One type of leg exercise that can really work out multiple leg muscles simultaneously is the dumbell lunges. Dumbell lunges shape up your butts, build strength in your quadriceps and hamstrings, while also lending a clear definition to you inner and outer thighs. You can experiment with the dumbell lunge exercise, by either opting do it, while standing in one stationery position, or you could walk along a straight line while performing this type of lunges. 

In order to do this kind of exercise, you will need to hold each of your dumbbells in each of your arms, and then arch your shoulders backwards. Next you need to flex your chest wide, hold your head high, and look straight ahead of yourself. Take a huge step towards the front. This implies that your step should be long enough to have your left foot parked behind, and your right leg stepped ahead with a bent knee, such that your thigh muscles and calf muscles are at right angles to each other. 

Now gently go about bending your right knee a little further, so that your hips are pushed down a little further. Hold on to this position for a few seconds, before gradually getting back to your original standing position in a controlled manner, without any jerks. Do one set of 10 to 12 reps of this exercise, and then repeat another set of the same exercise on the other leg. If you want to test your strength further, it is a good idea to keep pushing down your hip further with each rep. This will also help with muscle toning, endurance training and increased flexibility. 

A couple of things that you need to keep in mind during this exercise, include that when you push your hip down further, your knees should not cross the level of your toes. Secondly, both your knees as well as your toes should be ideally aligned in the same direction. Also, the position of your knee should be exactly on top of the position of your ankle.

The next set of exercise that you can do to really build up those lean muscles in your lower body is leg extensions. Leg extensions are particularly helpful in shaping up the entire region of your quadriceps. If you work out in a gym, get seated on a leg extension machine. Now use your feet to hook your lower body to the padded bar in front of your legs. 

Adjust the position of your seat or the position of the padded bar, till you ensure that your knees are off the edge of your seat, and are bent along the edge of your seat, and your ankles are securely locked around the padded bar. The padded bar should not be on your feet or shins, but only on your ankles. Grip the handles on either side of your seat to prevent your hips from getting lifted off your seat, while performing leg extensions. Lift the padded bar attached to the weights through a pulley, until your knees are straight. Now lock your knees and hold the weighted bar for a couple of counts, then gradually release the lock and bring your legs all the way down to rest slowly in a controlled manner. Do one set of 10 to 12 reps. 

Armed with these exercises, you are all set to flaunt the perfectly toned and shaped up lower body lean muscles that you have always been waiting for.