One of the most distinctive aspects of CrossFit is the focus on community. CrossFitters connect not only at the box, but online as well. Structure-wise, every box and instructor runs their own show, but most classes start with a 10-minute group warm-up, followed by strength and skill training (i.e. squats, lifts, pull-ups, etc). Then youâll get to the core of the class: the WOD. Itâs quite similar to high-intensity interval training (HIIT) and changes every day to keep the workouts fresh and challenging.