INDIANAPOLIS — Pilates was developed during World War I to rehabilitate injured soldiers, and today it’s a popular method of fitness and strength training.

With World Pilates Day coming up this Saturday, we invited Kelly O’Brian, owner of Foundations Studio on the north side of Indy, to explain what Pilates is about and demonstrate some basic moves.

Pilates is a mix between yoga and calisthenics that works every muscle in the body, she said. It can be done on a mat, which is typically best for beginners, or a spring-based machine called a Reformer.

The practice is good for people of all ages, athletes and non-athletes, people recovering from and injury and those trying to prevent an injury, O’Brian said.

In honor of World Pilates Day, Foundations Studio is hosting a free-donation based class Saturday with all proceeds going to charity. Visit the website or call for more information.