Levi Johnston is back in Alaska after seven days traveling around the lower 48 states, including a visit to the ET studio, and despite his war of words with Sarah Palin, the 19-year-old says that there is no drama with Bristol Palin about spending time with their ten-month-old son, Tripp. Now, let the Playgirl workout begin!

Levi is prepping for a nude layout photo shoot in Playgirl, and he's got a tough personal trainer to get him in tip-top shape. Sorry, Levi - no bacon cheeseburgers!

"The more you come to the gym, the more you see results," says Levi.

Getting into "shoot shape," Levi endures a grueling three-hour workout looking straight out of a 'Rocky' movie, using the chin-up bar, a medicine ball, weights and resistance to get ripped.

"The first time I came here, the first week I hated it - I was puking, I was miserable," says Levi, joking, "This workout's horrible!"

Watch ET for more with Levi Johnston!