Ok, so we don't have a lot of trees or grass and there are tons of people and pollution and every day can produce new obstacles BUT.... the city provides lots and lots of  free exercise.

Every time you take the subway you climb up and down stairs. Since you don't have a car you must walk blocks and blocks every day to get to your destination. If you live in a walk up apartment you are getting free exercise each time you leave or return home. You are constantly carrying things all over town, building your strength. Every where you turn there is a street to walk, stairs to climb and a deli with a salad bar.

Sure, we tend to eat on the go here on a daily basis but you can still find healthy options. A law was just passed banning trans fats in NYC restaurants. If you live in NYC or a big city, use those free exercise options made available to you such as the stairs vs the elevator and make those healthy choices that are right in front of you!