Quads cannot grow on squats alone. Not barbell squats, anyway.

While the basic back squat has a reputation as the World's Best Exercise, it earns that rep by working your posterior-chain muscles at least as much as your quadriceps. If your quads lag behind your glutes and hamstrings (or if all-out sets of squats give you the green-apple splatters in your Underoos), you have to incorporate something else to close the gap.

Traditionally, the leg extension plays the role of quad-catcher-upper. But it's probably the least-favorite exercise of the entire orthopedic profession, and, as a practical consideration, you can only do it if you belong to a gym that has a leg-extension machine. Even then you may have to wrestle the machine away from the grandmother doing sets of 100 with 10 pounds while reading back issues of Ladies' Home Journal.

So if you work out at home, or hate waiting in line for a machine, or belong to the 1 percent of American lifters who actually pay attention to their orthopedic surgeons, you need a real exercise for your quads.

And brother, do I ever have one.

Straight Outa Corinth

Let's get the obvious out of the way first: The sissy squat isn't for sissies. In fact, the name has nothing to do with the sexual orientation of people who do it, and everything to do with the mythical Greek king who inspired it – and who, let me tell you, was no poofter.

Sisyphus, as the legend goes, was the king of Corinth, and pretty much a total dick. He was greedy, he killed travelers and guests (the ultimate crime in Greek mythology), and he seduced his own niece. But what really put his balls in the wringer was the time he tried to cock-block Zeus.

Avid readers of Greek mythology know that Zeus, leader of the gods, combined a temper worse than John McCain's with the judicial instincts of Vlad the Impaler. Mess with him once, and he messed with you for eternity.

He sent Sisyphus to Tartarus, the lowest part of the underworld, and gave him a single task: push, pull, or carry a big stone up the side of the highest mountain, and leave it at the top.

Unbeknownst to Sisyphus, Zeus rigged the game so the former king could never actually reach the top with the stone. Each day he rolled it up as far as he could, and each day the gods arranged for him to fail, sending the rock rolling back down.

In its own way, weight lifting is a Sisyphean task – we lift weights day after day, week after week, year after year, and the weights never stay lifted. They always end up back where they started.

But that's not why the ultimate victim of "training to failure" has an exercise named after him. It's because of what all that work did for a certain part of his physique.

When you see Sisyphus depicted in ancient or modern art, he's almost always shown with bulging thighs, the finest pair of legs in ancient Corinth. He was the Tom Platz of classical mythology.

I saw my first rendering of Sisyphus some 50 years ago, and like any impressionable musclehead I was amazed at his leg development. The drawing I saw showed Sisyphus pushing with his back to the rock, digging his heels in for leverage.

I first heard about the sissy squat in 1960. An article in Joe Weider's Muscle Power magazine described the technique and mentioned the bodybuilders who used it – guys like Steve Reeves, Doug Strohl, Reg Lewis, and Monty Wolford.

I tried it and gained an inch on each of my thighs in less than three weeks. Even today, with all the options we have in our gyms and all the information that we didn't have in my youth, I consider it one of the most productive exercises you can do for your quads.

Bullying the Sissy Squat

The sissy squat isolates your quads better than any other barbell or dumbbell exercise. It does this by eliminating most of the involvement of your glutes and hamstrings. When you do it right, your heels will be above your toes, and your body, angled backward instead of forward, will form a straight line from neck to knees throughout the movement. That reduces the posterior-chain muscles to a supporting role, making them work with the rest of your core muscles to keep your body in that straight line. All the action is in your knee joints.

Here's the basic version of the sissy squat, using your body's weight for resistance. On any version, you'll need a block or step that's about two to four inches high, sturdy enough to support your weight, and won't slip out from under you in the middle of a rep. You can also opt for a rail or post you can hold onto for balance with one hand while you're getting the hang of it.

Body Weight Only

Set your heels shoulder-width apart on the edge of the block, with your toes on the floor and pointed straight ahead. Lean back until your body forms a straight line from neck to knees. Your knees will be bent slightly in the starting position. Place one or both hands on your hips, with one hand on a support for balance, if you prefer.

Lower your body backward as your knees bend. Descend as far as you can without losing your balance, then push back up to the starting position.

There's no need to straighten your knees at the top. Just do your reps smoothly within the best range of motion you can manage without losing the alignment of your torso and thighs.

You should feel a deep burn in your quadriceps after a few reps, but no pain in your knees. Do as many reps as you can with good form.

With Weights

You can use resistance three different ways:

• with dumbbells

• with a barbell held in the same position as the dumbbells

• with a weight plate held across your chest

I think it's easiest to use dumbbells. Start light, holding them with straight arms behind your hips.

As you progress, use weights that allow you to do about 12 reps per set.

Practical Applications

I've used the sissy squat in several different workout configurations.

Superset dumbbell and body-weight-only versions

Do a set of 12 reps with light- to medium-weight dumbbells, then immediately do a set with body weight only for as many reps as you can manage.

Use it as one exercise in a leg cycle:

Let's say on your leg day you normally do the following: squat, lunge, leg press, calf raise.

You could do a set of dumbbell sissy squats after the leg presses, or instead of them. Or you could do the sissy squats first, as a pre-exhaustion exercise for your quads. Or you could do them last, as a final kick in the butt before you leave the gym.

Use it instead of leg extensions

As I mentioned earlier, sissy squats are perfect for guys who work out at home, or who don't want to wait in line to use the machine at the gym.

Go Ahead and Throw a Sissy Fit

I hope I've convinced you that, despite its unfortunate name, the sissy squat is a tough, challenging, and extremely rewarding exercise, one that turns stick-like stems into rock-hard wheels.

Try it next time you work legs... if you're man enough.