Article Review:
Impact of stretching on the
performance and injury risk of long-distance runners
Claire Baxtera, Lars R. Mc
Naughton, Andy Sparks, Lynda Nortona and David Bentleya
Research in Sports Medicine,
25:1, 78-90
Purpose of this article summary:
There are a lot of common beliefs
and a lot of received wisdom floating around about sport, injury, performance,
and rehabilitation. In my experience as a physio I’ve come across many people
who I feel have been misled (willingly or otherwise) through poor- or
mis-information, and this is probably the thing I find most frustrating about
my job. I shared this article a little while back but it is fairly wordy (over
9000 words) and probably not the most easily digested, so I’ve taken the time
to summarise and highlight the areas that I think are of most interest and
importance (in under 800 words).
All references can be found in
the link, so while I won’t reference any of the sources I will only use
the information in the article and not forward my own opinions.
Any suggestions for edits
gratefully received.
Overview:
Stretching has been used by
athletes of all disciplines for preparation, performance enhancement, and injury
prevention for years. However, more recently there has been the suggestion that
this was based on assumptions rather than evidence, and research literature has
been inconclusive.
This study reported on the
current evidence in these areas, primarily in ‘static’ stretching (whereby a
stretched position is held).
In this article, long-distance
refers to 5km and above.
Over the past twenty years there
have been three major viewpoints on stretching and performance, based on
research evidence
- Stretching increases performance
- Stretching makes no difference to performance
- Stretching decreases performance
I’m sure you’ll agree that this
is very helpful.
Stretching & Flexibility:
- It has been reported that 30sec is the optimal time to hold a stretch. Anything beyond that provides no additional advantage
- The optimal number of times a day or week has not been determined
- Acute or chronic stretching?
- Acute refers to the temporary stretch performed immediately before exercise
- Chronic refers to that which is done regularly outside of the warm-up
- Chronic static stretching (over a period of 6 weeks) has been shown to significantly increase flexibility
- There is evidence that suggests elite endurance runners are less flexible than their non-elite counterparts (i.e. us)
- This has been linked to genetics
- The presence of this specific gene has been linked to a greater running economy
- One study found that those with less flexibility had the most economic running style
- Thought to be related to better pelvic stability during foot strike
- Could be related to better elastic energy in tendons and muscles resulting in lower oxygen demand
- HOWEVER, too little flexibility might also increase the risk of injury
- There is thought to be an optimal amount… at present not known!
Performance- Acute Stretching:
- The two main factors in endurance performance are VO2max and running economy
- The majority of the literature available argues that acute stretching causes a decrease in running economy
- This is thought to relate to the “stiffness” of the muscle and tendon, where reduced stiffness means reduced economy
- As a result of this, the debate is now whether stretching decreases running economy of makes no difference
- Acute stretching can actually strain a muscle, increasing its oxygen needs for the next hour
- No studies have found positive effects of acute stretching (i.e. immediately prior to exercise) for distance runners and all showed either a reduction in performance or no change in performance
- In conclusion, the research suggests that acute stretching does is neither useful nor effective in improving performance, and can in fact be detrimental. A low-intensity, progressive run may be best.
Performance- Chronic
Stretching:
- Studies have shown that chronic stretching can increase flexibility without inhibiting economy, but also without improving performance
- No studies have shown an improvement or decline related to chronic stretching
- But remember that others have indicated that lower flexibility is linked with greater economy
- If runners feel the need to include stretching as part of their exercise regime, it’s recommended not to do so immediately before running
- In conclusion, chronic stretching does not appear to have a negative impact on performance. Evidence is limited.
DOMS:
Delayed onset of muscle soreness
(DOMS) is a common occurrence in runners. The specific cause is unknown but is
usually associated with greater eccentric forces (which are significant in
running, especially downhill) or unaccustomed exercise.
- Once study has shown no significant difference DOMS whether stretching or not
- Other studies have had similar findings
- It is recommended that athletes try other methods to reduce DOMS (e.g. ice, heat, massage)
Stretching and Chronic Injury:
- Chronic (long-term) injuries are seen most commonly in long-distance runners
- Most participants are aged 35-50
- One study found 45% of male runners had an injury in a one year period, the most common of which was calf/Achilles
- The majority of studies suggest that stretching has no impact on the risk of chronic injury or overuse injury in endurance runners
- The general findings are applicable to other repetitive-motion endurance events (e.g. cycling and swimming)
- Another study has commented that stretching may be an important tool in maintenance of joint range of motion
In Summary:
- Current research shows no beneficial effects of stretching for endurance runners on performance, injury, or DOMS
- Stretching may be detrimental to performance
- A pre-exercise, sub-maximal warm-up (not involving stretching) may be beneficial
- Research remains limited
- Progressive and planned training are the best way to reduce injury risk and promote recovery, along with other management approaches
