Kegel exercises (pronounced "Kay-gill", in case you ever actually have a
conversation about them) were invented to give women better bladder
control. They have a number of useful advantages in sex. In women, they can
help tighten the vagina, particularly after childbirth. The muscles can
also be used deliberately during intercourse to stimulate her partner. They
have a variety of uses for men. As I already mentioned, they strengthen the
muscles used in seminal retention, making that technique more effective.
They can make ejaculation more powerful. This may increase male enjoyment
somewhat and female enjoyment if she is sensitive to it. Deliberate
twitches during intercourse are also useful for males. Knowing how to force
relaxation of the muscles can help maintain control and prevent premature
ejaculation, as well as relieving the muscle cramps that can occur from too
many ejaculations in succession.
Kegel exercises might indeed help with [increasing the force of
ejaculation]. Here is how they are performed by males. First you have to
learn to consciously control the muscles. One way of doing this is to use
them to stop and start urination repeatedly. When you have an erection,
contracting them causes it to move, making them easy to identify. Once you
have the muscles identified, there are three types of exercises to do:
1. try contracting the muscles and holding them that way for a slow count
of ten. You may not be able to last that long at first, but that is why
you are exercising.
2. force them to relax by bearing down as though you were constipated and
trying to force a bowel movement.
3. twitch (contract and release) the muscles as fast as you can ten times
in a row. I find that it works well to alternate each of the first type
with one of the second type. I don't recall how many of these are
recommended. Something like ten of each to start, eventually working up
to a hundred.
In addition to the possibility of increasing the force of ejaculation,
these may increase the number of contractions and the total enjoyment. The
same muscles can also be used to reduce the amount of semen in an
ejaculation by contracting them as hard as possible during it. This leaves
a less than satisfied feeling, usually accompanied by an urgent desire for
another orgasm 10 to 20 minutes later. This can be useful if your partner
wants more sex than you do. Supposedly, increasing the strength of the
muscles can increase this effect to allow quite a few orgasms in a row.