We've received this question in various forms as of late. You want to look good while working out, but not like you're trying to look good. Nor should you be wearing some obvious designer workout gear that's most likely made for lounging at the juice bar. A trainer once told me that he preferred to workout in swim trunks because they're made for movement, cut closer to the body and the built-in lining keeps the boys for bouncing around too much on the treadmill. Plus, if you decide to take a dip, you're already dressed. As for the rest, invest in plain undershirts, a fitted lightweight sweatshirt and pack them all in a discreet, but durable bag.
37%: The percentage of adults who report they are not physically active.
(Source: President's Council on Physical Fitness)