Marathon training: Have you forgotten about running economy?

This blog was originally posted on the Inspiring Fitness blog site

The Importance of Resistance Training

If you are running the London Marathon, especially if you are hoping to cover the 42km in the fastest time possible, you’re probably aware that there are three components of running fitness: VO2max, lactate/anaerobic threshold and running economy.
You have been pounding the street and/or treadmill in preparation. You’ve definitely been doing long, slow distance runs, in an attempt to get your legs used to jogging for hours on end. These runs will serve to increase your VO2max (the maximum amount of oxygen that can be transported to and used by the muscle).
You may even have done some interval training or ‘lactate threshold’ conditioning to help allow yourself to run at a higher pace and heart rate throughout the race. These intervals will also serve to increase your maximal capacity.
But what about the third component?

Running Economy
Running economy is how efficient you are at running, that is, the amount of energy required to run a certain pace.
How Do I Improve My Running Economy?
Basically, if every step you take requires less energy or you can travel a greater distance by taking fewer steps, then you will improve your running economy.
But my technique is really good! How else can I conserve energy?
The simply answer is by decreasing the effort required to take each step whilst running, that is decreasing the amount of energy needed to push off the ground.

Decreasing The Effort Required To Propel Your Body
Each step you take, muscles contract to push you forward. Like any muscle contraction, these contractions will be a percentage of your maximal voluntary contraction (MVC). Your MVC is the maximum amount of force a muscle or group of muscles can generate.
100% of your MVC will require 100% of your motor units. A motor unit is a nerve and all the muscle fibers it innervates. Each muscle unit requires a certain amount of energy to contract. If you reduce the percentage of your MVC required to perform a task, you will reduce the amount of energy required to perform that task.

How do I reduce the percentage of my MVC required to run?
You could reduce the amount of force requires to move your body; that would involve reducing your weight (that is why elite marathon runners are so small) but, seems that you are already in training for the marathon, you are probably unlikely to be able to reduce your weight greatly, without it compromising your performance.
What you should do is increase your MVC so that, though the force required to propel your body forward is still the same, the percentage of your MVC is reduced, decreasing the energy required.
How do you increase you’re the amount of force your muscles can generate? Strength training!
Can resistance training help decrease the amount of energy required to complete a running event in any other way?
Yes, it can. I’m glad you asked!
Some of the other ways in which resistance training can decrease energy expenditure, leading to better running economy are:

• Strength training has also been shown to lead to ‘stiffer’ muscles, in this case in the calf. Each time the foot strikes the ground, the calf muscles have to counteract downward momentum through an eccentric/lengthening contraction. Once the force has been absorbed, the muscles propel the leg forward through a concentric/shortening contraction. Stiffer muscles mean that this lengthening contraction is reduced, ideally to no change in muscle length at all. Instead the force is transferred to the Achilles tendon. Tendons are very elastic, that is they absorb force by elongating and return it in the opposite direction when they return to their original length. The return of energy in the tendon conserves the kinetic energy and transfers it in the opposite direction to plantar flex the foot and propels you along your run, meaning you do not need to produce energy to push off the ground with the calf muscles.
• Explosive resistance training and plyometrics (unweighted jumps and bound) have been shown to increase the amount of force that can be imparted in the short amount of time the foot is in contact with the ground during running. This can lead to increases in stride length. Also, proper periodised resistance training has been shown, in a 2008, Journal of Strength and Conditioning Research study, to prevent the loss of stride length at the end of intense endurance running events. Less strides taken during an event means less energy expenditure. to prevent the loss of stride length at the end of intense endurance running events. Less strides taken during an event means less energy expenditure.

  Is there any other resistance training that I can do to improve my running performance?
  Perhaps! A 2009 study concluded that for those with weak core stability, conducting specific training for this area may improve running performance.
  

  Conclusion and Practical Experience
  As you can see, though many recreational runners who attempt marathon know that different modalities of cardiovascular training are required to complete the course in the fastest time possible, resistance training is also important in running performance.
  I recently had a client who had previously completed a marathon in a fairly good time but wanted to improve her running speed. Through a properly periodised resistance programme, we managed to improve her 10km time by a whopping 24%! This proves that resistance training can be a powerful tool to helping you run the race of your life!
  Consult your personal trainer or fitness coach on what resistance exercises to perform to increase your running performance.