For many people, finding motivation to exercise is a challenge. Thankfully, there are Zombies chasing you.At least that's the approach of Zombies, Run! - one of more than 31,000 health and fitness apps on the market today, and one of the growing number of apps that use games to increase physical activity.Gamification is currently the popular trend for mobile fitness app makers looking to cash in to help people get fit. Whether or not it's the best way to exercise remains to be seen. Continued at MedicalNewsToday>>