Grab the dumbbell you want to use with your left arm and sit on the end of a bench.

Position your feet at slightly wider than shoulder width apart.

Place the back of your upper left arm on the inside of your left thigh. Put your right hand on your right knee for support. You will use your left thigh as a back rest throughout the movement.

Start the exercise with your arm fully extended and slowly curl the dumbbell up as far as possible using a reverse grip (palm facing down).

Squeeze your forearm, and then slowly lower the dumbbellback to the starting position.

Repeat for desired reps, and then repeat the same for your right arm.

Exercise Tips:

As a general rule you should always work your weakest side first. This is why most people would do the left arm first.

Keep your entire body fixed throughout the set, only moving your lower arm.