I understand.  Thanks George.

The reason that we suggest submaximal effort is that it seems to be adequate for producing a significant reaction. In addition, it may be difficult to apply maximum effort without also constricting other muscles, such as the buttocks or abdomen.

Tightening your abdomen is likely to have some effect on the lower pneumo tube. If you can't constrict your sphincter muscle without also flexing your abdomen, then you might wish to consider an alternative countermeasure, such as mental countermeasures or tongue biting.

Funny how a lot of jobs require some degree of eye-hand-foot coordination. All you need for this "job" is brain-butt coordination - leave your stomach out of it. 

When using the anal pucker, I read that the effort should be strong but not maximal.  Why?  I read that some people did it full strength and others only half strength.  Can someone explain?

Also, I noticed that when I constrict my anal muscle, I tend tighten my stomach muscle with it.  Will that cause the polygrapher to notice that I slowed my breathing on the abdomen tube?  Can someone explain?

Thank you.