Gym Users – Are you OVER-training the PECS?

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If your gym workout is giving you neck pain and shoulder pain, you could be over-training your pectoral or chest muscles. The key is a balanced training program that focuses on several muscle groups to prevent muscle imbalance developing and the consequent dysfunction.

Muscle imbalance leading to dysfunction

The effects of over-developing one muscle group i.e. your chest muscles (pectorals) in the gym, whilst neglecting your back muscles, often affect your posture resulting in neck, back, and shoulder pain

To understand why this occurs, you must be familiar with the notion that most joints in our body have two or more separate and opposing sets of muscles acting on the joint. Take the elbow as an example.

When the biceps contracts and shortens, it bends the elbow joint. As the elbow bends, the opposing triceps, must relax and lengthen to allow this movement to occur. And vice-versa, for the elbow to straighten; the triceps contracts and shortens and the biceps must relax and lengthen.

To gain a well-rounded physique you must consider strengthening more than just one, if not all the muscle groups. An overdeveloped muscle (group) will create more tension on one side of the joint. Overdeveloped muscles are also often tighter (shorter) than normal. The balance between muscles at the joint is lost, pulling the joint away from its mid-line and changes the angle of rotation at the joint.

The shoulder joint is more complicated, but the same principle applies

From personal experience as a physiotherapist, one of the most common mistakes in the gym is over-training the chest muscles. This causes an imbalance between the muscles at the front of the body and those at the back. The shoulders with time are pulled forwards as the chest muscles get stronger, bigger and shorter, making the posture more rounded, creating pain and potential pathology.

Why is a rounded posture problematic?

Rounded postures place the shoulder joint in an unbalanced position away from the ideal centred position. This unbalanced position leads to increased compression at the shoulder, resulting in pain and reduced function:

  • Compression of muscles and other structures at the front of the shoulder joint, may cause pain in the neck, and or down the front of the shoulder and side of the arm. Pain is usually worse with overhead activities. If the compression of the tendons continues for long enough, tears of the tendons (rotator cuff) may occur.
  • Rounded postures often lead to neck pain. A large number of muscle that attach to the shoulder also attach to the neck at the other end. If these muscles are affected (lengthened and weakened by the pull of the shoulders) the neck often tends to rest into a head forward ‘chin-poke’ position. This increases the pressure on the neck joints and also other pain sensitive structures around the neck that can cause symptoms (Szeto, 2005).
  • The shoulder’s range of movement is significantly reduced as a result of having less space for the joint to move. (Bullock et al, 2005)

Additional contributing factors leading to rounded shoulders

Modern Lifestyles

Think about all your daily activities; washing your face and hair, driving, sitting at the computer. People are becoming chair-shaped, and this keeps the shoulder in a rounded position.

Pain Response

Your body’s response to pain is another factor. When you have neck and shoulder pain we often adapt a rounded posture. This initially is good protective mechanism to prevent further damage for the first few days post-injury, however in the long term this posture keeps the shoulder in a poor/compressed position and will hinder healing.

How to correct your rounded posture?

As a guide, when looking from a side view your shoulders should be fairly central compared to the trunk, and the head should be central on the shoulders. A ‘plumb line’ from the centre of the ear should fall through the centre of the shoulder.

To get into this position roll your shoulders all the way forwards, then all the way back (your shoulder blades should touch), then find the mid-point between these two position. When you have this, gently tuck your chin in, so that your head is positioned on top of your shoulders.

2 methods to add to your gym routine to prevent over-training

1) Weight-training

If you work the chest 2 x weekly, doing 6-9 sets of 12 repetitions, then do the same amount of work, at the same load and intensity for the opposing muscle groups – the upper back muscles. Most chest exercises involve pushing – therefore to balance this and work the upper back you must include pulling type activity. Some ideas are provided below.

  • Lat pull down
  • 45 degree angle lat-pull down
  • Seated row
  • Bent over row
  • Pull ups
  • Shoulder external rotation

2) Stretching

As well as strengthening (which contracts and thereby shortens muscles), you should ALWAYS stretch all the muscles you have trained (lengthen the shortened muscles ) at the beginning and end of your workout to reduce tightness of these muscles. In this scenario it is therefore strongly recommended to stretch both the pecs and back muscles.
To stretch the pecs try this one: Pec’s: Corner room stretch

  • Hold 30 seconds
  • rest 30 seconds
  • repeat x 3 (4 x daily)

Experiencing neck pain? Click here to find out more about physiotherapy for neck pain relief and how Core Concepts can help.


  1. Brukner and Khan. Sports Medicine
  2. Bullock, M., Foster, N., Wright, C., (2005).
  3.  Manual Therapy 10, 28–37
  4. Kwok Tung Lau, Ka Yuen Cheung, kwok Bun Chan, Man Him Chan, King Yuen Lo, Thomas Tai Wing Chiu (2010). Relationships between sagittal postures of thoracic and cervical spine, presence of neck pain, neck pain severity and disability. Manual Therapy 15 . p457-462
  5. Szeto, G., Straker, L., O’Sullivan, P., (2005). A comparison of symptomatic and asymptomatic office workers performing monotonous keyboard work—2: Neck and shoulder kinematics. Manual Therapy. Vol 10. p 281–291