If you've ever wondered just how many calories you're burning with various activities like yard work, driving, climbing stairs, etc. go to this great website that will calculate it for you: http://www.caloriecontrol.org/exercalc.html.
Here are some examples:
Dancing for 30 minutes(fast, e.g., tango): 193 calories
Yoga for 30 minutes: 204 calories
Washing the car for 30 minutes: 173 calories
Vacuuming for 30 minutes: 88 calories
(All are for a 170 lb person.)
As you see, physical activity does not necessarily have to consist of exercise. It doesn't require fancy equipment or expensive outfits. But it does require you to keep moving. Sedentary work is among the most common reasons I see in my patients for failing to control weight and its associated lipoprotein patterns, like low HDL and small LDL.
If your work is sedentary, then a minimum of 60 minutes of physical activity per day is necessary to begin to correct weight-related patterns. If you gauge by calories burned, then a useful goal is 500 calories per day in physical activity--at a minimum.