
PAILs and RAILs from my experience has been the extremely effective at improving my mobility.
And it makes sense. Quite honestly it changed the way I do my mobility work.
I first discovered Kinstretch and functional range conditioning when I was at a local
crossfit gym…
…I was on one side of the gym doing romwod at the time and I was just camped out in a stretch.
This other guy was working his a** off doing mobility work and I was really intrigued.
That was in 2015.
Since then I went on a quest to learn as much as possible about this style of mobility training.
In this blog we will break down:
- What are PAILs and RAILs (Kinstretch)
- Do PAILs and RAILs actually work (heck yes they do)
- How to do PAILs and RAILs (some examples)
To fast track your mobility join our FREE 3 day mobility workshop.

What is PAILs & RAILs
The most effective way to improve your mobility is the short answer 🙃
By definition:
An isometric loading protocol/strategy created by Dr. Andreo Spina who created Functional Range Conditioning (FRC) and Functional Range Systems (FRS).
PAILs & RAILs stands for what?
The “IL” stands for isometric loading.
This is where we are contracting or putting force into a muscle/tissue.
However depending on if we are being:
progressive “PAIL”
or
regressive “RAIL”
will change where you are connecting your mind/muscle and energy.
PAILs stands for progressive angular isometric loading.
RAILs stand for regressive angular isometric loading.

Example of progressive angular isometric loading (PAILs)
In the photo above, I’m doing the classic couch stretch.
The king of all stretches. Now let me show you how to optimize this stretch.
There are of course a few ways you can go about this but I personally like to start with a
small amount of tissue work (self myofascial release). Not for the purpose of breaking up any muscle tissue.
Rather, to communicate to my body and muscles to relax or “reduce some stiffness” so
when we do begin to stretch that muscle has loosened up a bit.
- :60 second tissue work
- :60 second stretch (in this example the couch stretch)
- Then I would begin to apply the PAIL (progressive angular isometric loading)…
…like this:
- Begin to PUSH your leg against the box.
- We will do this 3-5 reps so on “rep one” push against the box at an effort of about 50% for 10-20 seconds.

After the PAIL you would apply the opposite…
REGRESSIVE angular isometric loading and you would then CONTRACT the opposing muscles to strengthen and activate those muscles at end range.
In the photo above I’m now recruiting and activating my hamstrings to pull myself deeper into the stretch.
This is done at max effort.
Connecting mind and muscle to activate and squeeze as hard as possible for 10 seconds.
Then back off, take a couple of breathes.
Then you would perform another “PAIL” and you would then increase the intensity of the push into the box.
Perhaps 70% this go around.
Each rep increasing intensity and eventually getting into pushing as hard as you can.
More details on this later where I lay out a step by step process.

Does Kinstretch (PAILs & RAILs) actually work?
I would like to talk about my story a bit more I mentioned above.
Where I was at a local crossfit gym probably in 2015.
I was in one corner of the gym following romwod and this other guy was doing functional range conditioning.
But at the time I had no clue what he was doing.
Romwod which is now pliability method has it’s own purpose and it’s’ great. Which is to get you into a calm and restorative state and improve mobility.
However after years of trying both romwod & gowod I can confidently say I don’t believe that JUST stretching is going to lead to better mobility.

As I mentioned before romwod (static stretching) or even gowod is not what I would call “training mobility”.
The guy across the room was TRAINING mobility.
His muscles were shaking, he told me sometimes he would even cramp (a sign of muscles that aren’t used to being called upon).
But it all made sense because he was strengthening his END range of motion.
And that’s what functional range conditioning does.
None of the earlier text books teach this though. They want to to hold a passive stretch for 2 minutes, maybe do some contract and relax business.
Then load the new range of motion with weight so your can adapt to this new position…
…but this style is different and much more effective.
Now I lead athletes through daily 15-20 minute virtual class mobility sessions with all the techniques I have learned over the years.
Check out how my mobility classes work:
Hope to see you in class 🙃
How to do PAILs & RAILs (step by step)
You can use this mobility method for anything:
- shoulders
- ankles
- hilps
- the list goes on
By the way imagine spending time working on mobility and actually seeing improvement.
Wouldn’t that be nice?
That’s what happened to me when I started applying this method to myself and to other athletes.
Here is how to do it on your own:
- Choose an area you want to work on (let’s say hips)
- Spend a few minutes taking some time to smash some tissues aka foam roll.
- Then get into your position of restriction let’s say the 90/90 hip stretch (spend 2 minutes breathing and settle into your stretch)
- Perform 5 reps of PAILs and RAILs
During rep one “progressively” increase intensity. Maybe 50% and for :10-20 seconds begin to push your foot/hip into the floor and ramping up (like your turning a dial) to 60%.
Immediately after go into your RAIL and recruit the opposing musculature and this is max effort.
Put your mind where those muscles are and try to strengthen the end range.
- After completing 5 reps (each rep increasing intensity) then hold your “new” range of motion you established for a final stretch of :60 seconds
Pretty intense right?
It was an entirely new concept that I had to learn after years of yoga, studying Kelly Star, taking classes from romwod (pliability), gowod and all the other great industry leaders.
But I’m thankful for functional range conditioning has taught me and how I’m able to help athletes get stronger and improve mobility.
Conclusion
PAILs & RAILs is in my opinion the greatest form of mobility training out there.
It teaches your brain and your muscles to be STRONG and strengthen your end range.
I laid out above a few examples of how to apply this to your hips but as mentioned you can do this for shoulders, hips, ankles, wrist, essentially any joint your range you want to improve.

Comment below with your biggest take away!
Any additional questions drop them in the comments below.
- -Coach Kevin 🤙🏻