how much abdominal pressure is created?

[Curious George]

Just a weird little question. When doing deads or squats specifically, I sometimes feel like I am going to shit myself. I know that there is a lot of pressure introduced in the GI tract, but how much? Has anybody ever seen a study done on the actual pressure in the abdominal wall? I know people who have blown weight belts out.

Take Good Care,

Cg

[archive_HULK1550]

i think there would be too many variables between different people to have a definate number, such as weight, height, form, ect. /infopop/emoticons/icon_confused.gif

[archive_Caligula]

We talked about studies done on this in some of my classes. I'm not sure about interabdominal pressure but I know we talked a lot about blood pressure. And some of those numbers were unbelieveable during a maximal squat. Somewhere around 750/400 at the extreme end.

http://www.anabolicfitness.net/images/caligula.jpg

"That Which Does Not Kill You Makes You Stronger"

Curious

[archive_Bjaarki]

Squats and deads - a lot of lifts, in fact - induce something like a Valsalva maneuver, which is attempted forced exhalation against the closed glottis. This raises intra-abdominal pressure and, as a result, blood pressure - thus the feeling of light-headedness. The Valsalva maneuver can also induce a feeling of wanting to urinate or defecate, just because there is so much pressure in the abdomen and thorax. Other things happen, too. Because of the great pressure, blood is temporarily trapped in the great veins, preventing it from entering the heart. Then, when the breath is released at the top of the rep, the pressure drops and the trapped blood surges through the heart, producing tachycardia and another BP spike. Your heart races, and you're shaking and trembling for awhile.

I don't know how much pressure is created during these lifts, but it is significant. Mel Siff, a well-known lifter and physiologist, would know. Email me, CG, and I'll get you his addy if you want. Thanks also for your post to the CS thread. You always say nice things, bro.

Bjaarki