Active Isolated Stretching is a modern technique for lengthening and strengthening muscle tissue based on sound scientific research into how muscles work.
Your muscles have two basic actions: they can either contract or relax. AIS makes the simple observation that only relaxed muscle tissue can stretch to it’s maximum length.
The Law of Reciprocal Inhibition states: “When you contract one muscle, it’s opposite (antagonistic) muscle will then relax into a stretch.”
This stretch should be held no longer than 2.0 seconds to avoid triggering the protective “myotatic stretch reflex.”
The method of Active Isolated Stretching is rather simple:
- Identify the Specific Muscles to be stretched
- Isolate the Muscle using precise alignment
- Exhaling, engage the muscle opposite of the isolated muscle. The isolated muscle will then relax into the stretch.
- Once you reach the end range of your stretch, hold the stretch for no longer than 2 seconds.
- Release the stretch back to a “neutral” non-stretching position.
- Repeat the stretch 8-10 times, gradually increasing the stretch each time.
Why 2 seconds?
One of the most profound realizations of AIS is the practice of the 2 second stretch. Muscles have a protective mechanism called the stretch (mytatic) reflex which prevents the body from being damaged through radical movements. This stretch reflex is normally activated in the muscle at about 3 seconds. Therefore, using the 2 second stretch avoids the protective reflex, allowing for maximum elongation of the muscle and deep myofascial tissue. Repeating the stretch up to 10 times will allow the muscle length to gradually increase without ever signaling the stretch reflex which can actually cause muscles to tighten in order to protect the body from injury. The 2 second stretch allows muscles to receive maximum nourishment of blood and oxygen without engaging the protective stretch reflex
Pain free
People are rarely if ever sore after AI Stretching. The AI Stretch reduces lactic acid by pumping fresh blood and oxygen into the muscle tissue. This is a departure from standard stretching techniques which can cause micro-tearing, reduction of blood flow, and the build up of scar tissue as the muscle heals. This is one of the main reasons that so many of us assume that stretching is painful or even dangerous. AIS avoids painful tears. In fact, pain is in direct opposition to the AIS principle of bypassing the protective stretch reflex. When the body experiences pain, we tighten up as to avoid injury. AIS is typically a very pleasant experience, similar to having the muscles massaged from the inside out.
Building Strength
By the way, AIS builds specific strength in the antagonist muscles due to isolated contractions.
AIS for fitness
National Public Radio did a story in 2006 on how AI Stretching may act as a fitness program in itself. Listen here
Why Isolate Muscles?
Conventional stretching techniques will stretch several muscle groups at once. While there are certainly advantages to group muscle stretching, this can lead to “blind-spots” wherein the individual will “recruit” flexibility from one muscle group to compensate for tightness of another. Muscle Isolation can not only give us greater awareness of our bodies, it especially useful in addressing injuries and other therapeutic needs.
How to Isolate?
Our video stretching sequences show you how to use precise skeletal positioning to isolate individual muscles for effective stretching.




