Do you know why human beings cannot run until they are approximately 2 years old? The answer is: the lack of balance. When you run you’re either airborne or have just one foot on the ground at all times, and your center of gravity, or balance point, is continuously moving forward. Half of your energy goes to propel you forward while the other half is actually to prevent yourself from falling down. 

In this second video about Emily’s cross training for her Chicago Marathon, Fayth focuses on exercises meant to strengthen stability and balance, guaranteeing Emily’s a stronger posture which will require a decreased level of effort so that her energy can actually go on the endurance required for the long run. https://video.be360.com/videos/182