The Reformer is a full-body workout

Working out on a Reformer is a full-body workout. You will be working a lot of small muscles that you may have never worked out before. Needless to say, your core is going to be engaged throughout virtually every exercise on the reformer.

You will likely be doing some exercises that work your legs and core more and others that hit your arms and core more aggressively.

For example, the footwork on the foot bar is more leg heavy whereas exercises like bicep curls and airplanes using the straps can isolate your arms a bit more.