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The concept of stretching a muscle while simultaneously contracting it to build muscle is nothing new:

Chuck Sipes was hanging from a chin-up bar with a weight attached to his waist as his primary lat builder as early as the early 1960s!

John Parrillo was intensely pushing intense fascial stretches to build muscle as early as the 1980s. He used 28 different loaded stretches to help build muscle.

Dante Trudel, inventor of the popular DC training bodybuilding method, became an early proponent of loaded stretching for bodybuilding and was the first one to popularize the use of heavy weights to load stretches.

Successful bodybuilding experts like John Meadows and Dr. Scott Stevenson are also big proponents of loaded stretching for maximum growth.

In the performance world, Jay Schroedder became a huge advocate of long-lasting loaded stretches not only to build muscle, but also to work on proper muscle recruitment patterns.

At about the same time, Tony Schwartz wrote a chapter on this type of training in my book “Theory and Application of Modern Strength and Power Methods”.

All that being said, we must not forget that this type of training actually originates from the training of gymnasts and likely dates back more than 60 years.

The concept is simple: put a muscle (or several muscles) in a stretched position while also contracting it hard. Basically, you are stretching a tensed muscle.  This type of training can increase size, strength, performance and help prevent injuries.  Plus, it gives very rapid results!


Loaded, or tensed, stretching is very effective at stimulating muscle growth. Here are the reasons why it works.


First, you need to understand what mTor does: it is basically the light, where protein synthesis (aka muscle building) is the light. To be even more precise, mTor is like a light switch with intensity settings: the more you turn it on, the more light is being produced. Same thing with protein synthesis: the more you turn on mTor, the more muscle you will build.

Loaded stretching significantly activates mTor because it combines the two types of contractions that have the greatest impact on mTor: accentuated eccentrics and placing the muscle under load in the stretched position.

However, to make these types of muscle actions effective at activating mTor, you need to use a significant external load. A general guideline is that if you can hold a position for longer than 1 minute, the load is insufficient


When a muscle is contracting hard, blood flow to that muscle is restricted. The same thing happens when a muscle is stretched. So loaded stretching, which combines both conditions, creates a very significant restriction in blood flow to the muscle.  This has two effects: 1) it prevents the disposal of metabolites(lactate and hydrogen ions, for example) and 2) it deprives the muscle of oxygen.

Both of these conditions lead to the release of local growth factors that can help with hypertrophy. Specifically IGF-1 an it’s splice variant MGF which are likely the most anabolic hormones in the boy.


When the body senses that the working muscles lack oxygen and can’t get rid of the accumulating metabolites (because blood to the muscles is restricted) it will try to divert more blood flow to the working muscles and to increase cardiac output. If you maintain the stretch and contraction, blood flow continues to be restricted.  When you finally release the muscle tension, there is a hyper-compensation in the amount of blood that flows to the muscles. If that blood is loaded with nutrients (pre-workout nutrition), then you can shuttle more nutrients to that muscle, which can also contribute to protein synthesis. Furthermore, when loaded stretching is performed at the end of the workout, you can get more growth out of the heavier work you performed prior to the stretch and you will also recover faster from your session.


If you use the proper load, you will reach full muscle fiber recruitment very early in the set, and this is amplified by the lack of oxygen (due to blood flow restriction). The body will naturally turn to the glycolytic fast twitch fibers when blood flow is restricted to a muscle, as these fibers do not require oxygen to do the job. As such, you will recruit the growth prone fast twitch fibers early in the set and you will also be able to fatigue them to a significant degree. Even though the fatigue was not imposed due to a dynamic exercise, it still represents a mechanical stimulus for growth.

Note that you reach this level of fatigue while using up a lot less glycogen, which means a lower cortisol response than with regular training, or a less significant increase in cortisol production over what you previously released during the workout.


Loaded stretching also has a very powerful impact on the sensitivity/responsiveness of the IGF-1 receptors. This basically means that not only does it increase IGF-1 release, but it also makes your receptors more sensitive to it!

It is a biochemical hypertrophy bomb!

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