Unfortunately, this would be gender and/or location dependent. Great advice for daylight hours, but the society we currently live in makes it perhaps less viable for women in certain areas or countries, or even in general if it's a particularly socially deprived area.
Absolutely on board with the exercise thing though. I've taken to trying to waste time on an exercise bike - even an inexpensive one, or a normal bike mounted on a turbo trainer. I'm not expecting anyone to bang in speeds and times like Lance Armstrong on some special supplements, but a slow spin for longer periods of time is great fun... just get a good wide comfortable saddle!