Article continues below advertisementJennifer Lopez is reminding everyone that age really is just a number - and she's got the abs to prove it.The multi-hyphenate star, 56, showed off her seriously toned physique in a steamy gym selfie, giving fans a peek inside her intense fitness routine. Taking to Instagram, Lopez struck a confident pose in front of workout equipment, rocking a cropped long-sleeve top and high-waisted leggings that perfectly highlighted her sculpted midsection.Article continues below advertisementSource: @jlo/InstagramJennifer Lopez showed off her toned abs in a gym selfie.