Deep core activation (not just surface abs) Passing the dumbbell forces your transverse abdominis to fire — the muscle that: Flattens the belly Supports the spine Protects against back pain Lower belly strength without crunching The knee lift targets the lower abs safely, making it ideal if you: Avoid crunches Have sensitive neck or back Are rebuilding core strength after 40 ✅️ Improves hip flexor control (not dominance) Because you’re seated and slow: Hips work with the core, not instead of it