Leg curls are a strength training exercise that primarily targets the hamstrings, the muscles located at the back of the thigh. This exercise is typically performed using a leg curl machine, where the individual sits or lies down and curls their legs towards their body against resistance. Leg curls help improve muscle strength, flexibility, and overall leg function. They are often included in fitness routines to enhance athletic performance and support activities like running and jumping. Proper form is essential to prevent injury and maximize the benefits of the exercise.