Kashif Khan on Instagram: "Here’s what would happen to your body if you started doing reverse planks for just 3 minutes daily. The reverse plank might be the single most underrated exercise for fixing your posture and strengthening muscles that almost nobody trains. When you sit all day, your hip flexors tighten and your glutes switch off. This creates an anterior pelvic tilt, basically the reason so many people have back pain and rounded shoulders. And this one exercise can actually reverse the