Off topic, but yesterday I was thinking. When you hold a reverse kegel(the thing you do to force your urine out rapidly when you urinate), you can no longer hold a normal kegel. So a reverse kegel is somehow creating resistance against the kegel muscles.
So I then tried holding a kegel, and then at the same time pushing down internally to do a reverse kegel. The result is what felt like a very very intense kegel feeling. I noticed my blood heart starting beating quite forcefully(not at a higher rate, but with more force).
It seems like it could yield good results.