"I take a group of people. I find something that works for them, and I also mix it up," Zerling said.
She is a fan of multi-chain exercises, which involves the whole body for a total workout. Getting a partner helps most to stay with it.
The main idea is you want to do something that has little or no equipment, takes little time, and it has to be fun.
One partner throws the ball against the wall, the other performs an exercise, finishing in time to catch the ball.
"It's easy; you just need a wall for this particular workout, and again, you're getting those main exercises that work every single muscle group," Zerling said.
Dribbling and foot work for warm up, then it's push-ups, burpees -- the possibilities are endless. Play with kids, family or friends.
Zerling comes from an obese family and fought hard to get into athlete mode. She is the author of "Breaking the Chains of Obesity," and she is convinced people can succeed by doing mini bouts of exercise each day.
"There's a lot of evidence that if you split your workouts up into different segments you can get the same exact results as if you did it all in an hour," Zerling said.