Any sort of physical activity is better than nothing. I gained some weight in the first month and a half after moving to the San Francisco (blame startup lunch

Any sort of physical activity is better than nothing. I gained some weight in the first month and a half after moving to the San Francisco (blame startup lunch and having no time to look for of a gym for that.) All I needed to adjust to drop the extra pounds was walk home every night. It's a longish walk (about 45 minutes) without a terrible difficulty level (not going through any of the hilliest areas), and yet that was more than enough to keep me fit and happy. Sure, walking alone won't make you gain a lot of muscle or incredibly performant in aerobic exercise, but it's definitely way better than just sitting on your ass all day and driving/shuttling home every day.