Machines are more common in CrossFit than ever. Here’s why that doesn’t automatically mean less fitness — and why context matters.

Most people think they’re training in Zone 2, but they’re nowhere close. This guide breaks down what Zone 2 actually is, why “feel” lies, and how to find your real Zone 2 using heart rate, Critical Power, and simple testing so you can build a better aerobic engine for CrossFit, HYROX, and life.