In some cultures in the Northern Hemisphere, the astronomical March equinox (varying between 19 and 21 March) is taken to mark the first day of spring, and the Northern solstice (around 21 June) is taken as the first day of summer. In other traditions, the equinox is taken as mid-spring.
Circulation problems that cause dizziness. You may feel dizzy, faint or off balance if your heart isn't pumping enough blood to your brain. Causes include: 1  Drop in blood pressure.
A rapid decrease in your heart rate can occasionally cause you to become dizzy or even pass out, which is why you must follow proper cool-down protocols,even if you want to bring the rate down quickly. 1  Decrease the intensity of your workout as you near its completion, rather than stopping abruptly.