We all go through phases. One week we're all about fitness, and working out is fun and easy. But somehow, even just a week later, we fall into a slump, and hitting the gym or going for a run is the last thing we want to do. When you lose motivation to get out and exercise, try these 10 tips:

1. Schedule it into your routine

Each Sunday, look at your schedule for the week and write in when you will work out. Whether it's the first thing you do when you wake up, or the last thing you do before you go to bed, schedule it in. Have a backup plan in case something unexpectedly comes up; because we all know how often that seems to happen.

2. Sign up for a class

Once you've signed up and paid for a set of classes, it becomes easier to make it to the gym. The classes are already mapped out for you so you don't have to decide what to do each time you work out, and you've already made a commitment!

3. Go with a friend

Plan a time with a friend to go for a walk/run, go to the gym, play tennis, etc. Having a good workout buddy can help immensely when either of you are tempted to back out.

4. Get your clothes ready

If you work out in the morning, get your clothes ready the night before so all you have to do is put them on and go. If you like going to the gym or running right after work, pack your gym clothes in a bag so you don't have to stop by home first.

5. Get good music on your iPod

Especially if you're running for your routine, good music is crucial to staying motivated. Upbeat music helps you go faster and longer. Try listening to running stations on Pandora to get ideas of what music pumps you up!

6. Reward yourself

After a week or two of staying on track, buy yourself something nice or do an activity that you love. Buying a new pair of running shorts, a new bottle to carry with you or even going to a movie will give you something to look forward to when you are on the last mile of your run or the last ten minutes of your weights routine.

7. Sign up for a race

Go online. Find a race in your area. Pay for it. Even better, get a buddy or two (or 10) to sign up with you! (See tip 3). I hated running until I started training for and running races, now it's one of my favorite workouts!

8. Do something you are passionate about

If you like being outdoors, find activities you can do outdoors. Play tennis, basketball, soccer, racquetball, go for a swim, or even go dancing. These are all great ways to get your exercise in without feeling like you're exercising.

9. Have a more meaningful reason

Although wanting to look good in a swimming suit or fitting back into an old pair of jeans are good short-term motivators, that's what they are, short term. Find a reason that is more meaningful, such as being able to run around with your kids, or the feeling you will have once you reach your goal.

10. Have fun

Once you get in a routine, you will find that you start to enjoy working out. Give yourself a little time. Soon you will see that you can't go too many days without craving the gym or a nice long run