Hamstrings and Quads should be the "yin yang" of the body working together in harmony. The quads a little stronger than their posterior friend then hamstring. Hammies, however, give many a runner trouble, particularly on long runs. Hamstrings aren't supposed to be as strong as quads, but many times runners, especially distance runners, have overy dominant quads. This is often the case in runners who heel strike. They're constantly loading the quad ready to pull their bodies forward due to the wider stride. This constant activation strengthens the quad but weakens the hamstrings. Sometimes the quad can get so out of balance that it can pull on the hamstrings causing them to become tight setting the runner up for injury. Or the hamstrings become weak, so when they are needed on a run, the may pull or cramp.
The best recommendation I have is to reign in the stride so the foot lands more under your center of mass. This decreases the quad activation, keeping everything in better alignment and letting the body work more like a shock absorber. You can also work to strengthen the hamstrings. The exercise below is a great one to do just that. This take on a simple hamstring leg lift uses a med ball as the base for the working leg. The med ball adds a balance element causing you to focus more on using the hamstring to lift the torso into a bridge. It's also a great core exercise.
To do the exercise, lie on a mat. Place your left foot on top of a medicine ball. Raise your right leg while keeping the left foot on the ball. Use the left leg to raise your body off the mat until your body is a straight line from your left knee to your shoulder, then lower your body until it almost touches the floor. That's one rep. Do 8-10 or 12-15 reps. Repeat the process with the right foot on the step and the left leg in the air.
Mother Nature likes balance. Science calls it homeostasis (stability within the body). This Yin and Yang appears all throughout the various body systems, especially within the muscular system.
Muscles can act as an agonist (the contracting or working muscle) or as an antagonist (the lengthening/stretching muscle) . Usually agonist and antagonist muscles are located direclty opposite one another. For example when doing a dumbbell bicep curl, you're using your biceps as the agonist and the muscle group directly opposite the biceps (the triceps) are the antagonist muscle group. If the triceps are the "working" muscle group (as in a tricep kickback), then the biceps become the antagonist. In many cases agonist and antagonist muscles are located anterior (front) and posterior (back) on the body (i.e, biceps/triceps, quads/hamstrings, pec/traps, but you can also have medial (close to the midline of the body) and lateral (along the outter sides of the body) agonist and antagonist muscles such as the adductor and abductor muscles in the legs. And you can have agonist and antagonist that are superior (above) and inferior (below) such as delts and lats.
The key "Yin and Yang" muscle groups for runners are the quads and the hamstrings. There are four quadricep muscles (vastus lateralis, rectus femoris, vastus intermedius, and vastus medialis). The quads work as agonist when they contract and flex the hip and further down work with the patellar tendon to extend the knee and pull the lower leg forward. Opposite the four quad muscles are the hamstring muscles (biceps femoris, semimembranosus, and semitendinosus). As the quads work as the agonist and contract, the hamstrings stretch or lengthen working as the yang to the quads' yin.
However, what goes up has to come down, or better yet, what contracts has to relax. So, when the quads contract and flex the hip and extend the knee, the hamstrings switch gears from being the antagonist to becoming the agonist (the working muscle) in order to extend the hip and flex the knee moving both the upper and lower leg backward. When this happens, the quads switch to antagonist mode as they begin to lengthen and relax.
Now this Yin-Yang doesn't always mean a 50/50 relationship. Your quads are a little bigger than your hamstrings and they just get used more throughout the day, so typically your quads are a little stronger than your hamstrings. The normal strength imbalance between the quads and hamstrings is a 3:2 ratio. Women tend to have less of a difference than men.
Runners can have issues with their quads, but more than likely they'll have issues with their hamstrings, especially distance runners. If you haven't had issues, I'm sure you know of a runner who has suffered from a hamstring strain, pull, tendinitis or even worse, a tear. The cause of the hamstring injuries can be from having weak hamstrings, but more than naught, the cause is quad dominance.
When runners log lots of miles they repeatedly load their quads, making them strong. Longer runs can lead to overloading the quads making the quads too strong. This can create an imbalance between the quads and the hamstrings. When this occurs, several things can happen. A worst case scenario would be a hamstring tear. This happens when the hamstrings are too weak to handle the pull of the quads, so they give way or tear. Quad dominance can also wreak havoc on the knees. A healthy counter balance of the hamstrings helps to keep the knees stable. When the quads are too dominant they can pull and tug on the knee joint, muscles, and/or ligaments causing damage. A frustrating result of quad dominance can simply be decreased power causing you to run slower. This happens when the hamstrings kick in sooner than normal to help decrease the overpowering of the quads.
Runners should try very hard to take care of their hamstrings by building up the muscular strength and endurance. Once you get in a quad dominant situation, it's kind of hard to reverse. Also, hamstring injuries usually take a while to heal, so you may be off running for extended periods of time and frustrated.
So, what's a runner to do? Well the first thing that comes to mind is hamstring exercises, right? Right! But hold on, are some exercises better than others? Yep! The typcial hamstring leg lifts, hamstring leg curls, or hamstring roll-ins on a stability ball are all good, but research has shown that eccentric-loading hamstring exercises are even more beneficial, so be sure to throw in some exercises such as eccentric leg slides and hamstring curls. Check out the video below for examples of some great hamstring exercises (including some eccentric exercises) to add to your weekly lower-body or full-body workout routine.
Seems like lately, many of my running buddies, both local and cyber, are being plagued by hamstring injuries. The problem with hamstring injuries, is that they hurt like hell and take a while to heal. Neither does a runner want to deal with. Telling a running not to run for a few weeks, is like taking their first born.
So why are runners (especially long distance runners) plagued by hamstring injuries so often? Well, there can be many causes—going out too fast and too strong without properly warming up, not properly fueling the body, dehydration, lack of strength in the posterior chain (back, glutes, hamstrings), and being quad dominant. And then there is always the odd injury for which there is no apparent reason for the cause.
From my reading, schooling, and talking with other runners, being quad dominant and having a weak posterior chain are probably the two biggest causes of hamstring injuries. I've mentioned it in previous posts how so often runners do not include resistance training into their weekly routine. Runners often shy away from the gym because they feel they're getting enough exercise on the run. They also don't want to bulk up.
Runners need to change their perception of the gym. They also need to realize that many resistance exercises can be done using body weight or light weights at home. And no, doing resistance training will not turn you into a bulky "Arnold" and no you won't gain an Austrian accent in the process.
A December 2008 Running Times article does a great job of explaining the issue of quad dominance. In a nutshell, quad dominance happens when the "quad muscles overpower the action of the hamstrings in the movement of the leg during a running stride."
Long distance runners log a lot of miles. That constant repetitive action puts an overload on the quads causing them to become more dominant than their antagonist—the hamstrings. When your hamstrings become significantly weaker than your quads, then Running Times says one of two things may happen:
1) Your hamstrings will tear as a result of not being able to take the load developed by the contracting quadriceps and momentum from hip extension 2) You will run slower as a result of diminished power from the hip flexors and knee extensors as the hamstrings have to contract earlier to be able to break the ensuing movement.
Hamstring injuries are slow to heal and often, once you get them, they'll reoccur over and over. The recurrence, however, is usually due to the runner not addressing the real cause of the problem......weak hamstrings. That's where resistance training can play a huge role in overcoming or preventing this problem.
First of all, for everyone (not just runners) strengthening the posterior chain (the muscle groups found on the back side of the body) is most beneficial. Having a strong posterior chain can help prevent a whole host of injuries especially later down the road as we age. The posterior chain mainly consists of the erector spinae muscles (the lower back muscles), the glutes (butt muscles), and the hamstrings (upper backside of the leg).
Exercises that target the hamstrings include: Dumbbell Squats
