Considering that one of Orlando Bloom's breakout roles was playing a blacksmith-turned-rogue pirate in 2003's Pirates of the Caribbean, it should come as no surprise that the actor enjoys working out in the water.

His fitness buddy, however, isn't necessarily someone you would expect.

During a recent appearance on The Late Late Show with James Corden, Bloom revealed that he sticks to an underwater training plan developed by big-wave surfing legend Laird Hamilton. (Bloom has also trained with New York Knicks center Joakim Noah).

Bloom and Hamilton's "pool training" is no joke—the two use 50-lb dumbbells and, while holding their breath, carry them back and forth in the pool for as long as possible. This "deoxygenates your blood," says Bloom, and stresses your body out for an even more intense workout.

And while we'd recommend taking a few precautions when doing underwater workouts that require you to hold your breath (like having someone spot you), you can definitely do these 10 exercises for swimmers and 5 sand workouts safely on land.

Check out the full clip from Bloom's appearance on The Late Late Show with James Corden in the video below: