Of exercising and time

I was just thinking about something the other day.

You see, we save a lot of time when the public transport is efficient, or even better if we own a car. So much time saved from travelling around, that we can devote the time for other activities, especially work/study. But you also see, these days, people also have to set aside time to workout/exercise/head the gym etc. And then you think...

People back in the days when cars were non-existent, riding a horse is only for the rich and the royalties. So people walk. And so the people spent a lot of time walking, but they didn't need to set aside time to exercise, because everyday, they walk a lot.

So, effectively, the time we save from walking to school/workplace, is used for exercising. Kind of right?

Why so lame...?