InTension is the conscious and strategic attempt to augment the tension generated in the musculature involved in the execution of an exercise. In essence it is the intentional “tightening” beyond what is actually required by the external source of resistance as it inherently varies throughout the range of motion.

InTension is one of four methods of manipulating intention during the execution of exercise taught by RTS®, the Resistance Training Specialist® Program. It was developed in 1987 by Thomas C. Purvis. One of the first delivery systems or cueing techniques for InTension was the “4 Step Rep”, also developed in 1987.

Importance in Exercise

InTension is a key step in moving away from traditional External Performance oriented exercise which is monitored and measured externally, often at the expense of the body, health, and fitness. It is a vital skill in the delivery of Internal Performance oriented exercise wherein the activity is monitored and measured through the interpretation of internal indicators, and everything is Client-Defined.

InTension® can be used:

  1. As a tool for learning, enhancing, and utilizing control
  2. As a means of improving intra-joint stability via the enhanced co-contraction of the antagonists, e.g. countering anterior shear in an ACL deficient knee
  3. As a measurement tool for determining one’s range of control as it varies with load and resistance profile
  4. As a measurement tool for determining incremental increases in speed without sacrificing control
  5. As a measurement tool for determining the end of a set based upon controlled tension (final effort) and the perception of the associated sensations
  6. As a means for reducing the potentially exponential increase in joint and tissue forces associated with haphazard acceleration, and often of greater importance to individuals with pain or pathology, uncontrolled deceleration
  7. As a means of increasing or adjusting effort (percentage momentary output) on all reps prior to and including the degree of final effort associated with the set-ending final rep


While learning and using the skill of InTension the speed of execution is reduced to enhance the opportunity for control and awareness at every point in the range. Because the muscular tension is augmented in the agonist while not allowing the normal increase in speed associated with greater muscular tension, recruitment of the antagonists is orchestrated proportionally to act as internal resistance. This co-contraction has shown to enhance the experience of specific individuals as determined by one’s idiosyncratic goal/s, needs, abilities, and tolerances.

The degree of InTension will vary with progressive loads. Lighter loads allow the opportunity for greater degrees of InTension. Heavier, near max loads allow for lesser degrees InTension®. The two experiences are very different and both should be explored as progression allows (tolerance, control, output, etc.).

Note: Is seems as though some individuals become excessively fond of, almost “addicted” to the sensations of muscular contraction that can only be generated with lower loads and higher degrees of InTension. At some point it is likely to be beneficial to progress toward high loads at the expense of this sensation. This should not be at the expense of control and a degree InTension can be maintained, but the sensation will be very different. The degree of InTension employed should be a matter of Strategic Variation® to which one returns periodically simply for variation or for a required reinforcement of control.

The greatest challenge to acquiring the skill of InTension is the innate human desire to perform an exercise in such a manner as to actually reduce the resistance via tension-inertial timing (i.e. launching), or by using joint movement/musculature that is unrelated to the G.O.T.E. (goal of this exercise) and should remain virtually static. Alone or together these behaviors are colloquially called “cheating,” which could be considered “the skill of making things easier” while the purpose of exercise is appropriate challenge to the body, for which one should strive to learn “the skill of making things harder”.


Mindful Exercise Is Not the Exclusive Domain of Yoga and Pilates

This level of enhanced awareness utilized in the muscle/body focus cueing is often confused with trying to emulate yoga or Pilates. It is easy to make this assumption because the primary difference between yoga or Pilates and traditional strength training is not the apparatus or the philosophy. Of course the movements and loads utilized are typically very different, but it is the neurological intention with which the movements are performed (or lack thereof) that truly separates these activities.

Focus and intention as directed by a quality Pilates or Yoga instructor is turned inward toward body control and internal monitoring of positions, motions, and limitations.   Traditionally, the focus and intention when lifting a weight is, much like a sport, typically directed toward the external outcomes, e.g. the movement of the load, and often at the expense of the body. InTension is but one strategic means for transforming a wide variety of resistance exercises into mindful activities.

It Is Not an “Isometric”
Upon initial introduction, some say “it’s like doing an isometric” during the exercise, but because the muscles are changing length throughout the range while intentionally augmenting their tension, it is in no way isometric. It is similar in experience due in part to the fact that isometrics are often produced by using the antagonistic musculature as resistance to prevent motion.

If the 4 step rep is employed to cue InTension, then the top and bottom of the rep will in fact be isometrics.

InTension “Will Slow You Down”

InTension will certainly require control and control often requires slower movements until mastery is achieved. But the industry’s blind and unbridled concern for “speed” is actually misguided and quite disturbing as it stems from the unquestioned relationship between exercise and sports performance and the self-serving sports bias of many trainers.

There are many prerequisite questions, such as how is speed defined? Speed of movement or speed of contraction? But the first question should always be aimed at determining the primary context influencing factor: who are we training and what is his/her goal? A grandmother? An acute knee patient? A client with chronic shoulder dysfunction at wits end looking for improved intra-joint stability in order to change a light bulb without recurrent gleno-humeral subluxation?

Speed is relative. Speed should be progressed. Speed should not exceed accuracy or come at the expense of internal integrity. Although all research is/should be suspect, and we should refrain from extrapolation-based conclusions, there appears to be considerable evidence that intention is a major factor in the development of speed.

Consider this quote from Jack Roach (head coach, US National Junior Team, Olympic Training Center) who has been responsible for cultivating such Olympic talents as Michael Phelps through their developmental years: “The only way to swim fast is to have great technique. The only way to develop great technique is to swim slow.”

Intention: Internal vs. External?
In the “movement training” fields we are often taught to refrain from using muscle/body focused instructions or cues in favor of motion, target, or object focused cues. The latter is often deemed a superior way to allow the body to orchestrate a motor recruitment solution without conscious dictatorial influence.

This conflict should not become an “either/or”, rather a strategic choice based upon who is being considered, his/her goals, needs, and tolerances. Ultimately, the ownership of one’s body including one’s skilled awareness of, interpretation of, and respect for internal signals (that sports and “movement bias” inherently ignore) has life-long value. So if a client is just trying to improve quality of life, muscular control, strength, or size, InTension can be an invaluable and indispensable tool when used appropriately.