I would start and get my heart to about 135 which is close to the lower end of my fat burning zone
. But less than 2 minutes in
, I start getting a piercing headache on the back, right side of my head. It lasts until I basically stop, lower heart rate, and move back to bike. Again, I can get my heart rate to 140 on the arm bike, really pushing it, and nothing happens. This is only happening on the elliptical. What in the world is the problem with using the elliptical?