Stretching is a buzz word we hear all around the gym. Athletes and coaches saying: ‘I need to “stretch” more’, ‘I’m not “flexible” enough’,  ‘I am “tight” today’.

But what does this actually mean?

Let’s start at the beginning.

What is stretching?

In its most basic form, stretching is taking a muscle to its end range of motion and holding the elongated state for a period of time.

What are you stretching?

Active structures in the body, think muscles, the nervous system, and to a small degree tendons, have the greatest opportunity for improvements. Passive structures, think bones, ligaments, and joint capsules, typically don’t change much without surgical intervention or through adaptations that take place across many years (as is seen in children).

How long does it take to improve flexibility?

Studies in the last decade have shown regular stretching will improve range of motion over a period of 4-8 weeks due to a combination of mechanical factors (actual muscle properties) and neurological factors (input from the nervous system). More below.

What happens when you stretch?

The improved flexibility from a stretching program is due to:

1) Neurological Changes
2) Mechanical Changes

Neurological changes seen with stretching include a reduction in the sensitivity of the nerves and stretch receptors that transmit signals of “stretch” to the brain, allowing for you to stretch further into a motion. There is an increase in the level of certain chemicals locally that act as natural pain killers within the body.

Mechanical changes right after stretching there is an increase in water content, blood flow, and temperature within the muscle. With a regular stretching program, mechanical changes can include a reduction in the amount of stiffness within the muscle and a recent study even showed an increase in the length of the contractible units within the muscle (called “sarcomeregenesis,” but don’t worry about the technical term, it’s not important). In general, research leans towards the nervous system being the primary driver of changes in range of motion (specifically short term). However, mechanical changes do occur through changes in muscle stiffness and muscle length when appropriate stretching methods are used over an extended period of time.

How long should you stretch?

Static stretching in 30-60 second bouts, 5x per week, for a total of 5 minutes per muscle group per week, to the appropriate limit of discomfort (mild to moderate) is optimal for increasing range of motion. Time spent stretching per week is more important than total time spent stretching per session.

What about foam rolling, massage, and other self-soft tissue tools (lacrosse balls, massage gun, etc)?

The most popular thought process regarding the benefit of these techniques is they affect resting muscle tone, increase blood flow, change the amount of water hydration levels within the muscle, and offer a competitive neurological stimulus for muscle soreness. Generally, the effect is thought to be driven more through neurological mechanisms rather than changes in muscle tissues (especially in the short term).

Specifically, foam rolling and massage guns appears to lead to short term changes in range of motion. However, the effect does not stick around long without following up with stretching.

How long should I foam roll?

10-30 seconds per muscle group, avoiding bony prominences (knee elbow, hip), and not going into painful/intense pressures for long bouts.

A combination of self-myofascial release and consistent targeted static stretching yields the most beneficial gains to changes in flexibility.

Dr. Kaysha Bates DPT is a physical therapist based in Jackson Hole, WY