Is CrossFit safe?

Yes. I have just a little experience with CrossFit. I did a free workout at a local CrossFit location. It was obvious that the CrossFit certification was not created by a physical therapist or someone with a sound understanding of biomechanics, but it is great for burning calories. People enjoy it so they normally stick with it as well. It helps people raise their intensity which is what people often have trouble doing. I use CrossFit type workouts for that purpose. It focuses more on the anterior chain of the body so it should be supplemented with posterior chain exercises.