The more we move, the better we feel – moving not only contributes to better physical health, but also a healthy mind and soul.  As we’ve heard in recent news, sitting is the new smoking – 86% of full time American workers surveyed spend their day sitting and when they do get up, 56% use getting food as the excuse to do so.  Finding and capitalizing on ‘active’ opportunities is key to bucking this trend but often we convince ourselves that if we don’t have at least X minutes, it’s not worth doing.  When it comes to activity this is not the case – 10 body weight squats every hour, a brisk walk around the office a couple of times, taking the stairs . . .it all adds up and makes for a good start.  Take note of how you feel and how much easier it is to focus once you start moving more frequently and do so consistently.  
Most people find that as they begin to engage in activity, they are more motivated to find time to be active. The next hurdles they encounter are 1) what to do? And 2) staying consistent.  In terms of what to do, FITs movement recommendations, included below can help as a guide to scheduling an active week with optimal exercise stimulus to aid you in achieving your goals:
Phase 1: Get Moving
6-7 days a week of low level activity
Walking, taking the stairs at work, playing with kids, gardening, youtube yoga session, etc.
Frequency: every day
Duration: 10-60 minutes
Intensity: Low
Phase 2: Keep moving, Add exercise
2-3 days a week of strength and/or power training
Ground based, multi-joint and large muscle group centric exercises which focus of full range of motion and connective tissue hypertrophy prior to adding load
Frequency: 2-3x
Duration: 20-60 minutes
Intensity: Moderate to high
Phase 3: Keep moving and exercising, Add intensity
2-3 days a week of metabolic training (intervals)
Frequency: 2-3x
Duration: 5-20 minutes
Intensity: Moderate to high
I have listed these in phases that build upon each other but if you are keen, they can also be introduced all at the same time.  If you are already doing phase 2 but not phase 1 or 3, try adding one or both and see how much better you feel for doing so.
Once you have committed to your movement plan, schedule it into your day rather than just expecting it to happen because you wanted it to happen.  Set a timer at your desk that goes off every 50 minutes, block 20 minutes out on your schedule for a walk, set your alarm 30 minutes earlier to fit in a youtube yoga session . . .simply put, if it is not on your calendar, it is not going to happen.  
Bear in mind, forming a habit is a daily task. In order to keep yourself motivated when days get tough, here are a few things to think about:
•Ask yourself: “How will I feel if I do this?” “How will I feel if I don’t do this?”
•Think of the long term.. Think about how your life will be different or how differently you will feel a year from now
•Consider who is looking up to you as an example or role model and ask yourself if you are living the role you would most like them to model
•Not every day is going to be a great day but knowing you have taken one step more towards your goal, you have automatically WON that day
Life is busy and too often taking care of ourselves becomes one more task on an ever growing list.  It is easy to forget how much better we feel and how much easier life is when we refill our proverbial tank.  Start small – 10 minutes today is 10 mins more than you gave yourself yesterday.  Build on your successes.  Keep at it.  When you are ready for more, look to the movement guidelines to figure out what you might be ready to add.  Before you know it, you will have ‘quit’ the sedentary lifestyle just as a smoker quits smoking and you will feel the difference.
Resources:
http://www.forbes.com/sites/jasonselk/2013/04/15/habit-formation-the-21-day-myth/#4ac3eed56fedhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3527832/
http://www.juststand.org/portals/3/literature/SurveyIndexReport.pdf