You can use weight machines to tone your inner thigh muscles, which are called your adductors. The adductor muscles include the adductor magnus, adductor longus, adductor brevis, gracilis and the pectineus. The adductors are responsible for bringing your legs closer to the middle of the body and stabilizing your hip joint. Therefore, when using an adductor weight machine you will be squeezing your thighs together against resistance, which brings them closer to the center line of your body.
Sit on the adductor machine with your inner thighs touching the pads that you will push against. Place your feet on the foot rests with your knees bent, or straighten your legs if the machine is built that way. Put your back against the backrest. Hold the handles located on the side of the machine. Relax your shoulders.
Adjust the range of motion of the machine by pulling the pin and opening your legs as far as they'll comfortably go. Replace the pin.
Push your thighs together until the pads touch. Exhale as you squeeze. Keep your back flat against the backrest. Lower the weight if you find yourself arching your lower back.
Open your legs slowly so the weight stack doesn't clang. Stop right before you reach the full range of motion. This is one repetition.
Do two sets of 12 to 25 reps if you want to increase the muscular endurance of your adductors. Do three sets of eight to 12 reps if you want to increase the size of your adductor muscles. Doing a smaller number of reps will increase your maximal strength but not the size of your muscles, according to the National Academy of Sports Medicine.
Select a weight that will tire your muscles on your last repetition. Lower the weight if you cannot complete your entire set without needing to rest between reps or if you break form by arching your back or lifting off of your seat. Raise the weight if you could do even one more repetition than your target.