By Ryan VanNieuwenhuyze
For years, it has been common thought that athletes and lifters of all kinds must stretch before training or competition, not only to improve performance, but for the sake of injury prevention as well. This line of thinking has been espoused by coaches, physicians, surgeons, physical therapists, athletic trainers, and many other qualified professionals. The implementation of static stretching before training has become so pervasive in the athletic and lifting cultures, that it is something that is hardly even questioned. But, should this be the case?
The first thing that needs to be addressed is the notion of “injury prevention.” Unfortunately, you can never truly prevent injuries from happening. Injuries are a consequence of pushing our bodies to their physiological limits in order to become bigger, stronger, and faster, and is the risk that you sign up for when choosing to pursue your fitness and performance goals. What you can do, however, is reduce your relative risk of sustaining an injury. This distinction may seem like simple semantics, but the intention behind preventing and reducing risk of injuries is significant.
In a paper by Witvrouw E 2012, the authors proposed that static stretching may be a way to reduce injury risk in sporting and training activities due to its effects on the physical structure of the musculotendinous unit.
Many sports, especially field sports and weightlifting in which you often “catch the bounce” out of the hole of a clean or squat, involve movements that require high-intensity usage of the stretch-shortening cycle of the musculotendinous units.
During these types of movements, musculotendinous units that are less stiff (i.e. more compliant) are able to have a higher proportion of energy provided by passive tension of the tissues. This is in contrast to musculotendinous units that are more stiff (i.e. less compliant), which must utilize more active muscular work to produce the same amount of energy. The authors contend that since static stretching improves the compliance of musculotendinous units, it reduces total active muscular work required during these types of movements, and therefore reduces injury risk.
However, this line of thinking does not seem to be well supported in the available scientific evidence examining the effect of pre- and/or post-training static stretching on injury risk reduction.
The likely-most comprehensive review on this topic was done by Lauersen in 2014. This was a systematic review and meta-analysis that analyzed the results of 25 different studies that investigated the injury risk reduction potential of four interventions; static stretching, strength training, proprioceptive training, and a mixed modal approach. In all, there were 26,610 participants with 3464 injuries in these various studies. Strength training was found to be highly effective at reducing injury risk, with a risk ratio of 0.315 (0.207-0.480), and was found to reduce injuries to less than 1/3. Both proprioceptive and mixed-modal training were found to be somewhat effective at reducing injury risk, with risk ratios of 0.480 (0.266-0.864) and 0.625 (0.477-0.820) respectively. However, stretching was found to be not useful at reducing injury risk, with a risk ratio of 0.961 (0.836-1.106). This review validated the use of all interventions except static stretching to reduce injury risk.
Next, another systematic review by Thacker SB 2004 reviewed six studies to determine the efficacy of static stretching for injury risk reduction. In this review, the authors found that the pooled odds ratio was 0.93 (0.78-1.11), which again showed that static stretching is not an effective method for reducing injury risk from training or competition.
Based on their data, the authors concluded that were is not enough available evidence to strongly continue, or discontinue, the practice of pre- and/or post-training static stretching. The authors of this review also proposed that a reason why static stretching may not be effective at reducing injury risk is that the dynamic ROM seen in sporting activities is generally greater than what is available with static ROM due to increased tissue elasticity and reciprocal inhibition, making any improvements in ROM gained from static stretching redundant.
The last systematic review we will discuss is by Herbert RD 2002, which reviewed two studies looking at the effects of static stretching on injury risk reduction in US Army recruits from various platoons. This review also found that static stretching was not an effective intervention for reducing injury risk, with a hazard ratio of 0.95 (0.78-1.16). However, it should be noted that since the participants in this study were military recruits, and the results of this review may not be generalized to the general public.
A likely reason why static stretching does not reduce injury risk potential is that most (non-traumatic) injuries in activities like football, soccer, weightlifting, powerlifting, and most other sports happen as a result of either an acute and dramatic overload of a given body region, or a more chronic but lower intensity overload. When the forces that you are placing upon your body exceed your body’s ability to handle those forces, you may experience an injury. Unfortunately, static stretching does little to nothing to improve the ability of your body to handle forces.
This is where resistance training and workload management come into play. Resistance training actively improves your body’s ability to handle various types of forces or stressors, and proper workload management ensures that you are stressing your body enough through training to drive physiological adaptations, without overdosing your training and running the risk of exceeding your tolerance.
All in all, it appears that static stretching is not an effective tool to use in the name of injury risk reduction, with the available data showing no significant benefit, thereby challenging the cultural standards that many of us have dealt with.
With many of us having fitness and performance goals, the next thing that needs to be discussed is the impact of static stretching pre-training on performance during training.
Numerous studies have been done in this area, but one of the most comprehensive and thorough articles is a literature review by Peck in 2014. The authors of this article looked at numerous studies on the impact of stretching on performance, and looked at the effects on strength/power activities, speed/agility activities, and endurance activities. The authors found that static stretching-pre training decreases performance in both strength/power based activities, as well as speed/agility activities. However, they found that it was unclear if pre-training static stretching has any positive or deleterious impact on endurance performance.
However, it should be noted that these performance deficits that result from static stretching can largely be circumvented by performing a more dynamic based warm-up after stretching and before you train.
So, with the evidence that pre- and/or post-training static stretching doesn’t reliably reduce injury risk, coupled with the fact that there are known deleterious effects on subsequent performance, the cultural norm of static stretching in the peri-training window should be seriously reconsidered.
Based on the available evidence, here are some practical guidelines that I follow in my own training, and generally advise to most of the people with whom I treat and coach.
This combination of preparatory activities will elevate core temperature, peripheral tissue temperature and elasticity, and will address the flexibility and mobility demands for those specific movements.
If you have significant range of motion deficits in a specific joint that is impairing your ability to perform the movements and lifts you are going to train, choose one to two joint/tissue specific stretches or mobilizations and perform them in the pre-training window. However, if you do this, then you absolutely should perform a more dynamic warm-up afterwards in order to mitigate the performance decrements that result from static stretching.
Injury risk reduction should be something that is considered by all athletes. Attempting to reduce your risk of sustaining and injury will mean that you stay healthy longer, can train more consistently, and ultimately make better progress. However, the likely most important things to do to reduce your risk of injury is do some form of resistance/strength training (which, if you’re reading this blog, you’re likely already doing), and utilize proper workload management.
In summary, static stretching has shown no significant impact on injury risk reduction, and has known and well-documented deleterious effects on subsequent performance during training and competition. With this knowledge, athletes should be wary about routinely performing static stretching before their training, and coaches should restructure pre-training and competition practices, saving static stretching for athlete-specific cases in which it is warranted.
Witvrouw E, Mahieu N, Danneels L, McNair P. Stretching and injury prevention: an obscure relationship. Sports Med.
Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomized controlled trials. British journal of sports medicine.
Thacker SB, Gilchrist J, Stroup DF, Kimsey CD. The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature. Medicine & Science in Sports & Exercise.
Herbert RD, Gabriel M. Effects of stretching before and after exercising on muscle soreness and risk of injury: a systematic review. BMJ.
Peck E, Chomko G, Gaz DV, Farrell AM. The effects of stretching on performance. Current sports medicine reports.