HEARTTHROB Justin Timberlake is making sure he’s not shown up at the altar by his super-fit bride-to-be Jessica Biel.

The pop and movie hunk has embarked on his own regime to rival that of his future wife ahead of their summer wedding.

“Justin has put on a few pounds recently after working out a lot for movie roles,” says a source close to the star.

“But now with the summer in sight he’s back in the gym and working out harder than ever. He seen the effort Jessica puts in order to stay fit and looking healthy and he doesn’t want to go the other way. She’s inspired him to get fit again.”                   –SS