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The Flexible Periodization Method


Achieve faster results for inury prevention, body comp and performance by developing the six sides of the trunk from the inside out and the ground up.

Are isolation exercises for the core necessary,
or is it enough to just do the big lifts?

At the peak of the progression are integrated trunk strength and power exercises. Here, single arm split jerk
(the side flexor lineage) is demonstrated by 15 time Kettlebell World Record holder, Jennifer Hintenberger.

A recent survey indicates that most coaches believe that trunk (core) training is necessary and upright loaded exercises are more effective than traditional core stability exercises.  

However, especially from the field of back rehabilitation, there is support for first strengthening individual, weak muscle groups before challenging these muscle groups to work in an integrated fashion during multi-joint exercises. 

Trunk training is already extensively researched, but the essential information is scattered in many different places and often presented in a contradictory manner that makes it difficult to understand and apply effectively. 

By providing a comprehensive, unbiased map for building the trunk from the inside out and ground up Progressive Trunk Training helps your athletes or fitness clients reach their chosen destination faster by offering the essential aspects of trunk training in ONE place. 

  • Prevent back pain caused by lack of trunk stability

  • Build a great looking trunk, not just the six pack

  • Improve sport performance 

Great presentation. Well organized. Very passionate speaker.
 2019 CPTN Conference delegate

He is nice and slow and methodical – easy to follow and good flow. 
2019 CPTN Conference delegate

The Progressive Trunk Training program is the most comprehensive
trunk training guide that encompasses pelvic floor contractions
and ends with whole body power moves.

In Progressive Trunk Training Program you will learn: 

  • 4 functions of the trunk relating to exercise and recovery

  • 5 stages of progressive trunk training

  • 8 categories of trunk training

  • 4 lineages of trunk training

  • 7 different breathing techniques from ancient martial arts and modern science to activate specific trunk muscles

  • 4 different sounds that activate the trunk muscles

  • 3 targeted cues for “pulsing contractions” to achieve super stiffness

  • 3 key features of a stability ball

  • 9 types of equipment integrated in the program

  • Videos featuring trouble shooting techniques of key exercises.

  • 120+ exercises, most of them NEW combination exercises

Here is an excellent, fairly non-technical way to demonstrate the role of stability,
performed by Shea Pierre, founder of Pierre’s Elite Performance

You may have seen some of these specific methods and exercises before, but not the way Progressive Trunk Training has organized them systematically in one program.

Dynamic Pertubations applied through a band is effective and fun. See it here,
demonstrated by Andrea Lee McMillan, owner of Andrea Lee Fitness.
  • Enhanced motor learning through application of variable and random training.

  • The unique and extensive use of touching, but not resting on the ground, to optimize muscular activation while minimizing disc pressure.

  • Unique and extensive use of the client’s own hands to enhance muscular activation.

  • Common exercises that are likely counter-productive to the athlete-client (and why)

  • Scientific progression on instability (Section 6).

  • The most overlooked error in Front Planks and how to fix it (Section 6).

  • The “Big 3” of Rotational Power (often overlooked or incorrectly executed).

  • The KB Swing as a trunk training tool + research-based comparison of the Russian vs. American Swing.

  • Why just doing the big lifts is not enough for a complete development of the trunk.

  • The FPM way of using straps or lifting belts to enhance the work done rather than as a crutch (if you choose to use it).

  • How to do Sit Ups safely (if the athlete-client really needs it).

  • The C.A.D approach (Cluster Training with Auto Regulation and Drop Sets).

  • Strategic selection of dependent and independent variables to maximize block specific training adaptations.

  • The unique role of the external oblique muscles as anti-flexors of the spine.

What will the FPM Progressive Trunk Training Specialist
distinction do for you?

  • Help any injury free client progress from the most basic to the most advanced trunk exercises to remain pain free, build muscle or improve sport performance.

  • Help you make even better use of the trunk exercises and methods that you already know.

  • Provide a framework to allow you to experiment and apply your own style of training effectively.

  • Be more confident to discuss topics surrounding trunk training with clients or colleagues.

kstudiesweb.jpgA Master Degree in Exercise Physiology + 26 years of working with world class and Olympic Athletes
(27 different sports total) + 100 research studies = New and more effective trunk training tactics

The Progressive Trunk Training Specialist Program is rich in content. It consists of a 140-page manual with 7 sections, 30+ pages of supporting documents and 161 video clips.


The Progressive Trunk Training manual consists of 

Section 1: Primary Training Targets in the Long-term Development of the Trunk
Section 2: Categorizing Trunk Exercises: Anatomy, Biomechanics, Start Position
Section 3: Progressive Trunk Training Map Overview
Section 4: Why Start with Establishing Optimal Breathing Patterns?
Section 5: Foundational Stability
Section 6: Advanced Stability 
Section 7: Trunk Strength and Power
Appendix 1: Selected Instructional Scripts for Section 4b
Appendix 2: Foundational Stability Stage. Scripts and troubleshooting               
Appendix 3: Framework for isometric hold challenge
Appendix 4: Spinal Pump Breathing

Four supplementary documents also accompany the course materials. 

  • The Seven Blocks of The Flexible Periodization Method

  • Break Down the Set to Build Up Strength

  • The Tempo Code

  • The 4 Ways to Flatten the Abdominal Wall with Walking and Targeted Deep Breathing

What is my next step? How can I become an
FPM-Progressive Trunk Training Specialist?

Get the online course and start learning today.

Complete  Progressive Trunk Training Online

The very close grip barbell curl is a great example of the unique aspect of the abdominals as anti-flexors
of the spine. See it performed by Mike MacKinnon, owner of Fit In 20, Inc.

Attend a live workshop.

The Progressive Trunk Training Specialist program is offered in 4 live formats complemented with self study of the manual and videos.

Intensive - two 7-hour days

Fast Track - two 1/2 day live sessions in one day

Hybrid - 1/2 day live (one component - sections 4 &5 OR 6& 7)

One-on-oneFast Track or Intensive offered at your location in a live setting (5 hrs). Contact us for schedule and pricing.

Our exclusive group sizes and interactive assignments help you to immediately apply the material to your athletes/fitness clients.


Aug. 6, 2022 - 9:30am-5:30pm London, ON, Canada

Progressive Trunk Training registration

Not sure that the FPM Progressive Trunk Training Specialist is for you?
Check out an excerpt from the manual before you make your final decision.

Learn more about Progressive Trunk Training.
Download an excerpt of the Progressive Trunk Training manual.

Side flexor lineage foundational stability: There should be little to no movement in the spine when the athlete-client turns from one side to the other during side planks. Asking the client to “show me a good front
plank” in the middle, greatly enhances the quality of the execution.

Here is an example of "Different but the same" demonstrated
by Riaz Aziz, owner of RIAXION.

Can I learn anything from the
FPM Progressive Trunk Training Specialist? 

Take this quiz to find out! 

The questions are pulled from the certification
exam and you will receive your result right away. 

There is no charge.

PTT free quiz

Workshop Attendee Testimonials

Excellent! I really enjoyed the course. – 2019 CPTN Conference Delegate 

Excellent as always, so knowledgeable and fun. – 2019 CPTN Conference Delegate 

Always enjoy his sessions. – 2019 CPTN Conference Delegate.

 Copyright © 2007-2023 Yes To Strength and Karsten Jensen. All rights reserved. 

All information contained on is intended for use by individuals who are healthy, injury-free adults aged 18 years and older who possess sound knowledge and skill execution of strength training exercises and their application and a thorough understanding of proper exercise technique and their application. We urge you to exercise care and caution when attempting any of the exercises, combinations, tips and strategies mentioned and to seek competent help and counsel from trained medical or fitness experts before beginning any new exercise program, or if you have any questions about your health. and Karsten Jensen are neither responsible nor liable for any harm or injury resulting from use of the information described herein.