Friday, April 14, 2017

Is Static Stretching Necessary?

"We use only 10% of our brains." It was the start of a funny and cheesy pick-up line in Wedding Crashers. It was also widely-accepted as true for decades. Is it true? No, 90% of our brain is not freeloading. Despite lacking any scientific support, many believed this was a fact.


Stretching, specifically static stretching (holding a stretch for 30 or more seconds), has been considered an essential part of exercise for a long time.. This is largely because it reduces soreness and injury risk with exercise and sports...but does it really provide those benefits? Is this an actual fact? Research largely says "no."

Soreness

Delayed Onset Muscle Soreness (DOMS) is the discomfort people feel about 24-72 hours a workout or sport, especially when starting a new activity. Stretching just before or after is commonly said to prevent or reduce DOMS. This is not true, at least based on current research. A review, published in 2006, assessed five studies measuring soreness (1).  People who stretched felt no reduction in soreness at 24, 48, or 72 hours after exercise. Stretching was performed for 5-10 minutes, including holds ranging from 20 seconds to two minutes. Some people stretched before the workout; some stretched afterwards. Regardless, stretching had no effect on post-activity soreness.

Injury Risk

The evidence supporting stretching to reduce injury risk is not encouraging as well (if you're a fan of stretching). A review from 2005 looked at studies focusing on lower body stretching and various lower body injuries (strains, sprains, shin splints, etc.). The result? Stretching did not reduce injury risk.

A study of about 3,000 runners had a similar result when assigning runners to stretching or non-stretching groups for three months (3). In both groups, 16% of people suffered an injury.

A more recent research review did cite a few studies where the static stretching group suffered from fewer injuries...but there was a huge influencing factor: they all performed a warm-up activity of some kind (4). Static stretching by itself does not reduce the risk of injury.

Performance



In regards to soreness or injury risk, stretching is ineffective but not harmful. Stretching could be harmful to your workout or athletic performance. When performed beforehand, static stretching leads to an average reduction of 3-4% in a maximal vertical jump and 1-2% in sprinting speed (4). Obviously these are not huge decreases but could be significant if competing against a person with similar abilities.

When performed before strength training, static stretching reduces the amount of reps a person can lift a weight for (4, 5). Specifically, people perform an average of 8% fewer reps following static stretches (4). One study found rep totals decreased by 9-24%, with the effect increasing with heavier weights (5). This likely happens because stretching reduces the amount of muscle fibers that contract during an exercise.

Is Stretching Useful?

Before answering the question that leads this section, I have one point you should know: I have no "dog in the race." I have no personal vendetta against stretching. I am simply looking for the truth.

Is stretching necessary? Is it useful? In the previous post, I started by saying life is mostly gray, not black and white; a universal rule or answer generally doesn't work. Therefore, my answer to these questions is conditional.

Stretching is useful for increasing joint range of motion, and people in sports requiring large movements (e.g. gymnastics, track and field) should perform static stretching (4). Also, if stretching temporarily reduces pain that you feel, then I think you should stretch. For injury prevention, soreness prevention, or when you are going to strength train, I recommend avoiding static stretching.

References

  1. Herbert, R.D. & Gabriel, M. (2006). Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review. BMJ, 325(7362), 468.
  2. Hart, L. (2005). Effect of stretching on sport injury risk: a review. Clinical Journal of Sport Medicine, 15(2), 113.
  3. Oddi, V. (2010). USATF Announces Results of Pre-run Stretch Study. USATF. Retrieved from http://www.usatf.org/news/view.aspx?DUID=USATF_2010_08_20_12_13_14
  4. McHugh, M.P. & Cosgrave, C.H. (2009). To stretch or not to stretch: the role of stretching in injury prevention and performance. Scandinavian Journal of Medicine & Science in Sports, 20, 169-181.
  5. Nelson, A.G., Kokkonen, J., & Arnall, D.A. (2005). Acute muscle stretching inhibits muscle strength endurance performance. Journal of Strength and Conditioning Research, 19, 338-343.

2 comments:

mrfreddy said...

HI Sean!

You know, I've been avoiding stretching religiously for years, but I think I might start doing some to see if it helps out with my surfing. I don't have a very good pop-up move, which is a problem because you gotta pop up on the board before you can do anything else! I'm hoping some hip opening yoga type stretches can help improve things. We'll see.

Sean Preuss said...

Hi Fritz,

If you feel popping-up might require a large joint range of motion (hips?), I think it's a wise move. I've never surfed, so I have no idea.

I hope you are enjoying life after NYC.

Sean