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, (muscles, the nervous system, and to a small degree tendons), have the greatest opportunity for improvements. Passive structures (bones, ligaments, and joint capsules), typically don’t change much without surgical intervention or through adaptations that take place across many years (as 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?
Flexibility improvements seen from a stretching program are due to:
1) Neurological Changes
2) Mechanical Changes
Neurological changes seen from stretching include a reduction in the sensitivity of the nerves and stretch receptors that transmit signals of “stretch” to the brain. This allows for you to stretch further into a position. There is also an increase in the level of certain chemicals within the body that act as natural pain killers.
Mechanical changes occur right after stretching, when 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. A recent study even showed an increase in the length of the contractible units within the muscle (called “sarcomeregenesis”). In general, research leans towards the nervous system being the primary driver of changes in range of motion (specifically in the 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, at a mild to moderate discomfort level, is optimal for increasing range of motion. Time spent stretching per week is more important than total time spent stretching per session. Frequency > intensity.
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 how 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. However, 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 through neurological mechanisms. However, the effect does not stick around long without consistently following it up with stretching.
How long should I foam roll?
It is best to foam roll for 10-30 seconds per muscle group, avoiding bony prominences (knee, elbow, hip), and not going into painful/intense pressures for long bouts.
In summary: 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