My dizziness(with one episode of full blown vertigo) came from not enough sodium in my diet. I have learned that I need to actually supplement sodium, especially, during intense training blocks and a lot of sweating with heavy water intake. I went through periods of dizziness... which made me feel like I was standing on a boat-dock. I saw drs, had bloodwork, etc... some thought it was low carb, some thought it was anxiety, low iron, chronic fatigue, stress, diabetes, etc... I went around in circles for a couple of years. I eventually realized, with my own experimentation, that I needed extra sodium. I eat very healthy with no processed foods. Mix that with heavy sweating and pounding a ton of water.. BOOM, I had nothing in my body left which lead to all of those symptoms.