Practice was challenging, and towards the end, my muscles felt super tired - weak, but good. I find that with the harder practices, my breathing speeds up, making it hard to keep my movements slow and steady. If breath leads and movement follows, it's difficult to keep a smooth, slow pace. Then, when I'm trying to focus on slowing down my breathing, I have trouble fine tuning the poses.
All of this makes me feel like I am moving to fast, but yet I need to keep up with the class. It makes it hard to know what I should prioritize.