Fitness apps are nothing new, but getting motivated to work out can often be the difficult part. That's where the emerging genre of interactive fitness apps come in. These apps use your activity to tell you a story, motivate you, and make your workout seem more like a game. There are plenty of them out there, but we went ahead weeded through them to find the apps you definitely don't want to miss.

If you're having trouble getting started, these apps are a great place to get motivated.

READ NOW: The best interactive fitness apps that android has to offer

1. Runtastic Stories

Runtastic stories

We've talked before about how Runtastic is a fantastic fitness app if you're a runner. It's filled with enough features that you may have missed Runtastic stories within the app. Story runs are considered a premium feature for the most part. Each run is a different length, generally between 30 and 40 minutes. During your run you will see how long you've been moving, the distance traveled, and your average pace. Since it's part of a larger app it isn't quite as interactive, but you can post your workout to facebook, and integrate a heartrate monitor to the app.

With over a dozen stories spanning several genres, you've got plenty to listen to on your run. While there are a few free stories to run to, most of them cost $0.99 unless you buy into premium Runtastic membership for $4.99 a month.

Download: Runtastic (Free)

2. The Walk

The Walk

The Walk is far more of a game, than it is a fitness app. You are an agent who has been asked to help save the world. As you walk—and all you ever need to do is walk, you will unlock sound clips which tell the story. The story is broken into Episodes, and each one has checkpoints, collectible items, the ability to choose a route, and even achievements. If you've had your phone closed and you reopen the app, you'll be notified of how many steps you've taken and how long you would need to keep walking to finish out the current mission.

The story is seriously engaging, and when you get caught up in it, it's easy to let time slip by so you can finish the entire mission in a single go. The Walk is $2.99 and entirely worth it.

Download: The Walk ($2.99)

3. Battlesuit Runner Fitness

Battlesuit Runner Fitness

Battlesuit Runner is definitely the most sci-fi inspired app on the list today. Your character in this game is Deltasuit, a member of a group of Battlesuit runners. The interface during your run is fairly bare, giving you a readout of time, distance and pace, along with your armor and iridium.This one becomes interactive because at certain times you'll be asked to make a choice in the story by either speeding up or slowing down your pace.You'll encounter enemies As you go along you'll encounter enemies who will drop iridium—the in-game currency used to upgrade your suit in between missions.

You can get a free version of Battlesuit Runner with the tutorial and 3 additional missions, or get the full version for $0.99. This app is affordable, geeky and a step in a different direction than any of the other interactive fitness apps we've found.

Download: Battlesuit Runner Fitness (0.99)

4. Zombies, Run!

Zombies, Run!

Zombies, Run! is probably the most popular app here today, and for good reason. There are currently four seasons worth of missions, as well as a paid version of Zombies, Run! for 5k training. The app will hit you with chunks of the story as you move, each piece coming every few minutes. At times, you'll be told to run and you'll hear the zombies chasing you which is definitely a motivator. As you travel along, you'll automatically pick up items which can be used to improve the town after each mission. During mission you have a counter that tells you how far you've gone, your pace, has a counter of in game items, and a status bar for how far you've gotten in the mission.

Zombies, Run! is fantastically fun and captivating. It makes you want to keep going, and because there is so much content it's very easy to. You don't even need to run, you can take the game at your own pace since missions are timed, and not based on how fast you move.

Download: Zombies, Run! (Free)

There you go, four of the best interactive fitness apps on the market today. Whether you're looking to just amble along, or you're training for a run, these apps can definitely make fitness more like a game than work. So which interactive fitness apps are up your alley, or which ones did we miss out on? Let us know in the comments!