Recent years have been hard on traditional sports practices – research has challenged the role of stretching, core stability and footwear choice. Some approaches that have been ingrained in sport for many years are now coming under close scrutiny and one such approach is the use of a 'warm up' prior to sport. I hear many runners guiltily confess, “I never warm up!” but the question is, do they need to and will it reduce risk of injury?…
Fields et al. (2010) examined injury prevention strategies in running and concluded,
“While studies of strength, biomechanics, stretching, warm-up, nutrition, shoes, and psychological factors all raise intriguing questions about both the etiology and the prevention of running injuries, strong evidence that modifying any of these will prevent running injury requires further research”
With regards to warm up specifically, they reported,
“The literature at this point simply does not have enough high-quality research to determine whether warm-up helps prevent running injury”
With questions over the value of a warm up prior to sport there was a genuine need to study this in more detail. Herman et al. (2012) did just that! They performed a systematic review of literature on the topic to determine whether warm up was an effective strategy for reducing injury risk in sport. They adopted a fairly practical approach by including only research that didn't require the use of additional equipment. Considering most people don't have a wobbleboard or ankle disc in the cupboard this is a very sensible idea!
Herman et al. (2012) found just 9 studies that met their inclusion criteria. Unfortunately none of these were on runners and included a small age range of just 13 to 26 years old. The application of their findings to runners of varying age and ability may be somewhat limited.
Source Herman et al. (2012) – freely available online
They concluded that, “effective implementation of practical neuromuscular warm-up strategies can reduce lower extremity injury incidence“.
Their review highlighted several areas that may provide some general guidance on injury prevention using warm up strategies;
- Warm up should include stretching, strengthening and balance exercises, sports-specific agility drills and landing techniques
- This strategy needs to be maintained for at least 3 months
- The warm up needs to be incorporated in all training sessions to be effective
The specifics of exactly what to do during your warm up are not detailed in the Herman et al. paper however one strategy, from Soligard et al (2008), appeared to be effective for preventing a variety of injuries;
“Specifically 'The 11+' reduced overall and overuse lower limb injuries and knee injuries in young amateur female football players“
I've written that last bit slightly smaller in the hope that you won't notice it! But hey, I've pointed it out now so we can't ignore the obvious limitation. Are you a young, Norwegian, female footballer? If not this may not be that applicable to you!
Source Soligard et al. (2008) – freely available online.
That said, again there may be some general guidance we can gain and the exercises used in their warm up make sense, at least theoretically, even if there is a lack of evidence proving their effectiveness for runners.
Soligard et al. encouraged control of impact activities which can be very beneficial to runners;
It appears that warm up has a role in reducing injury risk although that role may be a small one. This is illustrated by the stats from the Herman paper. The 'number needed to treat' ranged from 18 to 729, depending on the strategy used and the injury involved. What this means is that, even in the best case scenario, you'd need 18 participants using a warm up strategy to prevent 1 injury.
These findings makes sense – no warm up technique will allow you to run huge distances or make rapid changes to your training without injury. How much you run and how quickly you increase it are more likely contributors. In a recent study by Neilsen et al. (2013) all runners that picked up an injury had a large increase in training in the week prior to their injury. I think it's unlikely an extensive warm up would have prevented this. Warm up might prepare us for exercise but it can't make us bullet proof!
When it comes to choosing your warm technique it's likely to be most beneficial when based on individual circumstances. Your Physio or running coach should be able to design a technique for you that will help to address areas of stiffness or weakness and prepare your body for the specific demand of your sport. There are some approaches designed to cover most areas, such as these from UKA coach, Dan Pfaff;
- Part 1 – includes sprint drills, basic plyometrics and flexibility
- Part 2 – focuses more on dynamic, multi-directional flexibility
Traditionally static stretches have been used as part of the warm up but recent research has suggested these may be detrimental to performance. @AdamMeakins discusses this expertly in his article on stretching. He points to research by Simic et al. (2012) which suggests that using static stretching as the sole activity during a warm up should be generally avoided, while research by Behm et al. (2011) found dynamic stretching did not negatively affect performance. These findings seem to be mirrored in other studies which fairly consistently report reduced muscle strength and performance following static but not during dynamic stretches.
My thoughts on this are that muscle needs some tightness to function well during running. Tight tissue can function almost like a coiled spring, providing elastic recoil to help propel us forward. If static stretching is detrimental to this process it may be best avoided. That said, there is always a balance. If a tight tissue is causing pain and this is relieved by stretching this is likely to help performance, and make running much more enjoyable!
Limitations of the research
Injury prevention is a challenging area to study. So many factors are involved that identifying the impact of individual contributors, such as warm up, can be very difficult. Large numbers of participants are required and multiple other factors need to be controlled. The strategy needs to be applied over a long period of time, and participants need to be compliant and consistent, not only with the warm up but with reporting injury. All the articles examined in the systematic review by Herman et al. had methodological limitations, such as lack of adequate blinding, small sample sized and inadequate randomisation procedures. Of course the lack of studies specific to runners is an issue, my understanding is that they weren't any of sufficient quality to meet the inclusion and exclusion criteria.
Studies that are specific to runners haven't shown beneficial effects of warm up on injury prevention. Although dated somewhat dated now, the work of Walter et al. (1989) studied 1680 runners and found warm up didn't appear to be associated with injury risk. It should be noted though that this was a large cohort study examining multiple factors and their relationship with injury, rather than evaluating the specific effects of a warm up strategy. In addition van Mechelen et al. (1993) examined warm up in runners but compared 2 approaches, one including stretches and one without. They found a very slightly lower injury risk in the group that didn't stretch (23 injuries compared to 26). However they didn't compare warm up with 'no warm up' and so conclusions on the effect of warm up on injury risk can't be made.
Closing thoughts: clearly more research into the benefits of warm up for runners and exactly what it should include are required. There is evidence that it can have some effect on injury risk and this may be enough to convince people to continue with warm up as a regular part of their running preparation. On a practical level I would recommend sub maximal aerobic exercise, followed by dynamic stretching and sport specific activities based on individual needs. Using the first mile as a slow, 'warm up' mile can also be useful. This approach may reduce injury risk and help performance and will, in many cases, lead to a more comfortable, enjoyable run!