I am saying 40 minutes a day is an absolute minimum sufficient for simple maintenance tasks (aka walking, cooking healthy meals, etc) and a far greater amount of time is required to actually accomplish anything meaningful, let alone novel or groundbreaking.
I am just speaking from experience. I can go on about these for days. I do exercises that keep my posture decent despite sitting all day. Takes a minimum of 15 minutes (3 sets of glute briges, 3 sets of planks, 3 sets of stretches, neck stretches, etc). There is NOTHING that "atomic habits" works for.
