Reverse curls and French curls are upper arm strength-training exercises. Together, these two exercises work your entire upper arm. The reverse curl targets your biceps, the muscles on the front of your upper arm, and the French curl targets your triceps, the muscles on the back of your upper arm.
The French curl and reverse curl are isolation exercises; they target one muscle group -- the triceps and biceps respectively -- and involve movement at one joint -- in this case, the elbow joint. The reverse curl involves flexing, or bending, the elbow, and the French curl involves extending, or straightening, the elbow. The French curl is a misnomer since it is an elbow extension exercise, not a curling exercise; it also is referred to as a skull crusher exercise.
Perform the French curl exercise lying on your back on a flat bench. Start with your arms extended, holding the barbell over your chest. Bend your elbows, lowering the bar toward your forehead. Stop before the bar touches your head and then press back up. Perform the reverse curl in a standing position. Grab the barbell with a shoulder-width grip, your palms facing the floor. Start with the bar in front of your thighs and curl it up toward your shoulders.
You do not move your upper arms during either exercise. The only movement occurs at the elbow; hold your upper arms, from your shoulder to your elbow, stationary throughout the exercise. Your elbows point toward the ceiling when you lower the bar during the French curl and they point toward the floor when you curl the bar during the reverse curl. Breathe in as you lower the weight and exhale as you curl or press the weight.
You can use an EZ bar or dumbbells instead of a barbell for either exercise. Although you do not need a spotter for the reverse curl exercise, you should have one during the French curl exercise. It is called a skull crusher for a reason. If you lose control of the bar, it can easily hit you in the forehead or nose. Doing a one-arm dumbbell French curl allows you to spot yourself with one arm while you work the other arm.