PAILS and RAILS are the next evolution of “stretching.”
There have been multiple phases of mobility and stretching since coaches realized their athletes needed more flexibility. The first stage was the addition of simple static stretches into workout programs. This is the classic style of stretching such as leaning over and trying to touch your toes for about 20 seconds.
The next development was called PNF (Proprioceptive Neuromuscular Facilitation). This style includes a phase of slight resistance to the stretch and then sinking deeper into the range of motion. Imagine stretching your calf by putting the ball of your foot on a curb while leaving your heel on the ground. After stretching for a bit you lightly press your foot into the curb and then relax. When you relax you are able to sink a little deeper into the stretch. With this technique you usually only press with about 5-20% effort and stretch for about :20 between presses.
PAILs and RAILs (Progressive/Regressive Angular Isometric Loading) are the next iteration beyond PNF and are our favorite way to include mobility work within your training sessions. Not only do PAILs and RAILs increase range of motion, they also increase strength in your ranges of motion and raise your heart rate.
PAILS and RAILS begin with a full 2:00 passive stretch. Let’s return to the calf stretch example. You relax into the initial stretch for 2:00 allowing the calf muscle to gradually release more and more tension. After this you begin to resist the stretch similar to PNF. You press the ball of your foot into the curb like pressing a gas pedal. Unlike PNF, however, you only begin at 20%. Then you build all the way to pressing with 100% max effort into the curb for :20 seconds. At the end of the :20 you don’t simply relax, instead you actively pull your toe towards your shin and your shin towards your toe. Do this for :10. By increasing the effort in both directions you gain more range of motion than previous methods and train your muscle at those end ranges to be strong.
Try this technique next time you decide to throw in some stretching. Just be ready for it to feel much more like working out than normal stretching.