Iso Power Breathing
When I practicing isometric power breathing (chapter 3 in 7 sec to perfect body) I get headache when i breath out fully. I want be sure If I doing exercise corretly.
When I inhale maximally to my stomach tense my abs and hold breath and tensing for 7 sec. Then slowly exhale keep tensing and breathe out all air and suck my abs in and hold breath and tensing for 7 sec. After 3 reps my head get strange feeling.
Is the exercises practicing correctly?