If you’ve trained with us onsite at MTN Lab you’ve no doubt either experienced or witnessed some very simple looking exercises being done with looks of intense focus and maybe some yelling. Welcome to FRC, which stands for Functional Range Conditioning, a training system that achieves a variety of goals through a focus on joint work. The end goal of this work is increased mobility, joint strength and body control. There are a number of different categories of exercises within FRC, and one that many of you have experienced are what we call PAILs and RAILs. These are acronyms for: Progressive Angular Isometric Loading and Regressive Angular Isometric Loading.

To start, let's define what isometric loading means.  An isometric contraction is a static contraction that allows you to really focus on the targeted tissue and gradually build up the tension you are creating.  This also means you will be able to recruit and fire more motor units, i.e. more muscle.  If you’ve ever felt like a muscle hasn’t been working as well as it should, a lot of times you’ll hear people say it’s not firing, it’s turned off, etc., Isometrics are a very effective way to “turn those muscles back on”. In reality what you’re actually doing is strengthening that neural pathway so that it becomes more accessible. When it comes to the progressive and regressive angles we are just referring to the tissues we are working and their relationship with a joint. The progressive angle is always going to be the tissue that is being stretched and regressive is the shortened tissue on the opposite side of the joint.

What we are working on is having you stretch to your end range (where you are weakest) and hold that stretch for 90 sec to 2 min so that your brain actually registers the stretch. (The research shows that any stretch less than this has very short-term effects). After this stretch, you are gradually ramping up the tension in the stretched tissue so that you don’t push too hard, too soon and so that you can develop more motor control of your ability to contract. This is the PAIL. We follow this up with your RAIL, which is contracting the shortened tissue or the muscles that would pull you deeper into the stretch.

True mobility is having control and strength through the entire range so that you are useful through that entire range of motion. By using PAILs and RAILs you will not only be gaining passive flexibility but will be building active ranges of motion and in the end, a body which is more resilient to whatever comes your way.

  • From Coach Nick Harbert