Dizzy After Running On Treadmill Why Did I Pass Out - I Was Running On A Treadmill Very Hard Yesterday In A Gym. After About 20 Minutes Uphill?

Why did I pass out - I was running on a treadmill very hard yesterday in a gym. After about 20 minutes uphill? - dizzy after running on treadmill

I ran so hard yesterday on a treadmill at the gym. After 20 minutes of ascent to run my heart was about 167 (I 30). I knew that I was, but stopped, I jumped on the edges and had a little water - and then I began to dizziness, heard music is gone, and my goal was to come and go. I managed to stop the tape and thought it would be down and rest. The next thing I knew he was awakened by three species. One lady told me that I stumbled on the treadmill and had my head (still painful). I was completely and then click OK. What could happen? Anyone with similar experiences? Thank you.