Static stretching means holding a stretch without moving for 10 seconds or more. Do you perform static stretches as a warm-up before running? If you do, here’s another question: why do you do them? Because you believe they can help reduce risk of injury? Because they can increase performance? Either way, the static stretches that the majority of us were once taught as standard protocol in a warm-up have actually been under scrutiny for quite some time now, and runners are now often being told to avoid them. Should we stop static stretching in our warm up? Are there any benefits, or are they doing harm? Here you’ll find answers to all of these questions and more.
The discussion as to whether we should or shouldn’t be performing static stretches in a pre-run warm-up actually dates back about 15 years. In 1999, a review by Ian Shrier of 138 clinical and sports science articles connected to stretching and injury surprised many people by concluding that stretching before exercise doesn’t lower the risk of local muscle injury. Studies that pursued Shrier’s review began to prove these results, prompting Shrier to suggest that the whole concept of a more “flexible” muscle being less prone to injury was wrong.
This suggestion was based on the following considerations:
- The majority of injuries occur when muscles are lengthening eccentrically within their normal range of motion. For this reason the idea that lengthening them beyond the required demands of an activity can reduce injury made no sense.
- A recently stretched muscle would be less able to absorb force and release it, a system of force production that running (and any explosive movement) depends on a lot.
- Even a short amount of static stretching can cause micro-traumas in the muscles that will result in the masking of pain and a reduction in proprioception (awareness of body position, posture, movement, etc).
In 2004, a review on the impact of stretching on sports injury risk concluded likewise that stretching wasn’t significantly connected to the reduction in total injuries. The review stated that there wasn’t enough evidence to either endorse or discontinue routine stretching before or after workout to prevent injury among either recreational or competitive athletes. In 2010, a USA track and field sponsored clinical trial followed almost 3,000 runners over three months, with one group performing a pre-run stretching routine and others performing no stretching. Of the runners who completed the study, the risk of injury was the same (16%) no matter which group they were in.
Ten years since Shrier’s initial review and the message was pretty clear: there’s no evidence to suggest static stretching before a run provides any protection against injury.
THE IMPACT OF STRETCHING ON PERFORMANCE
Most of the historic studies on the effects of static stretching set out to examine its impact on injury prevention as opposed to running performance, most probably because the researchers were clinicians, not coaches. However, Shrier’s proposals – particularly that a statically stretched muscle would be less able to absorb and release force – do suggest that static stretching could have a negative impact on running performance.
Research on the effect of static stretching on jumping performance has suggested that stretching prior exercise makes athletes jump lower and more slowly, this means with less force. This could affect sprinters coming out of a starting block, but what about endurance runners, whose demand for explosive movement isn’t as high as that of a jumper or a sprinter?
A 2010 study followed 10 distance runners performing two one-hour runs: the first one after a 16-minute static stretching routine (with 30 second holds), and the second without any stretching. In each of the one-hour runs, participants ran the first 30 minutes at a set pace and the last 30 minutes as fast as they could. Results showed that the runners who didn’t stretch expended an average of 5% fewer calories in the first 30 minutes and managed to run 3.4% further in the last 30 minutes.
The results suggested static stretching before an endurance event could lower endurance performance and increase the energy cost of running. The thing that the study didn’t explain was the mechanism behind the reduced performance and increased energy cost. It could have been Shrier’s proposal of a statically stretched muscle being less able to absorb and release force; it may have been the energy storage ability of the tendons as opposed to the muscles; or it may have been an widely popular theory that static stretching inhibits “neuromuscular” communication, i.e. communication between the brain and the muscles.
Last year the impact of static stretching on the nervous system was further highlighted in a study by researchers from the University of Sao Paulo, Brazil. The researchers asked 11 recreational 10k runners, with best times of 35 to 45mins, to run two 3km races. Runners performed the first race after a 20-minute pre-run static stretching routine (stretches again held for 30 seconds) and the second race with no pre-run stretching. The results showed that those who ran after the stretching routine started at a slower pace and felt a higher perceived exertion (greater effort) during the first 800m.
The researchers concluded that the static stretching routine had reduced the ability of the runners to produce explosive force in the acceleration phase of running and had also made it feel harder.
SHOULD YOU STOP PERFORMING STATIC STRETCHES?
The results mentioned above certainly suggest that at best, static stretching has no benefit for runners in terms of reducing injury risk or improving running performance. At worst, it might even decrease your performance a little, though many runners still swear that static stretching helps them and “feels” better (we can never dismiss the psychological benefit of believing something will help you).
If you usually include static stretching in your warm-up, are injury free and satisfied with your performance, then this is great and stick to it. However, if you like to experiment, try gradually reducing the amount of static stretching you perform. Do this gently and slowly because research showed that if you regularly do static stretching as part of your warm-up and suddenly stop, your risk of injury is doubled.
That said, any rapid change for your body opens a window, be it new running shoes, running off-road or hill sprints. If you are a beginner, try to avoid static stretching in your warm up. It may help in sports that require greater range of movement (dance, martial arts, gymnastics, and similar), however as far as the demands of running go, there’s no proof to suggest it’s either necessary or will help you.
WHAT ABOUT DYNAMIC STRETCHING?
Nowadays, many runners are taught to understand the difference between static stretching (holding a stretch for 10 seconds or more), and dynamic stretching (moving in and out of a position for about 10 to 15 times). Dynamic stretching is considered an alternative to static stretching in a warm up, but before we discuss the difference more in detail, let’s make a comment on the nomenclature. The term dynamic stretching is somehow inaccurate. As Shrier suggested 15 years ago, we should get away from this idea that the purpose of a warm-up is to stretch our muscles, to make them longer. This is an old way of thinking because it omits the most important part of the body that needs warming up – the brain.
Modern schools of thought realize that any movement (including running) starts and finishes with the brain. In most cases, it’s the brain that decides how much a muscle shortens or lengthens in a given moment, if indeed it decides to use it all. When you say that your hamstrings are “tight,” a more accurate description would be that your brain and nervous system aren’t prepared to allow your hamstrings to lengthen, rather than a structural tightness of the muscles themselves. The brain and its communication with the muscles warm up with movement, with mobility.
In 2012, the researchers from Florida State University published a follow-up to their 2010 study using the same protocol, but replacing the static stretching with dynamic stretching. The dynamic movements included toe and heel walks, hand walks, side hurdle step overs, walking groiners, walking lunges, and Frankensteins. As with the previous study, the runners were then made to run for 30 minutes at a set pace (65% VO2max for the technical among you), and then as fast as possible for the last 30 minutes. In comparison to the static stretching study, the dynamic stretching had no negative effect on the distance covered in the 30 minute dash. Though the top two performers did manage to increase their performance slightly following the dynamic stretching routine (the best runner running 0.2km further) and the 2 weakest runners (in terms of distance covered) performed a bit worse (the weakest runner running 0.6km less), the overall effect was minimal and it could be concluded that dynamic stretching at best does nothing.
That said, we recommend the majority of runners, especially recreational runners, to include dynamic stretching in their warm-up (adapted to their individual requirements and the demands of the particular session they are about to do) because this will warm up your mind. Neuromuscular fitness, the ability of your brain to communicate and activate muscles while you are running, is something that running by itself doesn’t necessarily enhance. The functioning of your muscles, lungs and heart are all controlled by the brain. Your running form, power, efficiency, economy, stride length, pace, resistance to fatigue – all controlled by the brain.
A warm up isn’t just a preparation of your muscles and connective tissues for the dynamic range of movement. This is a chance to switch your brain on, to ‘wake up’ that essential connection between brain and muscles in preparation for safe, efficient running. It’s a chance to practice some movement patterns that may promote a more efficient running form which in turn could delay the fatigue and pain that has been affecting your performance or increasing the risk of injury.