Is sitting really as bad as people say?

The strong version — that sitting is equivalent to smoking — is an exaggeration. What holds up is that prolonged uninterrupted sitting is independently associated with worse metabolic and cardiovascular outcomes, and that this is only partly offset by a workout elsewhere in the day. The good news is that the fix is modest: breaking up sitting every 30 to 60 minutes with a few minutes of movement appears to capture most of the benefit, and total daily movement matters more than any single session. So the target is not standing all day, it is not sitting still for three hours at a stretch.