I started working out a few weeks ago and i was on an elliptical which is the only machine i use that measures heart rate and my rate was up to 140 and went down to about 110 at the end of my 25 minutes. i have been exercising alot lately so i thought there might be a change. I got on it today and strted at a higher resistance and about every 4 miuntes i would do 90 seconds of intense exercise. My heart rate was between 79 and 103 the whole time. by the end of 23 minutes i was very dizzy and had to stop because i thought i might pass out. I had a bad headace when i was done. I dont know if this is normal, there are other factors though. I am under 17, i have had a cold this week, and i ate at 10 and exersiced at 2.
please let me know if this is normal