Why sitting the whole day followed by exercise is not ideal

on Tuesday, 11 June 2019. Posted in General Health, Ergonomics, Chiropractic

A Lesson in Anatomy

Why sitting the whole day followed by exercise is not ideal

Before we begin, you need to first understand that we have 2 types of muscles in our bodies; Postural (or Tonic) and Phasic muscles. This is important because it will help you understand:

a. Why taking micro-breaks in between long sitting during the day will improve your exercise regime.

b. Why you might not feel an exercise working in the right places initially and know that they eventually will.

Postural and Phasic Muscles

Postural (or Tonic) muscles are used to sustain our posture while in a standing or sitting position. The phasic muscles on the other hand are primarily for movement. Postural muscles are prone to shortening and tightness whilst the phasic muscles tend to become lengthened and weakened when injured and also during ordinary stresses of daily life.

Why taking micro-breaks in between long sitting during the day will improve your exercise regime.

The problem with sitting for a long period and being inactive is that we will most likely favour using our postural muscle in that environment and this unfortunately also means our brain will disconnect from our phasic muscles.

This is not ideal because when we start exercising again, we won’t be able to use our movement muscles as efficiently as our brain will instead default to getting the postural muscles to do the things the movement muscles should be doing.

A good example of this is people trying to do a squat and is finding that it hurts their back. That is because they have trouble activating the gluteal and hamstring muscles after sitting in the chair for hours so the back muscles are contracted instead (which is not what we want).

This is why it is important to move around throughout the day in the office so your brain is able to use some of those moving muscles and is not set to a default postural muscle usage.

Why you might not feel an exercise working in the right places initially. Push through it and you will feel it work.

As mentioned earlier, phasic muscles are prone to lengthening when they are weak and on top of that our lifestyle causes us to use the postural muscles more often which is why the brain has some difficulty redetecting these phasic muscles initially. Using cues and doing the exercises slower in lesser repetition helps fire up the big phasic muscles and relax the postural muscles.

So don't feel beaten up if you do not feel the right places working at first. The more often you use these muscles, you know they will eventually work.

Remember! Your postural muscles tend to shorten and tighten when stressed and the phasic muscles will lengthen and weaken. So if you are feeling tight on some of the postural muscles listed and having some trouble activating the phasic muscles, it is time to re-evaluate your exercises to improve your condition.

Written By Iris Tan
B.App Sc (Chiropractic)
M.Clin Chiropractic

Reference

https://www.sciencedirect.com/science/article/abs/pii/S1360859298800430