Is stretching the key to staying limber, or a recipe for disaster?


Ever since the 1980s, conventional wisdom has held that stretching before exercise – leotard and leg warmers optional – is the key to a good workout without injury. The idea goes that extending and then holding targeted muscle groups (hamstring, calves, quads, etc) warms them up and improves flexibility, thereby improving performance and reducing the aforementioned risk of injury.

A few years ago, though, findings emerged that turned this idea on its head. As it turns out, stretching before exercise can actually increase the risk of injury and negatively impact performance.

A 2013 study found that weightlifters were less effective if they stretched beforehand, while another, a meta-analysis (an evaluation of many studies – 104 in this case), found acute negative effects in athletes who stretched before physical exertion.

It seems counter-intuitive, right? So what is really going on?

In a nutshell, stretching does offer significant benefits to well-being but – as with most things in life – it depends entirely on how you do it.

Most of us associate stretching with holding a position that targets and elongates particular muscles: touching your toes (hamstring), holding your foot against your butt (quads), etc. Known as ‘static stretching’, this is where the danger lies.

‘Broadly speaking, there are two types of stretching: static and dynamic,’ says Keryn Duncan-Smith, a registered biokineticist in private practice at the University of Cape Town’s Sports Injuries Centre.

‘Static stretching, as the name suggests, is when we stand still and hold a stretch position for a period of time. Dynamic stretching, on the other hand, involves movement. Think of the rugby/soccer player you see “warming up” alongside the field with movements like lunges, jumps and side-to-side stepping.’

The goal behind static stretching, she says, is to actually increase the length of a muscle. But by holding the stretch for a long period of time, the muscle may lose its explosive power – potentially leading to an injury if employed in a physically demanding way too soon afterwards.

By elongating the muscle, you are actually making it ‘looser’. This means its tension – the spring-like effect or ‘explosive power’ that enables us to run/cycle/swim, etc – is reduced. This can lead to the muscle becoming less effective.

Not only that, but the loosening of the muscle through static stretching can weaken it as well, making the joint less stable and increasing the odds of a misstep or accident that leads to injury.

Dynamic stretching, as the name implies, is active stretching that involves constant movement – not the prolonged ‘holding’ of static stretching.

‘Some examples of this are swinging the arms or rotating the shoulders. Even a slow controlled squat can be used to warm up the muscles around the hips, knees and ankles,’ says strength and conditioning coach Derek Archer, director of education at the Institute of Fitness Professionals in Johannesburg. ‘Dynamic stretching should be rhythmical and controlled.’

Dynamic exercise essentially warms up the muscle, preparing it for more intense exertion, and stretches it a little without compromising it.

‘It takes the joints through their full range of motion in a controlled manner, to make sure that all muscles around the joint are warm and that the synovial fluid in the joint becomes less viscous,’ says Archer.

The goal of dynamic stretching is to loosen and warm up the muscle in a functional way. In other words, in a sport-specific way. It actually improves muscle-power production, making this the ideal kind of stretching to do before exercise. Static stretching, on the other hand, is best performed afterwards.

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‘It’s tempting to think of flexibility simply in terms of whether you can touch your toes, but there is more to it’


According to Duncan-Smith, the latter offers the highest benefit after exertion because the muscles would have shortened and tightened to different degrees, depending on the exercise type, and there are less likely to be negative consequences of decreased muscle explosiveness.

After exercise, hold your stretches for 20 to 30 seconds, and repeat if a particular area still feels tight.

Both Duncan-Smith and Archer maintain that stretching should be tailored to the individual – every person will have different requirements.

‘Stretching tends to be very generalised,’ says Duncan-Smith. ‘We hear things like “runners must stretch their calves”, “basketball players must stretch their hamstrings”, and “men must stretch their glutes”, when, in fact, tight muscle groups are very specific to the athlete.

‘If you want stretching to be effective, have an assessment done by a physiotherapist or biokineticist, and address the problem areas, rather than generalising. Remember that strength and length must go hand in hand; a weak, long muscle is just as much of an injury risk as a short, tight one.’

The kind of stretching discussed above, however, mainly applies to fairly hard-core exercisers – such as athletes – and not the average Joe, for whom walking their dog counts as their daily quota of exercise (albeit a perfectly valid form).

So, does stretching offer any benefits for people who aren’t about to set off on a 15 km run or go mountain biking?

The answer is, unequivocally, yes. Indeed, many.

It certainly cannot offer the same benefits as cardiovascular and/or weight-bearing exercise – which boosts blood flow and heart health, improves the mood and reduces blood pressure, plus a whole range of other benefits. That said, stretching on its own is still an effective counterfoil to the stiffness and discomfort many of us experience from sitting in one position for too long – for example, in front of a computer.

‘It’s tempting to think of flexibility simply in terms of whether you can touch your toes or not, but there’s a whole lot more to it,’ says Archer.

‘Each muscle that crosses a joint has a specific tension, and if it’s too tight, the joint won’t be able to move through its full range of motion. This can occur as a result of things like age and repetitive postures like sitting at a computer or in a car.

‘The sum total of this is that your posture will be negatively affected and your movement efficiency will be compromised.’

Increased tension in the joints also leads to discomfort and even pain. And over time, the effects can become very difficult – perhaps even impossible – to reverse. We’ve all seen hunched backs in the elderly – this is often attributed to poor flexibility.

However, stretching isn’t just a precautionary measure – it also feels good. There is evidence to suggest it might make us happier (there is a reason yoga is often praised for its mood-boosting benefits).

One study showed that, after a yoga class, sufferers of PMS had lower levels of the antidepressant neurosteroid allopregnanolone. Another found that office workers who made time to stretch during their work day reported lower stress levels. And if you needed any more convincing, there’s even evidence that stretching can improve our quality of sleep and, conversely, make us more alert during the day, most likely thanks to improved blood circulation, which increases oxygen flow to muscles.

Of course, exercise does all of these things too, so if you want to reap the benefits twofold, be sure to stretch and exercise regularly.


By Rachel McGregor
Image: Andreas Eiselen/HSMimages