Punches make great arm exercises in the pool. They can also make effective aerobic workouts if performed rapidly for longer time. However, combining punches with upper body twisting adds a lot to the exercise.
While the main focus is arm muscles, this exercise also targets your core, and increases your flexibility. It's highly recommended to perform with aqua dumbbells or any other resistance.
Stand in the shallow end and hold aqua dumbbells with both hands. Bend your elbows and keep your arms by your side, in punching-ready position. Spread your legs out.
Twist your upper body to one side and punch one arm at a time (always with your far arm). Return to the starting position first and then repeat on the other side.
Focus on using your shoulder muscles to punch your arms on both sides.
Punch on one side with inhale and on the other with handle.