Committed to being healthier?
Set goals that are Specific, Measurable, Achievable, Realistic and Time-bound (SMART). Don't just say "I'm going to run more." Instead make a goal such as "Within 4 weeks, I plan to build up to running 3 miles at a time, 3 days a week."
Create a plan for what you are going to do and when you are going to do it. Add your workouts to your calendar just like any other appointment. Plan what you're going to do before you start each workout. Leave out your clothes so they're ready to go when you are. If you fail to plan, you plan to fail.
Maintaining an exercise journal and logging your workouts can also help you stay committed to your fitness goals. It will help you see what you've done and the progress you've made.
If you need some motivation to keep showing up, knowing someone is relying on you to workout with them can help. A workout partner can help you improve your form and may push you harder than you normally would if you were going it alone.
If you do the same thing day after day, you'll start to get bored. The more bored you get, the less likely you'll want to do it. Change the types of workouts you do on occasion or on different days of the week. Vary other aspects of your routine—the location, music you listen to or what you wear. VARIETY is the spice of life and will keep things interesting!