Ask the Experts: Bobby McGee - Clarifying Flexibility Terminology

Those who have had a chance to see Bobby McGee speak, read his books or viewed his instructional DVD know that Bobby suggests keeping certain muscles "tight and small," such as the abdominals and hamstrings, as well as the "external rotators." This sometimes causes confusion, especially in light of the common athletic practice of stretching and increasing flexibility.

Here, Bobby follows up on two points that he made at Endurance Corner's Boulder Camp:

• Athletes shouldn't stretch the posterior (back) side of their kinetic chain, with the exception of the soleus.
• Athletes should avoid exercises (yoga poses, breaststroke kicking) that would result in increasing the external rotation of their legs and loosen the ligaments around loading (elastic) joints. Doing so causes power leaks and loss of elastic storage as well as instability.

From Bobby:

There is a difference between “tight” and taut muscles. A good analogy when it comes to core or pelvic platform stability is that of a basketball: a flatter (less pumped) basket ball is “more flexible,” but has much poorer rebound than one which is pumped to the correct pressure.

Hamstrings, calves (specifically the soleus), arches and a pelvis that are too loose -- those that give too much when the foot strikes the ground -- dissipate energy, while those that are more taut store and then return energy more effectively.

Those levers aren't the body's only levers that function this way and the process isn't simply linear -- it also happens rotationally. The external rotators are primarily the glute medius and minimus muscles and their normal function is to rotate the legs open –- from feet straight forward to pointing outwards (12 o'clock position to the 10 and 2 position). If those muscles are too loose, they'll lead to a similar loss of energy and destabilize the hip.

Perhaps the hardest of all the movements in running to understand is that of balance. The body is not only “holding” everything in place so that the legs can get the most force and unloading, but it is also dynamically moving and timing the placement of the weight in such a way that these forces are optimally used to propel us forward and not off to the opposite side of the support leg -- a nifty, well coordinated trick indeed, 180 plus times per minute!