The build relies on a very simple circuit that relies entirely on analog electronics in lieu of the usual digital signal analysis usually employed for the job. It’s a barebones design that’s ...

Plus, did you know you can mix up your circuits depending on your goals? Whether you're trying to lose body fat or build muscle, there's a smart way to train. Scroll on to find out exactly how.

Since circuit training typically involves a variety of exercises, it works for multiple muscle groups in a single session.