Time to get off that leg curl machine and try some full-body workouts if you really want to work your hamstrings -- and of course you do, because they're part of the package that produces super-sexy legs. Dumbbell lunges use all the muscles in your lower body to move, toning and shaping your glutes and quads as well as working your hamstrings. Even though the top of your thighs feel the burn, your hamstrings are working quietly to assist your other leg muscles and buttocks to move.
Hamstring Function
Your hamstrings do more than just flex and extend your knee. They work with other muscles to stabilize your body when you stand still in various positions. They also assist your hip muscles to extend, abduct and rotate your hip joint. In a lunge, the hamstrings and quadriceps flex the front leg while these same muscles in the back leg extend the hip and leg. And so, doing lunges works your hamstrings in opposing patterns in each leg.
Eccentric Loading
The term "eccentric" here doesn't refer to your weird Aunt Batty, but to the way the muscle contracts. In the lunge, both legs contract, just in different ways. Eccentric loading simply means that your muscles are contracting as the joint angle increases and the muscle fibers lengthen under tension -- that's what your back leg does in a lunge. Meanwhile, your front leg is contracting the opposite way, by shortening; this is called "concentric" contraction. When your hamstrings work eccentrically in a lunge, it can help you develop better movement patterns and hamstring function. Adding dumbbells increases the load on your hamstrings.
Doing the Lunge
To do the dumbbell lunge, stand with your feet together and hold a 5- or 10-pound dumbbell in each hand by your sides. Step forward with your left foot and lunge straight down until your right knee almost touches the ground. Keep your torso upright and do not extend your left knee past your toes. Exhale and push yourself back to the starting position without hunching your back. Perform two to three sets of eight to 10 reps per leg.
Before Adding Weight
Before you use dumbbells for lunges, make sure that you can do them with no additional load, suggests physical therapist Gray Cook, author of "Athletic Body in Balance." If you lunge with poor balance and form, adding weight will not make it better -- it will increase your risk of injury.
