DES MOINES, Iowa--(BUSINESS WIRE)--As summer kicks off and we enter the second half of the year, are American workers as financially and physically healthy as they think they are? According to new research from the Principal Financial Well-Being IndexSM: American Workers, employees are feeling optimistic about their physical and financial health, and see a connection between the two. Only 4 percent of workers rated themselves as physically unhealthy, and over half of workers (52 percent) believ