To train the hamstring portion (hip extension), you need hip extension with a wide stance. To train the adductor portion (leg adduction), you need resistance pulling you outward.

When people talk about leg strength, the conversation almost always starts and ends with the glutes and the quads. Squat depth? “Squeeze your glutes.” Deadlift lockout? “Drive your hips through.” While the glutes certainly deserve their crown as the king of posterior chain power, there is a silent guardian, a watchful protector lurking deep in your inner thigh: The Adductor Magnus.

As you descend into a squat, the adductor magnus prevents your knees from caving inward (valgus collapse). It keeps the femur in a neutral alignment relative to the pelvis.

So, the next time you are in the gym, skip the leg extension machine. Set up a wide stance. Hinge deep. And give a silent nod to the massive, forgotten giant on the inside of your thigh.

Why? Look at a deep squat. As you descend past parallel, your hamstrings actually slacken because they attach above the knee and below the hip. When the knee bends, the hamstring tension drops. However, the Adductor Magnus doesn't have this problem.