9. If you don't have time to complete a full exercise session

at least do SOMETHING physical. If you simply don't have time to get into the fitness center at all it's better to make sure you get at least some level of activity. You could, for example, walk up the stairs during your lunch hour and burn 100 calories in a ten-minute climb. The bottom line is that every activity burns at least a few calories (even watching television burns 75 calories per hour!), so even if you skipped your workout today you can still get active.