Cardio Circuit, Exercise 1: Fast Alternating Punch
Sit with your feet slightly wider than shoulder-width apart and with an upright posture.
Hold light dumbbells (or weights of your choice) up at your chin in a "fighting position."
Without locking your elbow, extend your left arm forward to throw a punch, and rotate your hand so that the palm is facing downward at the end of the movement. Then bring your hand back toward your face.
Punch with your right arm, then bring your hand back toward your face.
Alternate as quickly as you can for 15 seconds.
Take a 15-second break, then go to the next exercise.