Yes and no. Lifestyle has an impact on intelligence. You probably can't train yourself into a higher IQ, but you can many things that will dimish it (not sleeping well, bad nutrition, drugs, stress, etc.)
So if you've led a non ideal lifestyle in the past, you might be able to increase your intelligence by making less mistakes, relative to your current abilities.
So if you've led a non ideal lifestyle in the past, you might be able to increase your intelligence by making less mistakes, relative to your current abilities.