How do you build leaner, sexier and stronger quads, hamstrings and glutes? Not only are our lower extremities all interconnected, the legs are endurance muscles, and they are developed and maintained through the series of repetitions and hard work with strength training. Multiple studies show that regular strength training can improve athletic (especially running) economy—how efficiently the body uses oxygen—by as much as eight percent, translating into greater speed and more muscle endurance.
Many people are solely focused on upper body appearance and neglect the bottom half. Did you know that between the age of 30 to 70 years, muscle mass decreases on average about 30%; and the loss of strength is about the same? Much of that loss of mass and strength is in the lower body. According to Dr. Sal Arria, Executive Director, ISSA, more often than a disease, the debilitating effects attributed to aging can arise from disuse. Not being able to be mobile and agile from day to day, let alone later in life, can really limit people’s freedom and quality of living!
There really is no shortcut to health, fitness, and wellness. People have to do their homework and the hard work it takes to get results. The good news is that exercise and body movement can feel really great and satisfying, especially once you start seeing results and feel sexier, fit and healthier along the way! One of the key ingredients in building yourself a fabulous, strong pair of legs, in particular, are the following exercises, all designed to help people reach lower body optimization efficiently. On a day to day basis, the average person must utilize a great deal of balance and stability, forcing legs to work much harder than other body parts.
If you want to build fantastic leg endurance to improve your staying power in sports or want to be able to stay in power positions (such as different stances in martial arts) for long periods of time, you must develop strong muscular endurance. Benefits of endurance based leg exercises include better cardiovascular performance and oxygen delivered to the muscles being used. To maximize and strengthen your personal muscular endurance, try jump roping, cardio boxing, running, and cycling for at least an hour, for at least 4 days each week.
According to Dr. Sal Arria, Executive Director of ISSA, says that squats are one of the most beneficial exercises to not only prevent muscle from atrophying but to strengthen the entire lower body. Athletes call the squat, the King of Exercises. Unfortunately, they can complicate it so much that you would believe you have no place trying it. No doubt, there are little intricacies and tricks that competitive powerlifters implement when muscling hundreds of pounds up. However, you may never identify with these "tricks" when simply improving your functional health. Even after progressing from eccentric squats on the chair, to squats on a chair, you may be surprised how awkward this most common variation feels at first. 
Lower yourself to a point that your range of motion comfortably allows, never rounding your back, then without ever relaxing, return to an upright, standing position. From this point, as you see a need for greater resistance, you can rest a barbell behind your neck, adding weight to the bar as necessary.
The effects of exercise and disuse are well documented. The deterioration of the lower body is cyclical. Immobilization leads to obvious inactivity. People who cannot use their lower bodies infrequently find ways to exercise any portion of their body. Squatting may be more than a means to maintain a strong lower body, it may be a means to maintaining a healthy, active lifestyle.
To begin, stand and position yourself against a stability ball so the small of your back is centered on the ball. Lift one leg up slightly off the ground. You may have to experiment with proper leg placement, but you should be able to balance on one leg, with your foot slightly out in front of (not under) your knee. Place your hands on your hips.
Draw your belly button in toward your spine, keep your chest up, and slowly bend the knee of your supporting leg. As you lower your body, visualize rolling your glutes back under the ball toward the wall. Go down only as far as you comfortably can, but do not go past the point where your thighs are parallel to the floor. Exhaling, squeeze your glutes, pressing back against the ball, to return to starting position. Repeat. Do not let your knee travel out over your toes during this exercise.
Note: Do not let your pelvis come forward as you push up from the squat. Keep your hips at a 90-degree angle as you lower and return to starting position.
Walking and Barbell lunges are two of the best overall quad, hamstrings, and glute exercises. With a weight in each hand, you can execute the “walking” lunges. Placing one leg forward in the walking motion, where you lower yourself as low as possible, even attempting to touch your knee to the floor. You can also obtain the same results with the squat rack.
Leg press is one of the best leg builders and overall quad exercises. This allows you to use your hamstrings and glutes as well. Though it as not as targeted for your quads, this provides the potential for using very heavy weights. 
With the leg press machine sit with your back and head against the padded support. Place feet on the foot plate about hip-width apart, ensuring the heels are flat. The legs should form an angle of about 90 degrees and aligned with your feet. Push the weight up and lower the weight down to your glutes, repeat. Never lock your knees. With a few variations in foot positioning, you can work your hamstrings at the same time.
To start, stand and balance on one leg. Make sure your posture is neutral—your back should be neither overly arched nor rounded—and tighten your torso.
Slowly, bending at the hips, knee , nd ankle, reach down and touch the outside of your supporting leg’s foot with the opposite hand. Return to starting position, keeping your torso tight. Repeat. Do this exercise s-l-o-w-l-y to keep constant tension on your leg muscles and to keep your balance!
Note: If you are initially unable to reach all the way down to your toe without falling over, try reaching to mid-shin (or as far as you comfortably can) instead.
Like all muscles in your body, you can perform lower-body exercises up to three nonconsecutive days a week. If you're lifting heavy weights (enough that you can only complete six to eight repetitions), you'll need two or more days of rest before you perform the exercise again. For this reason, you might only work your lower body once or twice a week. If your goal is endurance and strength, stick with 1 to 3 sets of 12 to 16 repetitions and at least one day of rest before you perform the exercises again.
Resources: bodybuilding.com, livestrong.com, menshealth.com, shape.com, self.com, askmen.com
