One thing that most people complain about while working out is light-headedness, this often occurs in the middle of a workout if one hasn't eaten or hydrated enough pre-workout. Dehydration takes place when the body loses more fluid than it gets, and the most common cause of water loss from the body is excessive sweating. Also not allowing yourself enough recovery time in between workouts can result to feeling lightheaded, this means you simply get short of breath, concentration level might drop significantly, and you might have difficulties standing on your own. To fix the aforementioned, stop whatever vigorous activity you're doing, and drink enough water to compensate for the lost water, then lie down in a position where the head is level with the heart, this allows more blood flow to the brain, causing the feeling of faintness to go away. And the water helps to hydrate the body again.
