BURT LANCASTER / THE SWIMMER (1968)
Ostensible reason for shirtlessness: Like a salmon returning to its spawning ground to die, Burt's headed home, one swimming pool at a time.
Real reason for shirtlessness: Only one way to get people to see depressing art-house flick about crazy broken loser: Put Burt Lancaster in a Speedo the entire film.
Rehearsal/preparation: Incredibly good genes. (Lancaster was 55 when he made this movie.)
Cultural repercussions: 25-year-olds everywhere feel shamefully deficient.
Pector or Actor?: Four Oscar nominations, one win. At 55, he still looks like he could bench-press Kirk Douglas. Pector/actor!