Hollywood Abs by Alain Gonzalez ebook download in PDF format (.pdf), or read online for free! This is my 15-minute core circuit that I do a few times per week. All of my workouts incorporate resistance bands and a TRX suspension system, which do a great job at increasing core strength; however, I like to incorporate some direct training to increase functional strength, help prevent back pain, and improve my posture. I designed this routine to include a variety of core exercises including weighted and non-weighted movements, isometric holds, and compound exercises to ensure I hit all aspects of my core. Give it a try and let me know what you think.