Chillen, is there an age at which is becomes more important to focus on one or the other for the average person? I don't mean someone who has trained a lot, but someone who hasn't trained at all or hasn't trained much. Say, the person who might be susceptible to fad diets and takes up walking every five years. The average guy.
Back on the topic of situps and crunches:
STANDING AB CRUNCHES FTW!!!