxemia... provides an additional but not principal stimulus for bradycardi".
Thus low heart rate can be a sign of low oxygen.
My conclusion is; by studying your individual pulse you can get a hint of when to terminate a breathhold.

COMMENTS
Next person going for a world record I would suggest using the following:

Huge mask. Walkman stereo with calming music (classical baroc music is said to have an effect on us). Maybe some kind of hypnosis program that puts you in a deep state until its time to wake up. During the last minute I suggest your coach puts you a lot of questions that has to be answered with signs. Fail one or two - bail out. I also suggest you use a pulsemeter and stop when you reach the point when you usually are low on oxygen. And - since it is not officially forbidden - hook yourself up to a oxymeter and stop when you reach the levels when you usually loose it.

My question is of course - how much "help" should be allowed.

SUBJECT DATA
VC (5.9liters) (2002june)
RV (1.9liters) (2000june)
WEIGHT (70kg)
LENGTH (1.87 meters)
none-smoker

comments:
sebastian @ freediving.biz