The Physiology Of Weight Training

The Physiology Of Weight Training
The Physiology Of Weight Training

This is an aside to explain the physiology of the article “Weight Train Once a Week!“. It’s a further explanation of how we came up with The Ten Principles of “The WOW Method”. As well, it will help you to understand why you only need to weight train once a week.

The Physiology Of Weight Training | Why Weight Training Once A Week Works!

  1. Training to complete muscular exhaustion ensures that you’ve exhausted all the muscle fibres in the targeted muscle group.
  2. By exhausting all the muscle fibres in that particular muscle group, you’ve stimulated each fibre to build new contractile units over the next week.
  3. The muscles actually need 6 to 7 days to recover completely. Training them more often interferes with the recovery process & causes inflammation.
  4. New contractile units in each & every muscle fibre … This equates to stronger & bigger muscles!

(Note: The following explanation of physiology has been greatly simplified out of respect for the layperson’s time.)

Muscle Physiology

The Physiology Of Weight Training
Biceps Brachii muscle

The human body is made up of cells. The cells that make up muscle tissue are known as muscle fibres. For the most part, muscle fibres are thin, long & cylindrical. They run the entire length of the muscle attaching to tendons at either end. (Tendons are tough, non-contractile tissue that connects your muscles to your bones.)

The Physiology Of Weight Training
Muscle Fibres

Each muscle fibre contains hoards of contractile units. These contractile units are microscopic.

Your brain will fire a signal down a motor neuron (the nerve) to your muscle. This will cause all the all the contractile units within your muscle fibre to contract “in concert”. This shortens the muscle thereby moving your body (& lifting that dumbbell).

One muscle fibre can’t lift the weight of a dumbbell!

This is why one motor neuron will stimulate many muscle fibres at once. Depending on the muscle, one motor neuron will transport the signal to a few hundred (or even a few thousand) muscle fibres.

 A motor unit is made up of a motor neuron (the nerve) & the select muscle fibres triggered by that motor neuron. There are many motor units within each muscle.

A Set Should Continue Until Complete Muscular Exhaustion 

The Physiology Of Weight Training
Training to complete muscular exhaustion ensures that you’ve exhausted all the muscle fibres in the targeted muscle group.

Repetition (rep) is the controlled lifting & lowering of the weight through the full range of motion. Set consists of several repetitions without resting in between.

Complete Muscular Failure or Exhaustion means continuing to perform repetitions until the point of momentary muscular failure where, although you are engaged in lifting the weight (eg. bicep curl), the arm will no longer move because all motor units have been exhausted.

Note: It is not absolutely necessary to lift to the point of complete muscular failure, it’s just the most efficient way to gain strength & size.

Henneman’s Size Principle: states that under load, motor units are recruited from smallest to largest. This means that slow-twitch, low-force, fatigue-resistant muscle fibers are activated first. Then fast-twitch, high-force, less fatigue-resistant muscle fibers are activated second.

During a weight training set, the smallest (slow twitch) motor units are recruited first. As the set progresses & you continue your reps, more & more motor units are recruited to continue lifting & lowering the weight.

Slow Twitch Motor Unit is comprised of a nerve & many slow twitch muscle fibres. These fibres fire slowly. Therefore they are able to maintain continuous muscle contractions over extended periods of time.

Then comes that point during your set when it becomes very difficult to continue lifting the weight. This is when the largest (fast twitch) motor units are recruited.

Fast Twitch Motor Unit is comprised of a nerve & many fast twitch muscle fibres. These fast twitch fibres fire rapidly, therefore fatigue quickly.

Taking the set to complete muscular exhaustion ensures that you’ve exhausted all the muscle fibres (both slow twitch & fast twitch) in that particular muscle.

This is why the last few reps before muscular failure are the most important!

To ensure each muscle fibre has been exhausted by the end of the set (& therefore stimulated), the repetitions must be kept between 14 & 20 by the time you achieve complete muscular failure.

Exhausting A Muscle Fibres Stimulates That Fibre to Build New Contractile Units.

The Physiology Of Weight Training
By exhausting all the muscle fibres in that particular muscle group, you’ve stimulated each & every fibre to build new contractile units over the next week.

Think of a muscle fibre as a long rowboat with lots of rowers. After a workout, the boat is ripped down, then built back up bigger & stronger & with more rowers!

The same with muscle. Each muscle fibre is ripped down & built back up with more contractile units.

New contractile units in each & every muscle fibre … This equates to stronger & bigger muscles!

Muscles Need 6 to 7 Days to Recover Completely.

Training your muscles more often will interfere with the physiology of the recovery process. This causes inflammation & eventually, injury.

The building of new tissues within the body can only happen at a set rate. At this set rate it usually takes a full six to seven days to:

  • Dissipate the fatigue & inflammation.
  • Repair the tears in the muscle fibres.
  • Build new contractile units within the muscle fibres.
  • Strengthen the tendons, ligaments, fascia & bones. This is so that they are strong enough to support the stronger muscles.

Even if seven days seems like a long time, rest assured, you will not start to lose muscle during that time (unless you diet).

To recap: Weight train each muscle group to failure. This exhausts & therefore stimulates all muscle fibres to build new contractile units over the next 7 day period. This’ll give you stronger, larger muscles without inflammation.

Credentials

Evidence based research has become so de rigueur that every theory of physiology is expected to be based upon it. However, I can’t help but notice that with just a bit of research on Google, any theory of physiology can easily be either proven or disproven.

I’ve included several studies, or articles based upon studies. However, The WOW Method (created by LEONG Orthopaedic Health) is mostly based upon the last twenty years of results with our clientele.

– LEONG Orthopaedic Health

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