What’s the best abdominal exercise? Good posture! There are many ways we can work our abdominal muscles but they don’t function in isolation and do a lot more than just flex the spine. I put a quick 8 minute abdominal circuit together here that can be part of a larger exercise plan that should involve strengthening your abdominals in a standing position as well. Don’t forget the rest of your core including your back, hips, glutes, and pelvis.