How do Fitness blender trainers train?

Today, while watching a video by Tasha, I thought, Wow. But that's what I think every time I watch a Fitness Blender video. The trainers are healthy, athletic, strong, and agile, and I'm curious. I followed workouts on other apps for a while, but some trainers were really skinny (too defined) and others were very muscular, which I don't really like in a woman's physique. But the Fitness Blender trainers are spectacular, strong but agile and healthy. So I was curious. Are the workouts you follow exclusively Fitness Blender ones? Or do you add anything else? Do you go to the weight room? Are the weights you use the ones noted in the videos? Do you follow specific diets? Are there things that make a difference in this lifestyle?