Stretching or strengthening? Which to choose and why

Confusing working a muscle with stretching a muscle is really common. When you go to the gym or an exercise class, are you strengthening or stretching your muscles? Can you tell the difference? What are the benefits of each? How do you know which will give you the most beneficial effect?

What happens when you work a muscle?

When you ‘work’  or strengthen a muscle, you tighten the muscle fibres, either by shortening the muscle or by holding it in a static contraction. In order to ‘work’ a muscle, there has to be an effort on your part. The brain needs to send messages to the muscle to activate and engage it. This gives a sensation of strength and, if continued, will make the muscle tire and ache, maybe giving a ‘burning’ sensation.

You can also physically feel the muscle harden. Try pulling your abdominal muscles in as hard as you can. Prod across your tummy and feel the muscle harden in a static contraction. Curl your forearm up into a ‘bicep curl’ position and feel the muscle in your upper arm harden and bulge as the fibres contract and shorten.

Why should you strengthen a muscle?

The short answer is to give support and stabilisation to the bony structures of the body. This is especially important for the shoulder girdle, pelvis, and knees.

Strong muscle tone will enable the body to move effectively with less effort. This, in turn, means that the body can move more before becoming tired. Good muscle tone will also increase your metabolism enabling you to burn more calories on a day-to-day basis.

What happens when you stretch a muscle?

When you stretch a muscle, you are trying to lengthen it. To do this, one end of the muscle is stabilised and the other is moved to a long position. In practice, this is hard to achieve, and, frequently, the stabilised end of the muscle ‘cheats’ by subtly moving to protect the tight muscle and prevent it stretching. Stretching usually involves you taking up a position without consciously putting in any muscle activation.

A common example of this is seen when trying to stretch the gluteus (hip) area. To try this, lie on your back, knees bent, feet flat on the floor and spine neutral (relaxed with a natural gap under and below the waist). Put your right foot across the left knee, lift the left foot off the floor to bring your knees towards your chest. This should give a stretch across the gluteus (hip) area, over the butt cheek down the back of the right side. The pelvis end of the muscle is static and the other end has moved.

Now check whether your back changed its position when you lifted your feet off the floor. Ideally, your back will still be neutral. If it has moved to be flat on the floor this will have moved the pelvis end of the muscle, giving your lumbar spine a stretch it doesn’t need and leaving the gluteus area tight. Roll your pelvis to put the gap back and feel how that changes the stretch as the pelvis is put back into a stable position.

Why should you stretch a muscle?

Some muscles need to be stretched as they shorten through daily activities and this leads to muscle imbalance and pain.

Modern lifestyles can cause other muscles to lengthen. Stretching these will not help and could do further damage as they actually need to be shortened by strength exercises. A typical example is curling over a computer screen which lengthens the back and shoulder muscles.

There are frequently muscles that are tight but the body protects that tightness - so although stretching would be beneficial, it is hard to achieve. As an example the gluteals (butt muscles) often tighten around the sciatic nerve giving pain; if this is released the sciatic pain may disappear but it is hard to achieve this as the body perceives the tightness as protecting the lower back.

Try to strengthen the weak muscles within your body. When you stretch, try to ensure that the correct muscle gets the benefit. 

Most people have developed a pattern of weak lengthened muscles which need shortening and strong tight muscles which need lengthening. A postural assessment will identify these so you can work and stretch to correct imbalances whether in a class, at the gym or in everyday life. Most gyms will offer this service with a personal trainer or massage therapist and it is well worth considering if you are serious about getting a well-balanced physique.