Hello, I went to band camp today for about 3 hours. We started working on leg lifts, planks and push ups, which I was struggling to do because I am not very physically strong. We went to get some water and started working on marching. After 5 minutes of this I started to feel very dizzy and I felt like vomiting. The main part I'm curious about is everything got very bright and I started feeling like I couldn't get enough air. After this I sat down for a bit I felt fine for the rest of the night. What was I experiencing and what caused it?