Lunge
MayoClinic.com recommends this body-resistance exercise for toning the quadriceps and hamstring muscles in the leg. Begin by standing comfortably with your feet together and step your right foot forward three to five feet. Lean forward and bend your right knee until it reaches a 90-degree angle, with your lower left leg parallel to the ground. Hold the position for three to five seconds before returning to a standing position and repeating until you have performed at least 10 lunges for each leg.
Heel Raises
Heel raises are a simple exercise for targeting the calves and lower muscle groups, and can be performed practically anywhere. Maintain your balance by standing near a desk, doorway or other sturdy object and placing your hands upon it. Slowly begin raising your heels so that your weight is shifted to the tips of your toes. Elevate your heels as high as you can before slowly lowering them back to the ground and repeating 10 to 30 times.
Dumbbell Front Squat
According to the American Council on Exercise, this free-weight exercise primarily targets the quadriceps, erector spinae and gluteus muscles along with a variety of secondary muscles, including the abs, hamstrings and adductors. Begin this exercise by placing your feet shoulder-width apart, with your toes turned slightly outward. Take a dumbbell in each hand and let your arms hang along your sides with your palms facing inwards. Contract your abdominal muscles while curling the dumbbells upward to your shoulders and bending your knees, allowing your hips to lower until your thighs are parallel to the floor. Bend forward to maintain your balance as you squat, touching your elbows briefly against your thigh before returning to a standing position. Repeat 10 to 12 times as needed.
Safety Concerns
Talk to your doctor before beginning a strength-training regimen if you have suffered previous injuries in your legs, back or abdominal area. Although some leg muscles are less prone to injury than other muscles in the body, improper technique can lead to strains, sprains and other injuries. If you are currently suffering from back problems, reduce the strain on your spine by tightening your abdominal muscles before beginning a lunge or squat exercise.