Does stretching before exercise have any benefit? Jennifer Trueland
examines the evidence
Philip Coleman retains a lovely vision in his head from his time as a physiotherapy student in Bristol – and the idea has had a big impact on his practice. ‘One of our lecturers told us you never see a cheetah doing static stretches before taking off at high speed to catch its prey – that’s true – and it turns out animals are far more clever than us,’ he laughs. Even just a few years ago, we’d be thinking that cheetah was wrong; it was accepted that a pre-exercise warm-up should include static or passive stretching. The idea was this helped to loosen up the muscles and tendons and prepare the body for what was to come, improving performance, speeding up recovery time and lessening the chance of injury. Several pieces of research have turned this on its head. Now, indeed, the suggestion is that not only is static stretching a waste of time, pre-exercise, it may actually do some harm (see panel: Round up of research). ‘It’s a hot subject,’ says Mr Coleman, who worked as a personal trainer before undertaking his physiotherapy degree, and who now combines both disciplines in the fitness industry. ‘It’s something which is debated in places like Runner’s World magazine, but if you actually look at the research in this area, you’ll find an awful lot of it is mixed up.’
A prop for the psyche?Tim Sharp is a physiotherapy lecturer at Cardiff University and teaches on the MSc sports programme there. He has an interest in stretching, and like Mr Coleman, regrets the lack of conclusive evidence. ‘Looking at some of the research that’s coming out, it’s accepted static stretching before exercise does reduce force – and that will have an impact on performance.’ But he notes the situation is more complex, and has a psychological component. ‘Many people who are used to doing these stretches simply don’t feel psychologically prepared if they don’t do them. Many of the students I lecture in the undergraduate course are good athletes performing at quite a high level in all sorts of sports like running and rugby – they say they can’t imagine not doing it.’ When Mr Sharp was training, static stretching before exercise was the norm. He believes the pendulum started to swing around the turn of the millennium. ‘I worked in the US for a while and when I came back, people said static stretching wasn’t the thing to do any more.’ It was as if, he jokes, all his experience counted for nothing because he wasn’t following the emerging research blindly. Even now, almost a decade on, he isn’t sure of all the answers around the benefits or disadvantages of stretching. ‘It’s difficult to say, partly because we don’t actually understand the mechanisms that underpin stretching,’ he says. ‘So there’s got to be some caution and apprehension about where we go with this. The good thing is the questions are being asked – but we don’t have the answers yet.’
A myriad variablesResearch suffers, he says, because there are so many variables to be taken into account. There’s no conclusive evidence, in his view, that static stretching before or after exercise reduces injury; it probably impairs performance in terms of reducing force – but the psychological aspects have to be balanced with that. Static stretching after exercise may do some good, in that it might reduce the symptoms of delayed onset muscular soreness (the pain that hits you a couple of days after unaccustomed exercise). This summary chimes with research published in June in the British Journal of Sports Medicine. The study found stretching did not provide clinically important or statistically significant reductions in all-injury risk, but it did reduce the risk of experiencing ‘bothersome soreness’. It also reduced the risk of injury to muscles, ligaments and tendons. However, this study did not provide any clarity for Philip Coleman. ‘The trouble is, this research had stretching before and after exercise, so it is not clear what had the slight benefit. I would agree static stretching as part of a cool down may be beneficial – in developing flexibility, for example – so I guess it was this.’
Dynamic stretchesSo what should an athlete – or even a Sunday morning runner – do before setting off? And what should physiotherapists advise their patients? Many physiotherapists are reluctant to give generic advice. Most would suggest, however, that dynamic stretching – where the stretching involves movement – before and after exercise would be the way to go. For a runner, this might involve stretching the hamstring and quadriceps muscles, by, for example, standing balanced (with upper body support) and swinging the leg forwards and backwards, gradually increasing range and speed, but always staying balanced and always staying in control. This, says Tim Sharp, gets the musculoskeletal system ready to accept force, and activates the muscle throughout the range it will experience during the run.
The bespoke approachThe second piece of advice is that the bespoke approach would appear to be best. The warm-up is almost like a theatrical dress rehearsal – with the actor or athlete working up to the main performance by giving an understated version of what is to come. Just as Helen Mirren would not declaim lines from the television drama Prime Suspect when rehearsing the stage play Phedre, runners should warm up with a bit of gentle jogging, which uses the same muscle groups, rather than cycling, for example. Tim Pigott, a keen triathletewho wants to maximise his own performance, as well as that of the sportsmen and women who attend his private practice, is an advocate of the personalised approach. ‘The big problem with stretching is it has to be tailored towards what training you’re doing,’ he says. ‘A gymnast’s needs are different to those of a front-row rugby player.’ Most sports do not require the muscles to go to anything like the lengths of traditional static stretches, so why not work within the expected range of the actual activity? Finally, on top of that is the importance of the right mindset. ‘There’s a big mental element and there’s something to be said for being consistent,’ says Mr Pigott. ‘If you’ve always stretched before exercise, then don’t panic and try and change it – if it works for you, and you don’t get injured, then stick to it. If you keep getting injured, however, you might want to rethink your strategy.’ FL
The elite approachJust as no two athletes are the same – so no two warm-ups should be the same, says James Moore, a senior physiotherapist at the English Institute of Sport, who works with some of the UK’s top track and field performers. ‘The general perception is elite athletes are similar but that’s not the case. Some are inflexible and others have incredibly good range, so their warm-up needs will be different. I know world-class athletes who can’t stretch their hamstrings – their warm-ups have to take that into account.’ Mentioning no names, he said there was one runner, a medallist, who had genuine force, but was not very elastic and was slow to start; another was more ‘springy’ and faster to start, but had less ‘force’. These strengths even each other out on the track: the main issue is making sure each is as fit as he can be. ‘The system has to be as finely tuned as possible – even if you’re 98 per cent fit in the 100 metres you’ll still come in last,’ he says. ‘Being as fit as you can be is the difference between medalling and not medalling.’
Round up of recent researchSamuel et al, ‘Acute effects of static and ballistic stretching on measures of strength and power’, Journal of Strength and Conditioning Research (2008), 22(5):1422 This study from the University of Nevada in Las Vegas reported common stretches used before running (hamstring and quadriceps stretches) can weaken muscles in the legs, thus having a negative impact on performance, and making it more likely the runner will suffer an injury. Jamtvedt et al. ‘A pragmatic randomised trial of stretching before and after physical activity to prevent injury and soreness’, British Journal of Sports Medicine (2009) published online http://bjsm.bmj.com/cgi/content/abstract/bjsm.2009.062232v1 This international study looked at 2,377 adults who regularly participated in physical activity. The stretch group were asked to perform 30-second static stretches of seven lower limb and trunk muscle groups before and after physical activity for 12 weeks, while the control group was asked not to stretch. The authors concluded: ‘Stretching before and after physical activity does not appreciably reduce all-injury risk, but probably reduces the risk of some injuries, and does reduce the risk of bothersome soreness.’ Soligard et al. ‘Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised trial’, BMJ (clinical research ed) (2008), 337:a2469 Researchers in Norway found a 20-minute warm-up consisting of slow and speed running, strength and balance exercises and movements focusing on core stability, hip control and knee alignment resulted in fewer severe injuries in young female footballers. This included ‘active’ stretching. There was, however, no statistical difference in the number of lower leg injuries between the intervention group and the controls, who used their usual traditional (unspecified) warm-up exercises. The authors concluded further studies were needed to determine which components of the programme were key. Hupperets et al. ‘Effect of unsupervised home based proprioceptive training on recurrences of ankle sprain: randomised controlled trial’, BMJ (2009), 339:b2684 Researchers in the Netherlands found a training programme based on a series of balancing exercises performed as part of a warm-up could cut the risk of recurrent ankle sprains by 35 per cent.
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