I've trained a lot of females over the years, from middle-aged housewives to centerfold models to Figure Athletes to television stars. In that time, I can honestly say that all females want the same thing: A great ass.

An ass is to a girl is what biceps are to a guy. You'll never find a person in either camp who doesn't want to develop that muscle group to head-turning proportions.

Indeed, every girl wants a harder, more shapely caboose. That's no surprise. What might surprise you, though, is the best way to build one.

Years ago I told guys to stop focusing on curls and put more effort into chin-ups and palms-up rows. It worked, even though most guys thought that curls were the holy grail.

Now, I'm here to show you the way to a steely, curvaceous ass. And it's probably counterintuitive to what you currently believe.  

Look Around

When it comes to building a hard, sexy body — or any body, for that matter — I derive my training methods from three sources:

1. Personal experience
2. Research
3. Real-world observations

I want evidence that something works. The first and most time-consuming way to learn what works is by training hundreds of different people over the course of years. The second place to look is research.

Problem is, there's very little reputable research pertaining to muscle growth and training. And you'd never find a NIH-funded study with the title "Training methodologies for maximizing the gluteus maximus in females."

So that leaves us with point 3: real-world observations. If you want to know what works, look for those who've accomplished what you're after. I think this is where most trainers fall short. If personal trainers spent as much time looking for athletic evidence of a great ass as they do dreaming up cockamamie exercises on a Swiss Ball, there'd be no need for a plethora of stretch pants.

Which female athletes have the best ass? That's easy: sprinters!

If you've seen the Olympic female sprinters on TV, or if you've spent time perusing pictures of hot female athletes on the Internet (I would never commit such a salacious act) you know what I'm talking about.

Not only do Olympic female sprinters have the best bodies on earth, they're also the fastest power athletes. Coincidence? I think not.

Are You Just Born With It?

Anytime you see a highly developed muscle group you've got to ask yourself: Did that development come from training, or did she simply choose the right parents?

With some muscle groups (calves, for example) genetics play a huge role. After all, if your muscle insertion point is very high you'll have a hard time building up huge calves because the muscle belly is short. This is where the saying, "Long tendon, short muscle" comes from, and it's why some people can never be professional bodybuilders.  

With the glutes, however, genetics play less of a role. Sure, your muscle fiber arrangement will determine how your butt will ultimately look once it starts getting more muscular, but unlike the calves, people aren't limited by having glutes with a long tendon.

In other words, the playing field is more even in the race for a great ass. That's good news!

Why do female sprinters have the best ass? Read on.

Muscle Function

The roles of the gluteus maximus are extension, lateral rotation, and adduction of the hip joint. Extending the hip is where it's at in terms of development because that action stimulates the most glute fibers.

Here's a quick refresher so you know what I'm talking about. When you walk, the joint action that takes place from the time you plant your leg in front, to it being pulled back as you propel forward, is hip extension.

This is what the gluteus maximus is designed to do. Obviously, to run you need to pull your leg back (extend your hip) very quickly. The faster you run, the more your gluteus maximus gets worked.

I'm a big proponent of training explosively because it recruits the most muscle fibers and it's the foundation of my book, Huge in a Hurry.

Now think about what a sprinter does hundreds or thousands of times each day. She performs hip extension, explosively. The often forgotten element in the quest for glutes of steel is explosive tempos.

This is why marathon runners aren't known for having a great ass. Even with hundreds of thousands of hip extensions they still don't build a great ass because they're not training it with enough intensity to tap into all of the muscle fibers.

Remember, the only way to recruit all of your muscle fibers is to train with maximum acceleration. You can't run at top speed for more than 10 seconds.

What to Do

There are three exercises you should start doing today to get the ass you've always wanted. Each exercise allows you to contract the gluteus maximus with smokin' acceleration and maximum force.

Here's an awesome ass-building workout to do three times per week at the beginning of your training sessions.

1. Sprints

How to do it: Run at top speed for 10 seconds; not a second longer.

Exercise Prescription: Perform 8 sprints with one minute of rest between each run.

2. Swings

How to do it: Stand with a wider-than-shoulder-width stance, with your feet angled out slightly. Hold a dumbbell, kettlebell, or medicine ball between your legs with both hands.

Push your hips back and squat down while holding your chest high. Squat down until whatever you're holding is below knee level. Explosively pull your hips forward (extend your hip joint) as you swing the dumbbell, kettlebell, or medicine up to chest height while keeping your arms straight.

Keep the swinging/squatting action going for 10 seconds. It's imperative that you maximally squeeze your glutes (lock out your hips) with each swing.

Exercise Prescription: Perform five sets of swings for 10 seconds. Rest 45 seconds between each set.

3. Glute Bridge

How to do it: Lie on your back with your knees bent to 90 degrees. Pull your left knee up to your chest and hold under the knee with both hands. Lift the toes of your right foot off the floor so your heel is the only part that's touching.

Bridge your hips up, while pushing through your right heel, and lock out the right hip as hard as possible for one full second. Squeeze it hard! Lower and repeat.

Exercise Prescription: Perform three sets of 10 reps with each leg. Don't rest between your right and left glute bridges. After you finish both sides rest for 30 seconds and repeat it twice more.

Final Words

Now you have all the tools you need to carve out glutes of granite. Not only will you look sexier, but you'll also become a better athlete since strong, powerful glutes will help you excel in every athletic event. So, no matter your goal, this simple workout is what you need.

Just sprint, swing, and bridge that ass!

About the Author

For more of Chad Waterbury's information, pick up his e-book The 10/10 Transformation here. His book Muscle Revolution can be purchased here.