After birth
What people most often bring here: an abdomen that still feels "open" down the midline (diastasis), a little leaking when coughing or jumping, a heavy or dragging feeling in the pelvis, and difficulty getting back to exercise because your body feels unstable.
Pelvic floor training after birth reduces incontinence, particularly when it is delivered with structured support rather than an instruction to "do your Kegels". We should also say this plainly: there are not enough data to be sure the effect holds beyond one year after birth, so this is something to keep doing, not something you finish.
On returning to running: the widely used guidance suggests a minimum of 12 weeks postpartum before any running — and even then only after passing strength and load-tolerance testing. After a caesarean it is often longer, because the incision needs time; the guidance does not put a number on it, so we judge that individually alongside your obstetrician. A diastasis does not automatically mean you cannot run; what decides it is whether you can already control abdominal pressure and take load through the abdominal wall while you run.