Found these tips for staying motivated in an article from Mayo Clinic. A review is always good for when we get off track.
1. SET GOALS
Start with simple goals and progress to longer range goals. Make goals realistic and something you can achieve. It is easy to give up if you set goals too high.
2. MAKE IT FUN
Find sports or activities you enjoy, then vary the routine. If you're not enjoying your workouts, try something different. Join a volleyball or softball league. Take ballroom dancing. exercise doesn't have to be drudgery and you are more likely to stick with it if you are having fun.
3. MAKE PHYSICAL ACTIVITY PART OF YOUR DAY
It is hard to find time for exercise, don't fall back on excuses. Schedule workouts just as you would any other important appointment. Take stairs, walk up and down sidelines while watching kids play sports, pedal a stationary bike or do strength training while watching TV.
4. PUT IT ON PAPER
If you are hoping to lose weight, boost your energy, sleep better, manage a chronic condition - write it down. Seeing the benefits of exercise on paper may help you stay motivated.
5. JOIN FORCES WITH FRIENDS, NEIGHBORS OR OTHERS
You're not in this alone. Invite friends or co-workers to join you when you exercise. Work out with your partner or loved ones. Play soccer with your kids. Organize a group of neighbors to take fitness classes at a local health club.
6. REWARD YOURSELF
For a few minutes after each workout savor the feeling exercise gives you. This type of internal reward can help you make a long-term commitment to regular exercise. External rewards can help, too. When you reach a goal treat yourself to a new pair of walking shoes or new tunes for your player or device.
7. BE FLEXIBLE
If you are too busy to work out or simply don't feel up to it, take a day off. The important thing is to get back on track as soon as you can.