Undo Sitting is a practical, evidence-informed mobility guide for adults whose days are shaped by desks, commutes, and screens. If long hours of sitting leave your hips tight, your back stiff, your shoulders rounded, or your body feeling generally sluggish, this book offers a realistic way to move better without a gym, special equipment, or an all-or-nothing workout plan. Instead of chasing perfect posture or promising quick fixes, it focuses on building a simple daily mobility system you can actually keep using. Inside, readers learn how prolonged stillness affects movement variety and why common problem areas often feel the strain first. The book explains the difference between temporary stiffness, deconditioning, and pain that deserves professional attention, then shows how to respond with short, repeatable routines. You'll find practical movement breaks for busy workdays, a five-minute morning reset, after-work mobility, and a longer full-body session, plus guidance on desk setup, screen habits, walking, and breaking up long periods of sitting. Clear, encouraging, and sustainable, Undo Sitting helps readers make regular movement an automatic part of screen-heavy life.