So everyone understands that getting stronger by lifting weights will actually make you a faster runner and will not get big and bulky, please read this blog post here and this article here.  Also let's quickly revise the dynamics of running.  There are basically three parts to running: the stance phase (which is the amount of time you spend on the ground every time your foot touches the ground), the stride length and the stride rate (or frequency).  To run faster, you have to either a) decrease the stance phase, b) increase the stride length or c) increase the stride frequency.  As I have mentioned here, this applies to every distance from a 100m sprint to a ultramarathon.  The second group of muscles we are going to talk about in regards to their importance to running and why they need to be as strong as possible are the hamstrings and in this case when they extend the hip.

The portion of the hamstrings that extend the hips are a vital part of propelling the body forward during locomotion.  This extension of the hips is vital to almost every running based sport and it is why most good strength and conditioning coaches and personal trainers use exercises that involve triple extension (extension of hip, knee and ankle) like Olympic lifts.  The hip extensors are predominately made of slow twitch muscle fibers.  This again influences the amount of repetitions you should use to train them with. 

The hamstrings as a hip extensor play a crucial role in running fast

The main aspect of running that improving strength in the hamstrings as hip extensors will benefit is your stride length.  It does this in two ways.  The first is by increasing the force the hip and the leg applies to the ground each stride.  This increase in force gives a larger ground reaction force to the body and results in greater speed and greater distance travelled per stride.  As you can no doubt reason, improvements in hip extensor strength are vital for acceleration and speed.  This aspect of running is not only important for sprinters and other team sports athletes but also long distance runners or marathoners too as they change pace to distance themselves from a competitor or have to outsprint another runner at the finish line.

The second way it increases stride length is that it decreases inhibitory measures the body uses to protect the hamstring during running.  If the hip extensor portion of the hamstrings is weak, the brain will send inhibitory signals to the legs preventing them from entering a range that might cause a hamstring pull for their current level of strength.  When you become stronger in the hamstrings, the runner can handle greater loads through the hip extensors.  This means the brain does not need to send the same inhibitory messages at the same stride length or speed (because now the runner can handle the increased eccentric load.  This means an increase in stride length (and therefore speed) is developed.

The best ways of strengthening the hip extensor part of the hamstrings, besides the aforementioned Olympic lifts, involves variations of deadlifts, back (hyper)extensions and reverse hyperextensions.  Just like the knee flexor portion of the hamstrings, both open and closed chain kinetic exercises will benefit runners.  Here are examples of two:

The Straddle Reverse Hyper is a gymnastic variation that is great for strengthing the hip extensors and improving lateral gluteal function.

The Romanian Deadlift is excellent for bringing up hip extensor strength 

Strengthening the hip extensors will also significantly aid in reduction of hip related injuries and adductor/hamstring pulls.  It does this by increasing hip stability during running.  Another way it aids in reducing injury is that by making sure your hamstring as strong enough, the hips do not need as much contribution from other muscles that are not prime movers during running.  For instance, if the hamstrings as hip extensors are weak, a really common biomechanical issue that develops is that the pelvis has to rely on the posterior portion of the adductors to fully extend the hip.  This if unattended to for long enough can leads to adductor or groin strains and chronic overuse conditions like osteopubis.

Training the hip extensors (just like the knee flexors) will help you run faster and stay out of the physio clinic if you are doing a lot of running training.  Keep an eye out for Part 3 in this series where I will talk about how the quadriceps role in running super quick. Plus if you ever thought about running a marathon (or even half marathon), make sure you check out my Run A Marathon In 8 Weeks program by clicking here.