Bodyweight exercises are all the rage, and for a good reason. Push-ups, pull-ups and bodyweight squats are elemental -- a lot of other exercises are actually variations of these basics. These three bodyweight exercises are so effective and comprehensive that you can build an entire program around them.

Although each move targets a major muscle area, these compound moves bring all the supporting muscles into play. Don't feel bad if you can't perform some of these simple strength-intensive exercises. There are specialized equipment and targeted exercises to help you develop the strength, form and power to go old school like a pro.

Push-Ups

The push-up is probably one of the most familiar exercises on earth. It works the pectoralis major, a powerful muscle that fans out over your upper rib cage. If performing a full-body push-up is initially too challenging, try a knees-down variation.

Trouble keeping your back straight while executing a push-up? Working with planks can help you build the core strength required.

Smith Machine

The Smith Machine is a great tool for developing chest strength, especially if you're training alone or just beginning. You can squeeze out those extra reps without worrying about dropping the bar on your neck because the machine has a safety lock that is easily engaged with a turn of the wrist. Set up the bench directly under the bar and position your hands slightly wider than shoulder width. Your ring finger should line up with the band on the bar.

Pull-Ups

The pull-up targets the back muscles, along with shoulders and arms. There are even more variations possible on this compound powerhouse, with overhand and underhand grips and various hand placements.

The most simple variation is executed on a straight bar, with a wide, overhand grip. Many people have difficulty with this exercise initially, as few people have the back and shoulder strength required to lift their entire body weight.

Luckily, there are chin/dip stations that can help you perform this exercise in perfect form while you work your way up to an unassisted pull-up.

Pull-Downs

Cable pull-downs are another great exercise for building strength, and because they are performed from a seated position, they can help you focus and develop explosive power. Sitting upright with an expanded chest, pull the bar down quickly to your chin, exhaling and squeezing your back muscles together. Release it with a slow, controlled motion.

For more, check out our guide on mastering the pull-up.

Bodyweight Squats

The squat is the ultimate bodyweight exercise because it engages so many muscles and requires excellent coordination, flexibility, power and strength. It works the whole leg, back and core, and when you introduce a weighted bar, even the shoulders and arms get involved.

Your individual build, whether you are short or long-limbed, the flexibility of your spine, and the strength of your legs all impact how you can squat. A long-limbed individual will never appear to squat as deeply as a short-limbed individual. Always be safe! Following the American College of Sports Medicine's recommendations will save you from unnecessarily stressing and possibly injuring your knees or back.

Tight hips, rigid ankles, stiff back? The resting squat might help you ease those tight places while building strength.You'll probably need to elevate your heels, though, or you might tip over. Ease into this squat and work your way up to ten minutes a day. Slowly decrease the support under your heels until you develop the strength and balance to maintain the pose. Work on driving your heels downward to strengthen and stretch your ankles.

Leg Presses

The more ways you can approach the squat, for example with different foot positions and angles, you will better be able to build the flexibility and compound strength required for this seemingly simple movement. The biomechanics of this motion are actually quite complex, and even one problem area (stiff hips, tight back) can cause difficulty. Working with an angled leg press can help you develop the strength needed to squat safely.

Keep the weights low enough that you can keep the proper form. Keep the knees in line with the feet, just as you would on an unassisted squat. Begin with your legs and torso at a 90 degree angle and do not lock your legs as you straighten them.

Don't Give Up

Three simple moves, and yet mastering them can require hours of dedicated training. The good news is the rewards make it worthwhile: Greater strength, endurance, muscle tone, improved posture, and the increased confidence that comes with it.