The ol' power shrugs question. LoL This has come up a few times (at least once by me) so if you want to browse through the Mega 5x5 Thread you can probably find some more direct guidance from Madcow. Long story short -- it's like adding in anything, really. Add 'em in maybe on Mon. and/or Fri. Don't go crazy with them and don't make them a "foundation" movement or w/e, which means don't start trying to push 5x5 with them and burying yourself w/ volume & intensity shooting for bi-weekly PRs. Keep them as a relatively low-volume assistance lift. Then keep an eye on your fatigue. If the workload from the added lift starts to wear you down, best drop 'em or cut back. Remember, the main goal here is to make progress on your core lifts. don't let the shrugs interfere with that goal.