down4fun
Contributor
I just got home form a week at Innerpsace, a CCR event at Divetech in Grand Cayman. For the third year in a row DAN was there conducting field research on CCR divers doing deep dives. For the purpose of this study, deep was defined as below 230 feet. I was lucky enough to be able to participate in the study for the week.
We had some baseline info gathered such as ht, wt, body fat composition, written medical history, then had to do do as many push ups and sit ups as we could, and also had baseline blood drawn. Blood was drawn pre and post dives on days 1,3,4 and 6. The blood was being shipped out for another study looking at stress of decompression diving shown my the breakdown of materials in the blood (as i understood it).
After every dive we were scanned via TTE every 20 minutes x 2 hours, during this they would scan the heart at rest and then have us move various extremities contracting the muscles to see if the exertion pushed out any bubbles, then back to rest. They were looking for bubbles in either side of the heart and bubbles were scored 0-7 based on a scale that i cant remember the name of right now. 0 being none and 7 essentially a white out. The team was willing to share results with us and we were allowed to make changes based on our individual results.
I wanted to share my personal experience. At the start of the study I was diving a Shearwater predator set to 30/85. I have never had any niggles or DCS symptoms prior to this study. After my first two days of deep dives 330+ I had 3's and 4's on exertion at the 20 and 40 minute marks, that subsided and were clear by the two hour mark. (all right sided heart bubbles, no left sided bubbles ever for me). Based on that I spoke with Dr Pollock, who was running the study and he recommended extending my shallow stops. I then spoke to Bruce of Shearwater, who was also there, and he recommended changing the second number to a lower GF, say 70 or 75, to extend the shallow stops.
The second change I made was based off of a presentation the Dr Pollock gave the second night, where he talked about keeping your exertion level during deco similar to that of your dive. So if you are swimming lightly during your entire dive, then swim lightly at deco too, so that your perfusion rate is similar. I had always heard not to exert your self during deco. But what he said made sense. If my heart is working at a certain level during the dive and transporting gas at a certain rate maintaining that rate while off gassing made sense.
I continued to dive for four more days with dives in the the 200-330 range and one in the 450+ range and the results were my scans were now showing mostly 0's at rest and and 1's on exertion. I threw only one 2 during the remaining 4 days and that was my high score. So to me the results speak volumes.
The other thing i noticed is i felt less tired after the dives when I had changed my GF. I had always attributed my post dive "tiredness" up to being a relatively small female handling hundreds of pounds of gear. I now think at least part of it was post dive bubbles.
I realize that this was a very small amount of dives and data, but i think for me personally the results speak volumes. As getting out of the water as clean as possible is my goal.
We had some baseline info gathered such as ht, wt, body fat composition, written medical history, then had to do do as many push ups and sit ups as we could, and also had baseline blood drawn. Blood was drawn pre and post dives on days 1,3,4 and 6. The blood was being shipped out for another study looking at stress of decompression diving shown my the breakdown of materials in the blood (as i understood it).
After every dive we were scanned via TTE every 20 minutes x 2 hours, during this they would scan the heart at rest and then have us move various extremities contracting the muscles to see if the exertion pushed out any bubbles, then back to rest. They were looking for bubbles in either side of the heart and bubbles were scored 0-7 based on a scale that i cant remember the name of right now. 0 being none and 7 essentially a white out. The team was willing to share results with us and we were allowed to make changes based on our individual results.
I wanted to share my personal experience. At the start of the study I was diving a Shearwater predator set to 30/85. I have never had any niggles or DCS symptoms prior to this study. After my first two days of deep dives 330+ I had 3's and 4's on exertion at the 20 and 40 minute marks, that subsided and were clear by the two hour mark. (all right sided heart bubbles, no left sided bubbles ever for me). Based on that I spoke with Dr Pollock, who was running the study and he recommended extending my shallow stops. I then spoke to Bruce of Shearwater, who was also there, and he recommended changing the second number to a lower GF, say 70 or 75, to extend the shallow stops.
The second change I made was based off of a presentation the Dr Pollock gave the second night, where he talked about keeping your exertion level during deco similar to that of your dive. So if you are swimming lightly during your entire dive, then swim lightly at deco too, so that your perfusion rate is similar. I had always heard not to exert your self during deco. But what he said made sense. If my heart is working at a certain level during the dive and transporting gas at a certain rate maintaining that rate while off gassing made sense.
I continued to dive for four more days with dives in the the 200-330 range and one in the 450+ range and the results were my scans were now showing mostly 0's at rest and and 1's on exertion. I threw only one 2 during the remaining 4 days and that was my high score. So to me the results speak volumes.
The other thing i noticed is i felt less tired after the dives when I had changed my GF. I had always attributed my post dive "tiredness" up to being a relatively small female handling hundreds of pounds of gear. I now think at least part of it was post dive bubbles.
I realize that this was a very small amount of dives and data, but i think for me personally the results speak volumes. As getting out of the water as clean as possible is my goal.
