Getting to the V: Training with Triphasic

Athletic performance is a blend of science and strategy, and few training methodologies encapsulate this as effectively as Triphasic Training by Cal Dietz. This innovative approach dissects human movement into three primary phases of muscle action: eccentric, isometric, and concentric. By isolating and optimizing each phase, athletes can achieve unparalleled strength, power, and efficiency. This article delves into the principles of Triphasic Training, its scientific foundation, and its practical application across various sports.

“All dynamic muscle action is triphasic” – Verkhoshansky & Siff 2009

The term ‘Triphasic’ refers to the three phases of a dynamic muscle action:

Eccentric Phase – A muscle action that occurs during the lowering phase of a movement, during which the muscle lengthens. The eccentric force is responsible for controlling the deceleration of a load.

Isometric Phase – A muscle action that occurs between the lowering and upward phase of a movement. Muscle length remains constant as the contractile force is equal to the resistive force. This is the point at which the load changes direction.

Concentric Phase – A muscle action that occurs during the upward phase of a movement where the muscle contracts, accelerating a load and shortening in length.

The 4 Essential Principles

Due to the high concentrations of stress needed for performance qualities to improve, an athlete can't effectively train for strength, speed, and power all together. For most anaerobic sports the athletes need all three attributes but there is a sequence of parameters that will allow for maximum transfer to sport: General Fitness, Max Strength, Strength endurance and power, Max Speed. Within this block training system there are three essential points via concentrated loads, specificity, and systematic implementation of training means.

1. High Training Loads - "Stress your athletes and stress them often"

2. Focus on minimal number of training targets - Keep the main thing the main thing

3. Consecutive development of training targets - Specific order matters for continued development, as you improve one performance metric it will come at the expense of another.

4. Residual Training Effect - "the retention of changes induced by systematic workloads beyond a certain time period after the cessation of training"

   
   

Exploring the Physiology of Triphasic

Eccentric Phase

When referring to the eccentric phase of a movement, the training focuses on two physiological processes that contribute to force development: the stretch reflex and the stretch shortening cycle (SSC). The stretch reflex involves two proprioceptive nerve signals: muscle spindles and Golgi tendon organs (GTO). Muscle spindles stimulate muscles and relay information to the brain, increasing muscle contraction with greater force. Conversely, the GTO inhibits neuromuscular activity, promoting muscle relaxation to protect fibers when tension is excessive. Eccentric training aims to enhance muscle spindle and CNS synchronization while desensitizing the GTO, improving force absorption without triggering the inhibitory reflex. The SSC absorbs kinetic energy in muscles and tendons, storing elastic energy for the concentric phase. This training is linked to better sprinting, jumping, and change of direction performance.

Isometric Phase

The isometric contraction involves two neurological processes: motor unit recruitment (MUR) and rate coding. Enhancing these processes helps athletes generate more force quickly. MUR concerns which and how many motor units are involved in muscle contraction, following the size principle where motor units are recruited sequentially based on thresholds. Rate coding is the speed at which motor units are fired (2). Since the intensity of a motor neuron signal remains constant, the nervous system must elevate the signal frequency to enhance the contraction force. Rate coupling involves the synchronization of the contractile mechanism and is part of the isometric phase because of the high levels of intramuscular tension required to halt the eccentric lengthening of a muscle at very high speeds. To maximize force potential an athlete must be able to efficiently produce thousands of muscle twitches during the isometric phase of a dynamic movement (4). Through isometric strength training athletes can improve motor unit recruitment, rate coding and rate coupling leading to a more efficient neuromuscular action and a greater a rate of force development (RFD) (5).

Concentric Phase

The concentric phase measures an athlete's RFD and is facilitated by the stretch reflex and SSC. Training this phase aims to synchronize triphasic muscle action, utilizing energy from the eccentric and isometric phases. Mechanisms are divided into intramuscular coordination (motor unit recruitment, rate coding, rate coupling) and intermuscular coordination (agonist/antagonist muscle inhibition/disinhibition, and synchronization of neuromuscular mechanisms).

"The key to improved sport performance is producing more force in less time." - Cal Dietz

"The entire point of the triphasic method - learning to eccentrically and isometrically absorb energy before applying it in explosive dynamic movements"

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Periodization: Structuring the Training Plan

A distinctive aspect of Triphasic Training is its organized periodization. Athletes advance through each phase in concentrated 2–3-week intervals, ensuring optimal adaptation. The eccentric phase utilizes high loads with controlled tempos to enhance strength and stability. The isometric phase involves moderate loads with static holds to improve joint integrity and neural efficiency. The concentric phase uses lighter loads focusing on speed and explosiveness. In section 3, Dietz offers a variety of example exercises for each phase, enabling you to customize your approach within the system as it aligns training cycles with competition schedules, allowing athletes to achieve peak performance at the ideal time.

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 Dietz explains how to sequence the eccentric, isometric, and concentric phases within a periodized training cycle. He emphasizes how to manipulate variables like intensity, volume, and rest periods for optimal results.

Week 1-2	GPP (General Physical Preparedness)	Assess the Athlete	40-80% Load
Week 3-4	Eccentric Block	High Load | Slow Tempo	60-85% Load
Week 5-6	Isometric Block	Moderate Load | Static Hold	60-85% Load
Week 7-8	Concentric Block	Athlete Peaking | Max Velocity	30-95% Load
Week 9	Test	Sprint, Vertical, Lift

Advanced Techniques to Amplify Results

Dietz incorporates several advanced methods to further optimize the Triphasic Training system. Contrast training, which pairs heavy lifts with explosive movements like squats followed by box jumps, boosts neural activation. Cluster sets, with short rest intervals within a set, maintain high power output. Accommodating resistance, using bands or chains, varies resistance throughout the range of motion. Plyometrics focus on explosive, dynamic movements to reinforce concentric power.

Conclusion: A Science-Driven Path to Excellence

Triphasic Training is not merely a training program; it is a scientifically based system crafted to enhance athletic potential. By focusing on and optimizing the eccentric, isometric, and concentric phases of muscle action, this methodology enables athletes to achieve optimal performance. I highly recommend picking up his book to dive into the wealth of information he provides. Plus, if you’re eager to learn even more about the system, he has just launched Triphasic Training 2!

Resources:

1. Verkhoshansky, Y., & Siff, M. (2009). Supertraining. Rome, Italy: Verkhoshansky.

2. Baechle, T., & Earle, R. (2000).Essentials of strength training & conditioning (2.ed.). Champaign, Ill.: Human Kinetics.

3. de Hoyo, M., de la Torre, A., Pradas, F., Sañudo, B., Carrasco, L., & Mateo-Cortes, J. et al. (2014). Effects of Eccentric Overload Bout on Change of Direction and Performance in Soccer Players.International Journal Of Sports Medicine, 36(04), 308-314.

4. Dietz, C., & Peterson, B. (2012). Triphasic training. Hudson, WI: Bye Dietz Sport Enterprise.

5. Burgess, K., Connick, M., Graham-Smith, P., & Pearson, S. (2007). Plyometric vs. Isometric Training Influences on Tendon Properties and Muscle Output.The Journal Of Strength And Conditioning Research, 21(3), 986.

6. Cal Dietz and Ben Peterson, (2012). Triphasic Training

 Nathan Albright is the owner of XI Sports Performance, where he works with youth, high school, and college-level athletes offering a wide variety of training with various sports, including Soccer, Football, Basketball, Baseball, Volleyball, and more. Nathan has a BSc. in Exercise Kinesiology from the University of Toledo and currently resides in Northwest Ohio.