Stretching
While it is a common belief that runners should stretch, the evidence refutes this. With the notable exception of the hamstrings, stretching does not reduce injury risk. Furthermore, flexibility in certain areas is linked to reduced Running Economy.
Contents
1 Claimed Benefits of Stretching
Stretching is claimed to reduce injury, reduce post-exercise muscle soreness and improve performance[1].
1.1 Injury Reduction
Running does not require the flexibility of sports like gymnastics, and generally stretching does not reduce injuries. The only exception seems to be the hamstrings, which are stretched as part of running.
A 1999 meta-study[2] reviewed the research at the time and concluded "stretching before exercise does not reduce the risk of injury". A 2005 meta-study [3] also showed no evidence to support stretching to reduce injury. A 12 week study of 1,538 army recruits[4] showed that stretching 6 different lower leg muscles as part of pre-exercise training did not meaningfully reduce the risk of injury. A study of 10K entrants[5] showed that stretching is correlated to injury, but this may be due to injured runners being more likely to stretch. However, a study[6] of 298 (150 intervention, 148 control) Military recruits showed that hamstring stretches reduced the risk of lower limb injury as well as increasing hamstring flexibility.
1.2 Post-Exercise Muscle Soreness
The 2005 meta-study [3] showed a slight, but not statistically significant reduction in muscle soreness. A study[7] on stretching and eccentric exercise showed no reduction in Delayed Onset Muscle Soreness.
1.3 Performance
A study[8] of 19 sub-elite runners showed that 47% of the differences in Running Economy were related to calf and external hip rotation flexibility, with greater flexibility being linked to lower Running Economy. A study[9] of 34 international level runners showed that flexibility in ‘sit and reach’ test was linked to a lower Running Economy. However, a 10 week study[10] of 32 college students did not find that regular stretching actually reduced Running Economy. It has also been shown[11] that stretching reduces the power of muscles, especially static stretching.
2 How to stretch
A study[12] of different types of hamstring stretch showed that static ‘stretch and hold’ stretch to be the most effective. Holding a static stretch for 30 seconds has shown[13] to be the most effective period. It is generally recommended (but not proven) that muscles should be warmed up before stretching, so stretching should be performed after an initial warm up, or after running.
3 References
- ↑ The Lore of Running, page 775
- ↑ Stretching before exercise does not reduce the risk of local muscle injury: a critical review of the clinical and basic science literature http://www.ncbi.nlm.nih.gov/pubmed/10593217
- ↑ 3.0 3.1 Stretching Before and After Exercise: Effect on Muscle Soreness and Injury Risk http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1250267/
- ↑ A randomized trial of preexercise stretching for prevention of lower-limb injury http://www.tothemaxfit.com/articles/pdf/PreexerPreventInjury.pdf
- ↑ Injuries to runners: A study of entrants to a 10,000 meter race http://ajs.sagepub.com/content/14/2/151.short
- ↑ Increasing Hamstring Flexibility Decreases Lower Extremity Overuse Injuries in Military Basic Trainees http://ajs.sagepub.com/content/27/2/173.short
- ↑ The effects of preexercise stretching on muscular soreness, tenderness and force loss following heavy eccentric exercise http://www3.interscience.wiley.com/journal/119076815/abstract
- ↑ The association between flexibility and running economy in sub-elite male distance runners http://www.ncbi.nlm.nih.gov/pubmed/8784761
- ↑ Running economy is negatively related to sit-and-reach test performance in international-standard distance runners. http://www.ncbi.nlm.nih.gov/pubmed/11774065
- ↑ Chronic stretching and running economy http://www3.interscience.wiley.com/journal/119021773/abstract?CRETRY=1&SRETRY=0
- ↑ Acute Effects of Static and Ballistic Stretching on Measures of Strength and Power http://journals.lww.com/nsca-jscr/Abstract/2008/09000/Acute_Effects_of_Static_and_Ballistic_Stretching.6.aspx
- ↑ The Effectiveness of 3 Stretching Techniques on Hamstring Flexibility Using Consistent Stretching Parameters http://journals.lww.com/nsca-jscr/Abstract/2005/02000/The_Effectiveness_of_3Stretching_Techniques_on.6.aspx
- ↑ The Effect of Time on Static Stretch on the Flexibility of the Hamstring Muscles http://www.physicaltherapyjournal.com/cgi/content/abstract/74/9/845