The Baggies started brilliantly before fading into an eighth-place finish and goalkeeper Foster wants the same to occur in 2013/14 in order to give the West Midlands club the best possible chance of another top-half ending.
"For the first third of last season we caught a lot of people off guard because of how fit we were," he told the club's official website.
"That's exactly what we'll be trying to do again this season. We make no secret of the fact we're doing long double sessions.
"This is probably the leanest I've been in my whole career. I'm feeling good and I'm feeling strong.
"I haven't struggled in training so far and I'm looking forward to seeing what pre-season brings. I can't wait for the start of the new season."