Using your phone’s GPS, CardioTrainer traces the route of your outdoor runs, jogs, hikes or cycling routes. It also gives you a bunch of different statistics, including the number of steps you’ve taken, your pace, how far you’ve gone and your elevation throughout your workout.

If even the thought of running in public makes you feel uncomfortable, the app also gives users the capability to log the indoor cross training activity you do in the privacy of your own home. Some of the options include treadmill runs and walks, stationary biking, aerobics, boxing, climbing stairs, dancing, elliptical workouts, swimming, yoga or weightlifting.

You can also set CardioTrainer to automatically upload your workouts to the app’s mother site, or post your stats to your Facebook or Twitter accounts. If you’re training for a marathon, triathlon or similar kind of strenuous outdoor physical challenge, this is an ideal app to have on hand, especially if you’re training by yourself. Through my own training experiences, I’ve found that documenting my workouts mean I’m more likely to stick to my schedule.

The interface shows a lot of information without feeling cluttered. Even better, the app’s customization options allow you to display only what you want to see. My favorite part about CardioTrainer is the app’s built-in music player, which gives users access to their playlists while exercising. During workouts, music volume will turn down slightly, and voice will report your progress — this way you don’t have to look down at a screen when you should be focusing on your training. What’s especially great about this option is that you can turn it off, if you like, or you can change the frequency of these little updates.

My only complaint with the app is its GPS tracking — it’s not as accurate as it should be. The app sometimes registers that I have run less or farther than my actual distance. If you’re banking on completing a certain amount of mileage, or if you’re having a tough run and can’t wait to finish, you can see how this might be annoying.

The app looks and works fantastically, but because it’s a bit unreliable, you might want to check out other similar apps.

[appbox googleplay com.wsl.CardioTrainer]