How come i feel mighty dizzy after 35 minutes of treadmill?

Dizziness : Perhaps this is not indicative of a disease but just normal human physiology. When working out that long two things my happen: 1-heart rate may be reaching above target points 2-effective sweating and vasodilation. These two responses can lead to a reduced cardiac output and dizziness. It is important to stay well hydrated (gatorade may help). Check with your doctor to ensure you are safe. Be well.