Static Stretching Reduces Muscle Strength and Force
It is well known that static stretching reduces strength and force.
But what are the reasons behind it? Does it have any effect on performance? Is there any benefit from static stretching before training? And if so, how much and why?
What Are Static Stretches?
The term “static” stretches refers to muscles being stretched without moving them. They are usually performed with the hands held at a 90 degree angle (supinated) or slightly bent (pronated). A person performing static stretches is called the subject. The other participant is referred to as the control. Both participants perform these exercises while lying down on a mat or chair, but they do not move their bodies during the exercise.
How Do Static Stretches Reduce Muscle Strength and Force?
There are two main theories on how static stretching affects muscle strength and force:
1. It Increases Neural Activity of Muscles.
This theory suggests that when the nervous system receives signals to contract a muscle, it activates those fibers more effectively than when no signal is received. If this were true, then static stretching would increase the amount of force that could be produced by a given number of repetitions.
2. It Reduces the Number of Contractile Proteins in Muscle Fibers.
Another theory is that static stretching can reduce the number of contractile proteins within a muscle fiber, and this in turn reduces muscle force production. If this were true, then static stretching would decrease the amount of force that could be produced by a given number of repetitions.
Does Static Stretching Have any Effects on Performance?
Research has shown that static stretching does affect force production. It seems to decrease the force a person can produce with a given number of repetitions by between 5 and 20 percent. Static stretching also affects performance in dynamic exercise like sprinting or weight training. This decrease in force production seems to last for about 30 minutes after a stretching routine.
Static stretching does not significantly affect isometric strength ( i.e. , the maximum amount of force that can be produced by a muscle without it changing length).
Does Stretching Before an Event Increase Performance?
Research has shown that static stretching does not increase performance. In fact, excessively stretching a muscle before it is required to produce force can actually decrease performance. This is most likely because the muscle becomes temporarily weaker and less responsive to the will.
Does Stretching Before an Event Prevent Injuries?
Research has also shown that static stretching does not prevent injuries, and may even cause a few! However, if static stretching is performed it should be done carefully, and the muscle stretched should be fully warmed up before it is stretched intensely. It should also not be held in an overly stretched position for more than 15 seconds. After this period, it can be gently massaged back to its normal length.
How to Stretch a Muscle Safely
There is a way to stretch before training that seems to decrease the negative effects of static stretching while retaining some of the positive effects. This method of stretching is called active isolated stretching (AIS). Here are the steps:
1. Perform an exercise that you would like to be able to do better because your muscles are too tight for you to perform properly (squats, pull-ups, etc.
2. Find a position in which your muscles are stretched (too far) and perform this stretch for 15-30 seconds 3.
Relax the muscle and continually push it slightly further than you have before 4. Hold this stretched position for 10-15 seconds 5. Gently massage the muscle back to its normal length 6. After the massage, repeat steps 2-5
Here are three basic exercises that you can incorporate into your training program. These exercises can be done in the morning, afternoon and evening. However, they should not be performed within an hour before training or competition. It is also best to actively recover from them by complete rest for at least 48 hours as over-stretching can lead to injury. If you are not a beginner, you should hold each stretch for longer than stated here.
Stand with your feet about shoulder width apart Keep your back straight and bend forward at the hips Lay your hands against a wall or other vertical structure (this can also be done against a chair, table or any other stable support) Inhale deeply and then exhale as you push your hips back. Continue pushing your hips back until you feel a slight stretch along the back of your legs Now slowly lower your chin towards your chest, keeping your heels firmly on the ground Hold this position for at least 10 seconds, while breathing deeply Keep your body straight
Sit in a chair that will support your head while keeping it in a straight line with your spine.
Sources & references used in this article:
Acute static stretching reduces lower extremity power in trained children by JR McNeal, WA Sands – Pediatric Exercise Science, 2003 – journals.humankinetics.com
Acute effects of static stretching, proprioceptive neuromuscular facilitation stretching, and maximum voluntary contractions on explosive force production and jumping … by W Young, S Elliott – Research quarterly for exercise and sport, 2001 – Taylor & Francis
Varying amounts of acute static stretching and its effect on vertical jump performance by JW Robbins, BW Scheuermann – The Journal of Strength & …, 2008 – journals.lww.com
An acute bout of static stretching: effects on force and jumping performance by K Power, D Behm, F Cahill, M Carroll… – Medicine & Science in …, 2004 – academia.edu
Acute effects of static stretching on peak torque in women by JT Cramer, TJ Housh, GO Johnson… – … Journal of Strength & …, 2004 – researchgate.net
Acute effects of static and proprioceptive neuromuscular facilitation stretching on muscle strength and power output by SM Marek, JT Cramer, AL Fincher… – Journal of Athletic …, 2005 – ncbi.nlm.nih.gov
Duration of static stretching influences muscle force production in hamstring muscles by Y Ogura, Y Miyahara, H Naito… – Journal of strength …, 2007 – search.proquest.com