Those references don't seem to address my question about effort having an effect on intelligence. My question isn't about the heritability of intelligence, but whether effort (that is, training) can enhance one's intelligence. Let me explain with an analogous question:

Does athletic training increase athletic ability? In terms of strength, flexibility, aerobic fitness, speed, perception, assessment, reaction times, specific skills, strategy?

Do believe that mental exercise has no effect whatsoever on mental ability?

That would be contrary to everyday experience, and studies showing that a lack of stimulation (i.e. mental exercise) retards cognitive development. e.g. that the visual system does not develop without stimulus; that the speech centers do not develop unless exposed to speech within the window (closes at around 7yo).

EDIT interesting: "Breast feeding makes a huge difference, about 7 IQ points." http://www.amazon.com/Factor-Science-Evolution-Behavior-Inte...

Give me numerical proof

...Of what? Do you mean something like this?:

http://www.amazon.com/Bias-Mental-Testing-Arthur-Jensen/dp/0...

http://www.amazon.com/Factor-Science-Evolution-Behavior-Inte...