Choosing and Periodizing Repetition Speed for Optimal Muscle Growth

The legendary Russian weightlifter Vasiliy Alexejev supposedly said that your abdominals should be strong enough to stop a bullet.


While Alexejev did not spot a six-pack – neither did he care – he was known for doing 1,000 leg lifts in waist-height water to strengthen his abdomen. Alexejev wasn’t seeking to look good; rather, he was seeking world-class strength and power, as evidenced by his 80 world records in Olympic weightlifting throughout the seventies.

While most will find great satisfaction in being strong, ultimately, (competitive) bodybuilding is about the visual appearance of the various body parts, including the revered six-pack appearance of the abdominal muscles!

However, if your sole focus in your abdominal training is the creation of the six-pack look, you might be missing out, because neurophysiology explains that a strong core helps you and is necessary to lift as much weight as possible in other lifts as well. The more weight you can handle in squats, deadlifts, presses, pulls and isolation exercises, the more you will grow! 

Note: Paul Chek, HHP, defines the core as “everything except the arms and legs.” Most noticeably, the core involves abdominal, back and neck muscles.

This article describes the two key reasons that a strong core is important and five strategies to get more core work into your program without adding training time.


Reason # 1: The core muscles help stabilize the spine during the compound lifts

“Stability is defined as optimal instantaneous axis of rotation of any joint at any time regardless of intrinsic or extrinsic forces.1 If this requirement is not met as heavy loading is applied to the body, unnecessary “wear and tear” (in the form of compression, torsion, shear or strain) is experienced by the passive structures of the body, including joint surfaces and capsules, ligaments, menisci and discs.

“This can quickly lead to stimulation of pain receptors and even low level stimulation of those receptors will exert an inhibitory influence on the motor neuron serving those muscles. Any inhibitory influence on motor neurons involved in the strength exercises will reduce the effect of the strength training.”

Thus, the results of the stability training – the ability to maintain optimal instantaneous axis of rotation – prepares the body for heavy strength training.

This is the methodology proposed by Paul Chek throughout his work.2

Spine stability requires that “there is no movement that should not be there.” For example, the back should not bend during squats or deadlifts. To keep the spine stable during the “big lifts” such as squats and deadlifts, the strength and coordinated action of all core muscles is critical.3


Reason # 2: Strong core muscles enable you to increase intra-abdominal pressure and take advantage of the pneumo-muscular reflex

In his excellent book Power to the People, Pavel Tsatsouline discusses the so-called pneumo-muscular reflex:4,5

“The effect of breathing patterns and the intra-abdominal pressure (IAP) on strength is oddly ignored by most Western strength training authorities. Yet compressed or “power breathing” is one of the most powerful ways of increasing muscular strength in existence! Think of your brain as a music player. Think of your muscles as speakers. Where do you think the amplifier is?—In your stomach. Special baro receptors measure the intra-abdominal pressure and act as the volume control knob. When the IAP bottoms out, the tension in all your muscles drops off. In my stretching book I explain how to take advantage of this phenomenon and make dramatic gains in flexibility overnight. On the other hand, when the internal pressure goes up your nervous system gets more excited and the nerve cells supplying your muscles become “superconductors” of the commands from your brain. So by cranking up the IAP volume knob you automatically get noticeably stronger, in every muscle in your body and in any exercise! [bolded sections are by this author].”

Now that you have some understanding of how a strong and well-functioning core can help your bodybuilding efforts, let’s look at five strategies that can help you create a stronger core without adding training time. Add these strategies to your regular abdominal and back training, and just maybe your abdominals will become strong enough to stop a bullet!


Strategy #1: Use French press diaphragmatic breathing to take advantage of the pneumo-muscular reflex

The purpose of “French press” diaphragmatic breathing (FPDB) is to increase intra-abdominal pressure and thus, by virtue of the pneumo-muscular reflex, to maximize the excitation level of the nervous system to lift the heaviest weights possible.

Contraindications: Performing an expiratory effort against a closed epiglottis during lifting can momentarily triple the blood pressure.6 FPDB involves “pressuring exhalation” that still increases the blood pressure, but most likely not to the same extent. An increased blood pressure may be a risk factor for a stroke, and if you are hypertensive, you must not use FPDB during exercise.

Before engaging in FPDB, optimal neuromuscular tone of the abdominal wall must be established. During conscious attempts, you must be able to move inwards the lower portion of the abdominal wall (at the level of the pelvis).

  1. Assume the correct position for the exercise that is about to be executed. Secure optimal posture with chest slightly up (or out) and chin slightly retracted (the crown of the head is reaching towards the ceiling and the tailbone is reaching toward the floor to create axial extension). “Place your shoulders in your back pockets.” This manoeuvre engages the latissimus dorsi muscles, whose contraction increases tension on the thora-columbar fascia to increase spinal stabilization. Place the tongue in the roof of the mouth behind the front teeth.
  2. While the mantra is to “keep your awareness 100 percent within the body on 100 percent of the body,” four places need special attention: (1) the back of the rib cage, (2) the lower abdominal wall, below and behind the belly button, (3) the hands and fingertips, and (4) the feet. Perform the exercises as you normally would, but as you inhale, feel the force from the breath moving down the back of the rib cage into the lower back and instantaneously “wrapping around” to the lower abdominal wall below and behind the belly button. Place your awareness on the downward movement of the diaphragm as you inhale, and forget about the air moving in through the nose. Make sure that the lower abdominal wall does not expand during the inhalation.
  3. If you have good body awareness, you may be able to feel the breath expanding further into the hands and any implements held as well as the feet, toes and ground.
  4. The inhalation with FPDB is often performed before or during the eccentric or lowering phase of the exercise. Thus, the exhalation coincides with the concentric phase of the lift. The concentric phase typically has a key movement cue – for example, to “push the floor away” (in squats or deadlifts). Push the floor away and simultaneously feel the pressure increase below and behind the belly button. Notice how the pressure forces the air out with a “tsss” sound.

Do not make a conscious attempt to exhale. A conscious attempt to exhale tends to shift body awareness to the mouth, a place where the awareness is not needed. First and foremost, keep the awareness below and behind the belly button and make sure that the abdominal wall still does not expand.


Strategy #2: Create an asymmetrical loading

If you place an extra 5-pound plate on one side of the bar, the asymmetrical loading tends to side flex or rotate the body more than would have been the case with a symmetrically placed load. In the big lifts, such as squats, deadlifts, presses or rows, where the spine is supposed to be stable, your core muscles get extra work by contracting to counteract the effect of the asymmetrical load.

Here are four ways to create an asymmetrical load in exercises that you already know:

  • Use single-arm cable, dumbbell or barbell exercises.
  • With double-arm dumbbell exercises, use a dumbbell that is 5 pounds heavier on one side.
  • With barbell exercises, use 5 or 10 pounds more loading on one side.
  • With barbell exercises, purposely grab the bar 1 to 2 inches off center.


Strategy #3: Have your training partner apply dynamic perturbations to you or to the bar

According to the Collins Dictionary7 “perturbations” means (1) “to disturb the composure of” or (2) “a secondary influence on a system that modifies simple behaviour.”

A more training-specific wording is to repeatedly push or pull – with low force and amplitude – on selected body parts or a piece of equipment held by the lifter. The direction of the pushes and pulls should continuously change, but at the same time be specific to the muscle recruitment pattern desired.

Dynamic perturbations acutely increase electro-myographic activity (a measure of how much your muscles are activated) and stiffness around the joints that experience the perturbations and can thus be an effective strategy to teach the client/athlete to contract target muscles and/or “wake up” sleeping stabilizers – for example, around the spine.8

Dynamic perturbations can only be applied if you have a static component to your tempo in that particular exercise – for example, a 2-second pause in the bottom position of a squat, a deadlift or a press. During the 2-second pause, your partner should gently push one side of the bar in the front-to-back direction. On the next repetition, your partner pushes on the other side of the bar. The pushes should be gentle and allow you to maintain good form. You will be surprised how hard just a little push will make your core contract.


Strategy #4: Lift without a belt

The most important function of the weightlifting belt is to increase the intrathoracic/intra-abdominal pressure to decrease the load on the spinal column. However, the same function is achieved by proper use of the core muscles, including proper breathing (see above). Further, some experts argue that belts decrease segmental stability of the spine.9

If you want the most bang for your buck to strengthen your core optimally while you train the big lifts, it’s therefore recommended to rely on proper use of the core muscles instead of belts. Belts are relevant only to the competing strength athlete (powerlifter) who has the purpose of raising as much weight as possible with no other concerns.

If you’ve used belts for a while, you should progress gradually into “raw” lifting, making sure that you have control of the abdominal wall and master French press diaphragmatic breathing as described above.


Strategy #5: Use core-demanding “big lifts”

Some authorities claim that squats and deadlifts are the best core exercises. Given all the ways that you can train your core, specifically all the ways you can move your spine (front-to-back, side-to-side and rotate), this is a meaningless claim.

Squats and deadlifts are very effective for core strengthening, though, in the particular aspect of core strength called “anti-flexion” (imagine relaxing all your muscles while having the bar on your back. The result would be a collapse, a flexion of the spine).

Core activation in the squat or deadlift increases with (1) the load, (2) the trunk angle compared to vertical (your back is still straight; it’s just “tilted”) and (3) the lifting speed, particularly the speed of the bar just before you reverse the movement. Thus, heavy partials, good mornings or lifts with more speed in the lowering phase are simple ways to increase core activation in your big lifts. Also, not letting the bar touch the floor when you deadlift, but stopping and reversing the movement one inch before the floor, will greatly increase core activation. Further, L-pull-ups and L-dips, where you form an L with your torso and legs, are great variations to increase core activation without adding training time.



    1. Chek P. Functional Stability seminar. (seminar manual). Encinitas, CA: Chek Institute; 2006.
    2. Chek P. Scientific Back Training. (correspondence course) Encinitas, CA: Chek Institute, 1995.
    3. McGill, S. Enhancing lumbar spine stability. In: Ultimate Back Fitness and Performance. Waterloo, ON: Backfitpro Inc.; 2009.
    4. Tsatsouline P. Power breathing: the karate secret of super strength. In: Power to the People. St. Paul, MN: Advanced Fitness Solutions; 1999.
    5. Zatsiorsky V. Strength exercises. In: Zatsiorsky V, Kraemer W (ed.) Science and Practice of Strength Training. Champaign, IL: Human Kinetics; 2006:134-135.
    6. Narloch NA, Brandstater ME. Influence on breathing technique on arterial blood pressure during heavy weight lifting. Arch Phys Med Rehabil. 1995;76(5):457-62.
    7. Collins Dictionary.
    8. McGill S. Stage 2: Building whole body & spine stability. In: Ultimate Back Fitness and Performance. Waterloo, ON: Backfitpro Inc.; 2009.
    9. Chek P. Back Strong and Beltless. Encinitas, CA: Chek Institute; 2006.
    10. Image: