"We are in the business, you and I, of changing lives. If somebody comes into your gym and leaves a month later, they have not changed their life."

Two-Brain founder and gym owner Chris Cooper said that, and  if you're a coach, trainer or fitness entrepreneur, you know it's true.

So how do you measure "lives changed?" And how do you make greater changes in the lives of clients? The key: increasing retention—or length of engagement (LEG). The longer you keep clients, the more their lives will be changed. And your gym will benefit, too.

To help you, Chris has a simple way to track length of engagement, as well as tips for increasing it. 

Listen, take action, change lives and build a thriving business.

0:41 - Changing lives through retention

6:23 - Driving retention up

14:27 - Tracking metrics and calculating LEG