Your vastus intermedius -- like the Three Musketeers -- is all for one and one for all with the other muscles that make up your quadriceps. Your vastus intermedius, vastus lateralis, vastus medialis and rectus femoris buddy up as one unit to straighten your knee and lift it toward your head. As the largest muscle group, your quadriceps are responsible for quite a bit of your lower-body strength, so keep them fit and ready to go with some basic quadricep resistance exercises.
You can do squats with your bodyweight, dumbbells, kettlebells or barbells -- decide if you want to use resistance. If you do choose to use weight, pick a weight that you can squat eight to 10 times but doing 15 times would be too challenging. You can always adjust the weight later if you’re not sure. During the exercise, hold dumbbells by your sides, a barbell on your shoulders and a kettlebell with both hands in front of you.
If you’re not using weight, put your hands on your hips or hold them straight out in front of you. Stand with your feet shoulder-width apart. Puff your chest up as if you’re angry, and straighten up your back.
Sit your hips back as if you are about to sit on a chair behind you as you bend your knees. Keep your weight shifted to your heels, and while keeping your chest up, hinge forward slightly from your hips. Lower your body until your thighs are parallel to the floor.
Exhale and press through your heels to straighten back up to the starting position. As you begin to move up, focus your eyes on the spot where the wall and ceiling meet to tilt your head back and keep your chest up.
Sit back in a leg extension machine and adjust the pin in the weight plate to an appropriate weight for you. Aim to be able to do 10 to 12 reps.
Hook your ankles underneath the weight pad and grip onto the handles by your sides for stability. The machine should be adjusted so that your lower legs are able to hang freely and your back is flat against the back of the chair.
Exhale and straighten your knee, lifting the weight pad until your entire leg is parallel to the floor and you feel a contraction in your upper leg.
Don’t let the weight plates crash back down. Control the weight pad as you lower your leg to the starting position.
- Do two or three sets of each exercise two or three times a week but not on consecutive days. Start with one quadricep exercise and gradually add more as your legs become stronger. Start each workout with five to 10 minutes of easy walking, jogging or biking to get warmed up.
- If your quadricep muscles become a lot stronger than the other lower-body muscle groups, it can spell pain and injuries. To balance out your lower-body strength, do some hamstring exercises as well. Your hamstrings are the opposing muscle group to your quadriceps, and keeping them balanced improves function and keeps you from getting hurt.
Jilana Dennis is a health and fitness writer based out of San Antonio, Texas. Dennis is a nationally certified personal trainer with the American Council on Exercise and holds a B.S in exercise science from Illinois State University.