1) "Women rate muscular men as sexier, more physically dominant and volatile, and less committed to their mates than nonmuscular men."
2) "Women indicate that their most recent short-term sex partners were more muscular than their other sex partners."
3) "Muscular men … report more lifetime sex partners … and more affairs with mated women." ("Muscular men were twice as likely to have had more than three sex partners than less-built types.")
4) "Men with moderate muscularity are rated most attractive." 
He said prior studies concluded a man's desirability was influenced more by his earning potential and commitment. His study found physical characteristics mattered more. 
http://www.slate.com/id/2170016/ , etc al
 ie, there's a sweet spot. it's not a linear 'more muscle' => 'more babes' (though many men don't seem to think nonlinearly)
 My opinion is that there's another variable. That a woman's own potential income influences where on the physical/resources desirability scale she is. In a society where women are either not allowed or have substantially lower incomes, earning potential (and commitment thereof) are prized in men. In societies with more equality, the hetero woman need not look to a man for resources and will seek out the physical beauty (hence the advent of the metrosexual). Really rich women have no need for earning at all, and will dally with commitment-less boy toys.