Dexter‘s Julie Benz wowed her social media followers with her rock-hard abs, as she donned a green bikini in a recent post. The star, who turned 54 on May 1, celebrated her birthday by proving that age is just a number. Julie, who also rocked a fedora hat and sleek shades in the post, enjoyed a poolside day with her friend and captioned the shots: “This is what strong looks like. 53 (almost 54) & 59.” © InstagramJulie showed off her rock-hard abs online Followers cheered Julie on and commented on her youthful appearance. One person wrote: “Wow, stunning ladies,” while another wrote: “This is what strong and gorgeousness looks like.” A third fan joked: “Ok we’re going to need to see some birth certificates for proof of age because this looks like a pic of two college students.” Julie’s fitness routine Julie is a huge fan of cycling to quickly increase her heart beat at a rapid pace. © Getty ImagesShe has an ageless appearance in her 50s She revealed to Self: “Indoor cycling …