I will argue that all you need is three exercises to build great legs.
The first exercise is the king of all exercises, the squat.
The squat hits everything from knee to hips while secondarily hitting hamstrings and calves.
In fact, without strong, flexible calf muscles and Achilles tendon, full squats are not possible.
The second exercise is the lunge.
Hitting the inner thighs, outer thighs, groin muscles, calves, hamstring-glutes tie, and lower quadriceps tie-in, the lunge is a complete movement.
Finally, the last exercise is the stiff-legged dead lift.
This is a power movement that works the entire length of your hamstrings all the way up to the lower back.
It will also hit your entire muscle group surrounding the backbone, your traps, forearms, biceps, and calves.
Like I said with the lunge - wow - think you can handle all that? The movement: •Practice with an empty barbell to master movement first.
•Get into starting position by dead lifting the barbell up •With the barbell hanging in front of you, slightly bend your knees and hold that leg position throughout the movement.
It is stiff-legged not straight-legged.
•With an arch in your lower back, chest held high, your head up, and your shoulders straight; lower the bar.
•If you keep your shoulders square and chest out, the bar will not go much more than a few inches past the knees.
The key is to stretch the hamstrings, not touch your toes.
Let me repeat that - the movement is not to touch your toes.
•Once the bar is a few inches past the knees and you feel that strong tension in your hamstrings, pull straight back up.
•At the top of the movements, squeeze the glutes for a second before lowering the bar again.
•Again, it is stiff-legged, and with your torso square and tight, the bar cannot go much lower than a couple of inches past your knees (unless you are really flexible and strong in your hamstrings).
You must, of course, be the judge.
But, to my mind, if you are able to lower the bar much farther, than your back is not arched and you are dropping your shoulders.
•Also, by keeping your knees slightly bent; you protect your lower back.
You can get really strong on this movement.
Truthfully, after a session of gut wrenching squats, lunges, and stiff-legged dead lifts, I do not see how it is possible to do other leg exercise.
And why bother? Look at the portion of the lunge movement where you push back into the start position; it is identical to the leg extension movement - both the back and front movement.
Having done the full squat, do you really need the sissy squats or the hack squats or any other squat movements? Sure you could pile on 9800 lbs on the leg press machine and impress all the kids, but why? If you need variety, do 2 sets of 50 repetitions for the squat instead of the normal set/rep cadence.
That will challenge you.
Do these 3 movements twice a week or at 3 to 4 day intervals and you will need nothing else.