During each exercise you should aim to maintain continuous strong tension throughout the abdomen and fore-arms/hands (fingers splayed). If you start to feel faint whilst doing these exercises it's probably due to inadvertently tensing your neck (which isn't a part of the exercise) and you should relax the muscles there immediately.
1. Drop into a squatting position, hands at waist, fists pointing inwards. Thrust both hands forward and down whilst strongly contracting the abdominal muscles. Slowly straighten the legs whilst raising the hands (held vertical with palms facing inwards) until a standing position is reached and the hands are above the head, then relax.
2. Stand upright, feet slightly apart, elbows fully bent so that arms parallel to body and horizontal with the fingertips touching the neck (palms down). Open arms to full extension (palms up), retract hands slightly then thrust them outwards whilst strongly contracting the abdominal and twisting so that palms face backwards. Rotate at shoulder to bring straight arms in front of body with back of hands touching. Turn palms to face each other and raise arms to vertical, then relax.
3. Stand upright, feet slightly apart, arms straight and horizontal in front of you, fingers spread. Come up on the balls of your feet, flex your back to push forward with abdomen, and bring hands towards body palm down (elbows out). Return to original position whilst tensing hands and stomach with a circular chopping motion of arms.
4. Stand upright, feet slightly apart. Cross arms over your chest and open fingers and tense stomach simultaneously. Move hands horizontally till in front of chest and slide them down the body while squatting. When the hands reach lower thigh level, move the arms to full extension directly to either side. Relax.
5. From a squatting position with hands to the side, push arms forward while tensing hands and stomach. Slowly raise straight arms above head level whilst standing up from squat. Relax.