This workout is a nice progression from barbell moves to dumbbell moves to pure bodyweight moves. The push press is a great shoulder-builder, but it is super important to get a good grip on the bar, wrapping your thumbs around it and keeping your forearms vertical beneath it. The split squat is a great way to work on joint mobility and flexibility while building leg strength. And the squat thrusters with dumbbells are an absolute killer for full-body power. Just keep your elbows parallel to the floor or higher, and don't lean forward at any point. Think of the in-and-outs are a fantastic core move, just make sure you are working using your core muscles rather than momentum.