Quadriceps thigh muscles

Squats with weight on shoulders

Get under the weight bar resting on a stand with your shoulders lowered. Grasp the bar - it should touch your shoulders. Push your chest forward. Place legs a shoulder-width apart (or even wider for better balance). Your feet must completely adhere the floor with the weight based on your heels.

Inhale, take the bar off of the stand start exhaling while bending your knees slowly. Keep your back upright. Your feet and hips should be in the same line - you have to bend your knees in a straight line above your feet. Reach the lowest position until you feel your muscles stretched to the maximum.

Slowly return to the standing position using your heels to push yourself up.

* This exercise can be also done with the Smith Machine or dumbbells. 

Squats with weight on the upper chest

Grasp the bar with your arms crossed and put it on your upper chest.

Do squats exactly the same way as in the exercise above (Squats with weight on shoulders).

Squats with weight behind back

Grasp the weight bar and hold it behind your back with your arms straight under your buttocks. Use lighter weight in this exercise.

Stand upright and push your chest forward. Place legs a shoulder-width apart with your arms alongside your torso. Hold the bar behind your back. Start bending your knees slowly until they are at a 90-degree angle. Push your knees slightly forward. Your feet must completely adhere the floor.

Slowly return to the standing position using your heels to push yourself up.  

* This exercise can be also done with the Smith Machine. 

Lean-back squats

Do the squat while leaning your torso firmly back - at the same time you can do a toe raise and push your knees forward. This way you can stretch your thigh muscles more.

This exercise can be done with weight - hold on to something stable with one hand and keep the other with some weight on your chest. Use light weight in this exercise (e.g. a light dumbbell). 

Straightening legs while sitting

Sit down on the machine and push your back against the support while grabbing ledges of the machine with your hands. Put your feet under the rod (at the height of your ankles). Inhale before you start. Straighten your legs completely while exhaling. Keep your legs straight for a couple of seconds. Return to the starting position as slowly as you can.

Pushing weight forward with legs

Sit down on the machine and push your back against the support. You can train different parts of quadriceps muscles depending on the angle. Place your feet a shoulder-width apart on the feet support, keep your knees straight, but not completely. When bending your knees don't bend them too much (it is bad for your joints).

Inhale and start bending your knees slowly until they are at a 90-degree angle. Then, while exhaling, start pushing the weight slowly forward until you go back to the starting position.

Remember to choose a load suitable for your fitness level.