I feel like the most effective arm exercise in the world is the push-up [1] and just because you are working out in a pool doesn't mean you have to skip them. Doesn't that make you happy? You can do a push-up variation using the side of the pool.

To learn how to do pool push-ups, .

Here's how to use the edge of the pool to work your arms:

• Place you hands on the side of the pool, just slightly wider than shoulder width apart. Your fingers should face forward.
• On an exhale, push your self up like you are trying to exit the pool. Keep your shoulders away from your ears [2] and don't lock your elbows [3]. Don't forget to use your abs.
• Inhale and slowly lower yourself back into the pool, stopping when your elbows are bent to 90 degrees.
• Don't touch the bottom of the pool. If you are in the shallow end keep your knees bent so you don't jump to lessen the work of your arms.
• Do two sets of 10 to 15 reps.

Fit's Tip: This is a great exercise for strengthening your arms to really power the "pull" of your freestyle stroke.

Source [4]