The light-headed feeling occurs because your body is letting you know you do not have the oxygen/carbon dioxide balance it is used to. This is also typical of the body’s reaction when you hyperventilate. This change in balance can occur when you use PowerLung because you are exhaling more efficiently than you have before and you are eliminating more carbon dioxide than in the past. It may typically take a week of regular use, for the body to adjust to the change in your breathing and also to the increase in oxygen you are bringing in as well as the more efficient way you are exhaling carbon dioxide.
Keep using your PowerLung. Stop when you get the light-headed feeling, rest (or hold your breath) for a moment and begin again. If it continues stop and wait 30 minutes or so and begin using PowerLung again. If the dizziness persists please contact your physician.