Triphasic Training and Powerlifting


Triphasic Training takes the three phases of a movement (eccentric, isometric, and concentric) and breaks them down into individual training components.  Each phase is trained individually for a period of weeks to months before transitioning to the next phase.  There are numerous benefits to implementing triphasic training into your programming.  First and foremost, it can greatly reduce the risk of injuries in powerlifting by strengthening all three phases of the movement you will be performing on the platform.  Almost all powerlifters train only the concentric portion of the lift, few train the isometric portion of a lift (think pause squats), and virtually no one trains the eccentric portion of a lift.  In his book, Triphasic Training, the author Cal Dietz, explains how the lack of being strong in all three phases of a movement contributes greatly to non-contact injuries we see in sports.  Such as when an athlete plants to change direction and blows out their knee because they have been neglecting two phases of a movement and their body, then, cannot handle the stress being imposed upon it.  Also, think of how many powerlifting injuries occur and at what stage of the lift most of those injuries occur-during the eccentric portion or lowering of the weight.  On top of that, there are numerous physiological adaptations that contribute to greater force production when all three phases of a movement are strengthened.  This is what we be getting into here.


Every dynamic muscle movement begins with an eccentric action.  An eccentric action can be explained as one in which the proximal (closest to center of body) and distal (furthest from center of body) attachments of the muscle move in opposite directions from each other.  This movement is essentially the “lengthening” phase as the muscle is stretched due to forces being executed upon it.  For example, as you jump, your hips dip slightly before take-off, eccentrically lengthening the quads and glutes before take-off.  This eccentric loading of a muscle put in motion a series of physiological events that pre-load the muscle, storing kinetic energy to be used in an explosive, concentric movement.

When you train the eccentric portion of a movement, you are actually training two physiological processes that contribute to force development (which powerlifting should be called force lifting not powerlifting).  One of these processes is one the most powerful human reflex in the body, the stretch reflex.  The other, whose force producing abilities are dependent upon the stretch reflex, is a close second in terms of the ability to produce force and is named the stretch shortening cycle (SSC).

The net force production of the stretch reflex is compromised of the sum of two proprioceptive nerve signals.  The first is muscle spindles which act as neuromuscular stimulators.  The second is Golgi tendon organs (GTO) which act as neuromuscular inhibitors.  While muscle spindles tell your body how hard to contract, Golgi tendon organs (GTO) tell the brain when to relax.  GTO are found within the tendons attaching muscles to bones and unlike muscle spindles which measure changes in length, the GTO measure changes in force being applied to a muscle.  Therefore, GTO are necessary to prevent the muscles from exerting more force than the connective tissues can tolerate.  The GTO is essentially a kill switch to prevent the muscles from exerting more force than they can handle and this prevent serious structural damages to muscles and tendons.

Most people’s GTO appear to have a pre-set kill switch set approximately 40% below what the tendons/muscles can handle before damage occurs.  When you train the eccentric phase of dynamic movement, you are training these proprioceptive structures of the muscle, the muscle spindles, and the GTO.  For you to maximize your force production (amount of weight lifted), you must train in a way that will decrease the inhibitory effect of the GTO while maximizing the excitatory responses from the muscle spindles.

This directly translates to the weaker your ability to handles high levels of eccentric force, the weaker your concentric muscle action will also be.  Meaning, to get stronger on the concentric portion of a lift, you must also get stronger on the eccentric portion (and I would argue the eccentric needs to get stronger first).  Therefore, the goal of the eccentric phase is to improve neuromuscular synchronization of the afferent/efferent neural pathway between the muscle spindle, CNS, and muscle while desensitizing the GTO, allowing you to absorb higher levels of force without triggering an inhibitory GTO reflex (ie missed lift).

Training the eccentric portion of a lift:     

The most effective means of applying stress for you to improve the eccentric qualities outlined above is to perform large, compound movements (Squat, Bench, and Romanian Deadlift) with an accentuated (SLOW) eccentric phase.  The extended time under eccentric tension allows both the muscle spindles and the GTO to adapt and feel higher levels of stress than would be present during normal, dynamic lifting.

It should be noted that eccentric training is extremely taxing on your nervous system because eccentric training recruits fewer total motor units compared to concentric training.  Therefore, this increases the stress placed on each of the recruited motor units which can lead to fatigue.  Also, eccentric training preferentially targets type II muscle fibers (fast twitch) which are imperative for development of anaerobic power but fast twitch muscles also fatigue much faster than type I (slow twitch) muscle fibers.  Because of this, eccentric training should be performed with large, compound exercises at the beginning of a workout.  As you progress in your eccentric training, you should be using the principle of overload (earlier writing) and the training can be moved throughout the workout.

4 rules of eccentric training:

  1. Due to the intense stress placed on you by eccentric training, you should focus on solely large compound barbell movements as your exercises. It is also advised to start with just one eccentric compound movement per exercise to allow your body to adapt to the stress and fatigue.  Once you have trained eccentric movements through several blocks, you can add a second eccentric movement to a workout.  For example, starting with eccentric back squats and finishing with eccentric Romanian deadlifts.
  2. Never perform eccentric movements greater than 85% of your 1RM (1 rep max). And even 85% is on the high side for well-trained athletes.  Most of you would benefit from starting around 70% of your 1RM and doing sets of 5 reps with 6 second eccentrics for 4 sets.  As you progress, a nice model to follow is 75% of your 1RM, doing 4 reps with 4-6 second eccentrics for 4 sets.  Then, move on to 80% for 3 reps of 5 second eccentrics for 3 sets.  Finally, 85% for 2 reps of 5 second eccentrics for 2 sets (see table below).      


85% 5-6 seconds 1-2 1-2
80% 5-6 seconds 2-3 2-3
75% 6-8 seconds 3-4 3-4
70% 6-8 seconds 4-5 4-5


  1. Always have a spotter when performing slow eccentrics or at least spotter arms or catch straps. You need to remember, when you are performing slow eccentrics you are taxing both your nervous systems and your muscular structures, even at 70% of your 1RM. On top of that, slow eccentrics create a lot of time under tension which means you might reach fatigue levels that cause you to miss very quickly and with little warning so it is better to be safe than sorry.
  2. ALWAYS ALWAYS ALWAYS finish an eccentric focused lift with as explosive and forceful concentric movement as possible. You also want your isometric portions of the lift (moment between eccentric and concentric) to be as short as possible.  One of the most important aspects of any performance based athlete is their nervous systems and how fast it can fire.  Every time you transition from an eccentric movement to a concentric movement, your nervous system must change its firing pattern to initiate the next portion of the lift.  So, it is imperative to your powerlifting success that this process is as fluid and seamless as possible.  When approaching the 85% threshold, the bar will not necessarily move quickly; however, it is imperative that you initiate the concentric phase and throughout the concentric phase with as much force as possible every single rep.


Now that you understand the eccentric phase, you are 1/3 of the way to understanding movement patterns.  Knowing how to train and harness the power of the eccentric portion of the lift is useless unless you understand how then to transfer that power to the concentric phase. The isometric phase is probably the hardest to understand or explain but may be the most important phase of a movement.  Essentially, the isometric phase is the energy transfer from the stored eccentric phase into the explosive, concentric phase.  The problem with this phase is for well-trained athletes it is almost instantaneous in time.  It should be noted that we are not talking about isometric as in static holds, but as the point where you initiate your concentric contraction of the muscles.  This occurs for the split second where force being exerted on the muscle equals the force being imposed on it by the weights.  Therefore, when you start to think of the isometric phase as a contraction, you should then understand that it is trainable just like the eccentric and concentric phases of the movement.

Similar to the eccentric phase, the isometric phase has two neurological processes that need to be trained to maximize the force transfer from the eccentric to the concentric muscle contractions.  There are two options when muscles need to increase their level of force production: motor unit recruitment which increases the number of muscle fibers that fire.  And/or rate coding which increases the rate at which each of the fibers fire and thus increases muscular tension.

Motor unit recruitment can be thought of as the sledge hammer game at a carnival.  You swing the sledge hammer and hit the base which shoots up a weight lighting up the pole higher and higher the harder you hit the base.  The same basic thing occurs during the isometric phase.  The more force that is applied eccentrically (the sledgehammer), the higher the resulting level of motor unit recruitment must occur (the higher the lights go up the pole) to decelerate and stop the load.

Rate coding is the primary responder when a muscle needs to build intramuscular tension quickly to overcome the load be imposed.  It is important to understand that rate coding is a response variable and the muscle must be taught to respond to a situation through training.  By increasing the rate coding of its isometric motor neuron pathway, the muscles build tension very quickly, bringing the load to a stop.  It is also very important to understand that having an inefficient isometric contraction results in less force available for absorption and subsequent decrease in force output during the concentric contraction.

Training the isometric portion of a lift:

Just like eccentric training, isometric training should be performed at the beginning of a workout.  It is important to do your isometric training at the beginning not only to keep fatigue minimal while training the isometric portion of the lift but also because it can have a potentiation effect on the remainder of the workout.  Meaning, the high level of intramuscular tension that is created through isometric training can carry over throughout the rest of the workout because of the greater number of motor units that are turned on from this training.  It should also be noted that unlike eccentric training where heavy compound barbell movements are all you want to train eccentrically, accessory work done using isometric training can increase the net affect more than just doing isometric training using heavy compound movements alone.  For example, after training bench press isometrically, it is not a bad idea to also do a few sets of say close grip bench training it isometrically.

Finally, like eccentric training, while training isometrically you want the concentric portion of the lift to always be as dynamic and explosive as possible.  Lower the weight as quickly as possible (also key), stop the load and hold it for 2-6 seconds, and the concentrically explode the weights back.  Also, you again do not want or need to train isometrically more than 85% of your 1RM (see table).


85% 3-4 seconds 1-2 4-5
80% 3-4 seconds 2-3 4-5
75% 4-5 seconds 3-4 3-4
70% 4-5 seconds 4-5 3-4


4 rules of isometric training:

  1. Hit the isometric portion of the lift as fast and hard as possible. The main goal of performing isometric work is to teach your physiological structure to absorb energy instantaneously and efficiently.  Often, an athlete will hit the “hole” as hard and fast as possible for the first 85 degrees of the movement and then slowly stop over the next 15 degrees.  This drastically reduced the force needed to be absorbed to stop the eccentric portion of the movement.  You must hit the “hole” like a rock being thrown at the ground.  You must stop the load within two or so degrees not 10-15 degrees.
  2. Use the que “squeeze” while performing isometric training. So, as you hit the isometric contraction you should think about squeezing your muscles as hard and as forceful as possible.  A good way to get this motor pattern firing is to perform some warm up sets without a load.  For example, squat down as fast as possible, and then squeeze your glutes and legs as hard and forceful as possible.  Once you get the mind/muscle connection working, you can start using a load.
  3. Always use a spotter or spotter arms. Remember when performing isometric training you are not only squeezing your muscles as hard and forceful as possible, you are also exploding as forcefully as possible on the concentric portion of the lift.  Therefore, it is not uncommon after a few reps to start your concentric contraction and not have the weight move an inch.  Therefore, it is always better to be safe than sorry.
  4. Always finish an isometric lift with an explosive and forceful concentric movement. All athletic movements are triphasic and the neurological pathways that signal these contractions are entirely different and independent of one another.  If there is any lag in time between these stages, energy is lost, decreasing the help of the stretch reflex and SSC to power development.  Therefore, the intent to accelerate the bar, building intramuscular force quickly, and recruiting intermuscular recruitment neutrally, must be trained every time you perform a repetition.


The concentric phase of a lift is the sexy, how much ya bench, phase of dynamic movement.  The concentric portion is the measuring stick used to evaluate your strength.  Unfortunately, no one ever asks how much can you lower eccentrically in the squat or how much can you hold isometrically in the bench, it is always how much do you lift bruh?  Specifically, as it relates to powerlifting, the concentric phase is the measure of your rate of force development (RFD).  Again, this is why powerlifting should really be called force lifting.

By definition, the concentric phase of a movement is when the proximal and distal attachments of a muscle move towards one another.  It refers to a muscle producing enough force to overcome a load.  It is also important to remember that the amount of potential energy stored for a concentric movement is dependent on the preceding eccentric and isometric contractions.  The RFD of the concentric contraction is aided by the combined force of the stretch reflex and SSC.

The true importance of training the concentric phase is the synchronization of the entire triphasic muscle action-maximizing force development from the proceeding eccentric and isometric contraction into a unified explosive and forceful movement, while minimizing the amount of stored energy lost through the phases.  In order to gain the benefits of the stretch reflex and SSC, you must train the neurological and physiological systems of the concentric phase to improve the rate of intramuscular and intermuscular coordination; motor unit recruitment, rate coding, rate coupling, synchronization, inhibition, and disinhibition.

You cannot take the concentric phase for granted.  While it is the most trained phase of the triphasic movement pattern, it is rarely every trained or practiced in a way that maximizes the use of kinetic energy absorbed by you.  You may spend weeks learning how to eccentrically and isometrically absorb energy, but if you fail to properly train your body how to unleash this energy, it was all a waste of time and effort.

How to properly train the concentric phase:

This is fairly straight forward but very few people put any emphasis on it while training-TRAIN FAST or as fast as you can move the weight based off the load.  The goal of concentric training is to maximize intermuscular coordination, increase motor unit recruitment, and maximize force production.  Therefore, when training specifically the concentric phase each rep should be done as ballistically as possible.  The most important item to remember when performing dynamic, concentric focused work is to push as hard as possible against the bar, and driving the bar through the entire range of motion.  Many people, myself included, often slow once they get out of their sticking point.  If you watch top tier elite powerlifters, they generate as much force as possible through the entire range of motion.  Again, the focus here is to develop a powerful and synchronized concentric contraction.  These reps need to move as fast as possible while maintaining form and all three phases of the lift need to move as fast as possible.  This is where training the other two phases now combine together and you create one strong, fast movement.

97.5% As fast as possible 1 1-2
95% As fast as possible 1 2-3
90% As fast as possible 1-2 3-4
85% As fast as possible 1-2 4-5
80% As fast as possible 1-3 4-5
75% As fast as possible 1-3 4-5



I have found that most all powerlifters fall into the trap of focusing solely on the concentric phase of the lift.  After all, the squat, bench, and deadlift are all measures of concentric force production.  Few powerlifters focus on the isometric portion of the lift by doing pause lifts.  Even fewer powerlifters focus on the eccentric phase of the lift, even though this is wear numerous injuries occur.

This is doing a disservice to you as a lifter.  Powerlifting is not about power but about the ability to generate as much force as necessary.  To get the most force possible out of a movement requires coordination of dozens of muscle groups, hundreds of motor neurons, and thousands of muscle fibers.  The potential of these can only be expressed through training all three phases of the movement.  Again, there are numerous physiological adaptations that contribute to greater force production when all three phases of a movement are strengthened.  Therefore, if you want to fully exhibit your force production potential on the platform, it is advised to train all three movements known as triphasic training.

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