You can find this exercise on page 11 of the book Synergistic Golf.
Exercise Type: DB STRENGTH
Exercise Category: HEAD - NECK, POWER PRODUCTION, SHOULDERS, STRENGTH
Stand with feet hip distance apart holding 3-5-8lb dumbbells directly in front of shoulders with palms facing inward toward each other. Inhale to prepare. Exhale alternating controlled punches or lifts with arms overhead keeping palms facing each other. Complete 20 repetitions (10x each side). Focus on breathing and strong back and posture throughout exercise.