Jennifer Lopez works up a sweat in her Preston High School jacket at the gym... a week ahead of resuming filming on Unstoppable

Jennifer Lopez Movie ‘Unstoppable’ From Artists Equity Returns To Filming Next Week; Don Cheadle, Michael Peña & Bobby Cannavale Join Cast As Amazon MGM Boards

Jennifer Lopez, 54, flaunts taut tummy in cropped sweater while dropping her teen Emme off at Sunday school in LA

Jennifer Lopez keeps it casual cool in cozy sweater and distressed jeans while jewelry shopping at XIV Karats in Beverly Hills