Riding in the subway, as opposed to hiking in the woods, allows people the chance to venture in the busy metropolis that is the densely packed inner city. Where busy passengers gaze around, they can feel the menagerie of the whole atmosphere as others come and go, rushing to their own destination. The fast-paced, adrenaline-filled periods when people squishing by each other and getting to their stations, as they try to catch the next train to arrive, calls upon more physicality than a simple hike in the woods. Stepping in to the train, the unintended bodily contact and the forced diminish of everyone's personal space as the people in the back desperately squeeze in fearing to be left behind, all accumulate to the sense of physical as Kate Braid puts it. Perhaps their use of the subway as their means of transportation may seem mechanical and far from physical, but the external contact that they get from their fellow train takers and the need to stay in balance when the train motions counts as a sort of workout as well.
I prefer the escalator just because its fun and because I can walk on that and still be faster than taking the stairs.
Watching a hockey game is cool but sweaty workouts always gives a sense of accomplishment.
More checking my e-mail than shovelling snow because Vancouver rarely snows.