Elasticize Your Running Muscles

elastic band
By Dr. Aaron Case, DC, BSc (March 2010)
The elastic properties of your muscles and tendons are estimated to make up 40-50% of your running ability.  So, if you can maximize these built-in elastics bands, you can potentially run farther and faster.  This article outlines a few of the ways runners can use and maximize our natural elastic bands:
  1. Keeping your knees slightly bent
  2. Stretch LESS
  3. Pumping your arms LESS

Why are elastic properties useful?

The reason long distance runners want to enhance elastic recoil is that elastic energy can be stored in our muscles and tendons during the impact and movement that is inherent to running.  This elastic energy does not require any extra oxygen or fuel, saving our muscles for added endurance and speed.  When these elastic bands release at different times throughout our stride, this also allows brief moments of muscle recovery.  This enhanced muscle recovery allows for more aerobic and economical running, which is ideal for speed, endurance and injury prevention.

How does one efficiently use these built-in elastic bands?

1. Keep your knees slightly bent

Don’t straighten your leg completely at the front or back of your stride.  This keeps the quadriceps muscles in the front thigh slightly pre-stretched and ready to fire quickly, like an elastic band.  Another benefit to keeping your knee slightly bent on impact is that you are less likely to land on your heel in front of your centre of gravity.
knees
When your leg is at the back of your stride, pick your foot up more quickly to optimize elastic recoil after foot strike.  Otherwise, the pre-loaded elastic energy diminishes and you end up over-using your muscles to push off and catch up to the rest of your body.  You may even want to count your steps each minute (cadence) and gradually try to increase towards 180 steps per minute (similar to the cadence of elite runners virtually regardless of their speed).

How does this feel?

  • Run tall but sink into your legs slightly.  This technique will prevent you from straightening your legs at the front or back of your stride.
  • You could also imagine there are small, not-so friendly, dogs nipping at your heels and you need to keep just ahead of them.  Quick leg turnover is the key to escape from dogs and to run more efficiently.  If you are not sure what I mean, rub some liverwurst on your heels and run through a dog park.

2. Stretch LESS

If you are already quite flexible you may decrease your muscles/tendons ability to recoil during your run.  If your muscles/tendons are too flexible, they may respond to running like an overstretched elastic band.  In other words, to preload/recoil overstretched muscles you may need an artificially long stride for a given speed just to create a sufficient stretch in the muscle to trigger an automatic and optimal muscle contraction (via the muscle spindle that regulates muscle length and protection from overstretching).  However, over striding is not recommended because it can result in increased braking, impact and potential injury when running.

How does this feel?

  • If you are at the front of the Yoga class and/or others are impressed by your flexibility you may be ‘overstretched’ for optimal efficient (elastic) endurance running.  However, if you are at the back of the Yoga class (where I hide), you may need to stretch more often so that you are not such a stiff.
  • Current research indicates that too much flexibility may increase soft tissue injury (perhaps due to decreased stability) and too much stiffness may increase the risk of stress fractures. So, if your porridge is not too hot or too cold (i.e. you are in the middle of Yoga class), you are likely just right (or read too many books to your kids).

3. Pump your arms LESS

You may have been told to pump your arms to get your legs turning over faster.  For drills, sprinting, or the finish of a longer race, I agree.  However, for endurance running, any extra upper body movement in excess of the minimal effort necessary to balance and counteract leg movement is futile and costly.  By relaxing your upper body instead, the elastic connections through your core can work passively to perfectly time and co-ordinate whole body movement.  Arm pumping may work temporarily, but will only put you in oxygen and energy debt down the road.  Recent research suggests that runners push too hard up hills when arm pumping is often at its greatest.  A common technique suggested is to pump your arms to go faster up a hill.  However, one study showed an extra 78 seconds on average for runners to regain their initial speed after cresting a hill.  If upper body relaxation were maintained up the hill, this recovery would likely be reduced.

Also, I often find that excessive pumping of the arms or high shoulders are due to weak, inhibited or fatigued quadriceps.  I have been found excessively pumping my arms near the end of a marathon when my quads are “trashed”, until a helpful bystander tells me to relax my shoulders (at least I think it is near the end when bystanders keep telling me that I am “almost there”).

How does this feel/look?
Robert Cheruiyot

  • The best example I have ever seen of excellent upper body movement is the 21 year old 2010 Boston marathon winner, Robert Cheruiyot, who easily broke the course record of the 114 years of elite racing that has occurred on this course (picture above on the left, wearing purple).  His head, neck and back had almost no movement in rotation or lift.  Only  his shoulder joint hinged and his elbow stayed fixed near 90 degrees of flexion/bend.  He had the most relaxed upper body I have ever seen at that distance and ability.

Summary

If you want to run more efficiently and smoothly you must get your ‘elastics’ in the right position to release energy/force.  A combination of knees slightly bent at all times, picking your foot up quickly (high cadence), maintaining middle-of-the-road flexibility  and pumping your arms less with a relaxed upper body, may all help you run farther and faster.