Over the past two decades, many experts have advocated prolonged stretching up to 60 seconds. A prolonged stretch up to 60 seconds means that a person would move into a stretching position and keep it there for a longer period. For many years this was used as the gold standard for all individuals and athletes. However, after 30 years of research by Aaron Mattes, it was found that a stretch greater than 5 seconds actually decreases the blood flow within the tissue thus creating localized ischemia and lactic acid build up. This also increases irritation and change of injury of local muscular, tendonous, lymphatic as well as neural tissues, similar to the effects and consequences of trauma, overuse syndromes, and metabolic disease states. This phenomenon indicates that there has to be a better technique for proper stretching. And indeed it was found, now called Active Isolated Stretching.
Active Isolated Stretching (AIS) is a stretching method developed by Aaron L. Mattes. AIS utilizes precise movements to isolate a specific area to be stretched. Once in the proper position, the stretch is held for 1.5 to 2 seconds, released, and then repeated 8-10 times in a set. AIS has been used by thousands of professional and amateur athletes to increase flexibility and performance while reducing the risk of injury. It is also effective in reducing pain in the human body caused by incorrect posture, injury, and inactivity.