To Stretch or not to Stretch: That is the Question
A Review of Evidence Presented for the Everyday Athlete
Liz Tremblay and Jeff Warren
Injury. This word has been feared for generations among athletes of all ages, sizes, and abilities.
Any barrier that prevents you, the athlete, from enjoying physical activity that you love is always
detrimental. Physical exercise improves the way you feel, improves self esteem, and improves health.
Who doesn’t want to look toned, sleek, and attractive? Body image is such an integral part of self
esteem that any hindrance of keeping this image can be devastating. Various factors lead to injury but
since one human body is completely different from the next, it remains difficult to predict when you are
at risk for injury. Strength training for weak muscle groups, warm-up period, cool-down period, proper
nutrition and adequate rest have all been used as common approaches to staying healthy (when
“healthy” is mentioned in this paper, we are referring to being injury-free) (Mackenzie). However, the
particular warm-up method of stretching has never actually been proven to prevent injuries; yet almost
every coach will have their athletes perform a routine of stretching exercises before a workout. The
question arises, is stretching really beneficial; do you stretch or not?
Warm-up Period: time before exercise that gets muscles ready for movement
Cool-down Period: time after exercise that allows muscles to relax and wind down from exercising
Among many athletes, stretching is an integral part of their exercise routine. Athletes stretch
their muscles before exercise because they believe this reduces the risk of injury (Pope, 1999). Athletes
also stretch after exercise to prevent muscle soreness before their next workout but figuring out which
way prevents the largest number of injuries is where questions arise. The potential benefits derived
from flexibility exercise include injury prevention, reduced muscle soreness, skill enhancement, and
muscle relaxation (Amako, 2003). Even though these are valid factors to take into account, there is no
evidence that pre-exercise stretching does, in fact, reduce injury risk (Pope). “Although many athletes
and trainers have recognized an apparent benefit, the evidence in the medical literature remains
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controversial” as to whether stretching prevents injury (Amako). What are we to believe? If you type
“stretching before workout” into Google, this difference of opinion is very apparent within the first few
results. Links to websites like “Want a better workout? Don’t stretch before…”, “Experts: Don’t stretch
before exercising-USATODAY.com…”, “The Right Reasons to stretch before exercise…”, and “How to
stretch before a workout for dummies…” confuse anyone who looks at them since there is no direct
answer. What is an athlete to do when the all-knowing Internet does not give a direct answer?
In studies conducted on this subject, there is evidence that supports stretching as part of warmup is effective in decreasing the number of injuries among subjects. Stretching of the hamstring before
an exercise routine reduced the number of lower extremity injuries in infantry trainees by 42% (Hartig,
1999). Another study found that stretching as part of warm-up in football players decreased the number
of lower leg injuries by 51% (Cross, 1999). These large decreases in the number of injuries are significant
in that an individual can keep training for that big race or money can be saved from going to the doctor
or overall lifestyle can be maintained.
Other studies, however, suggest that stretching does not have any influence on the prevention
of injuries. Stretching as part of warm-up before training for army recruits did not prove to provide an
effect on preventing injury because of the small 8% decrease in injuries (Pope, 1998). Another study
found that stretching as part of warm-up did not prevent muscle injury in mice when one leg was
stretched and the other was not (Black, 2002). Do the benefits of stretching really prevent injury or is
the prevention in injury associated with another part of exercise?
Table 1: Unresolved Issue
STUDY
Law and Herbert (2007)
*Hartig and Henderson (1999)
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CONCLUSION
Warm-up is effective, Cool-down is not
-13mm score (out of 100mm) for soreness in
warm-up group
-0mm score (out of 100mm) for soreness in cooldown group
Warm-up is effective
-42% decrease in injury of hamstring muscle
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*Cross et al. (1999)
Warm-up is effective
-51% decrease in injury
*Pope et al. (1998)
Warm-up is not effective
-8% decrease in injury of calf muscles
*Pope et al. (1999)
Warm-up is not effective
-10% decrease in injury (5 stretches for lower
extremity)
*Black et al. (2002)
Warm-up is not effective
-9% decrease in injury
*Verrall et al. (2005)
Warm-up and cool-down is effective
-70% decrease in injury of hamstring muscle
*Amako et al. (2003)
Warm-up and cool-down is effective
-64% decrease in muscle/tendon injuries (7
stretches for lower extremity)
*Weldon et al. (2003)
Inconclusive
-Studies reviewed did not provide enough
evidence to discern either way
Woods (2007)
Warm-up is effective
-Stretching should be implemented 15 min before
exercise
Table 1: This table displays the controversy over whether warming up before exercising decreases the
number of muscle, ligament, and tendon injuries. *Indicates studies that used stretching as their main
form of warm-up
This paper is designed to present the data found on this controversial subject and conclude
whether stretching as part of a warm-up or cool-down or both is effective in decreasing the number of
lower limb injuries in physically active adults. Eight research reports and two research reviews are the
studies included. The studies analyzed in this paper occur from 1998-2007 and consist of durations
ranging from 3 days to 4 years. The subjects analyzed in these studies include army recruits, football
players, recreational runners and walkers, and mice. The subjects for the human studies include adults,
male and female, ages ranging 16-50 year olds all healthy to undergo physical exercise with no previous
injuries. The methods used in the studies include separating the subjects into groups, those receiving
stretching treatment and those not receiving stretching treatment. The type of stretching, warm-up, and
cool-down were restricted to lower limb exercises and stretches, upper limbs were not accounted for.
Injuries recorded from each study included injuries of the muscles, tendons, and ligaments associated
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with the lower limbs. The definition of injury had to be defined as any exercise related incident that
required a visit to the doctor/infirmary.
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