About ten years ago when I was in lower school, I was always told to stretch before I exercise – do static stretching more importantly. It was the norm and it was what we were taught to do before playing sport as it reduced the risk of injury.

Well, it appears that knowledge may be old school and could, in fact, have the adverse effect. Now it’s don’t do static stretching before exercise and only do dynamic stretches (active exercise contractions involving movement) rather than staying in a fixed position for over 20 seconds.

Static Stretching

By stretching a muscle, you are lengthening its muscle fibres. This can result in a loss of function due to a reduction in power. Studies now have shown that stretching the hamstrings (one of the most frequently injured muscles) does not make them less stiff.

A study by Simic and other authors found that pre-exercise stretching reduced muscular strength. After using 104 articles from which they were able to extract data, they concluded the following:

  • Short-term static stretching causes a significant decrease in muscular strength (-5.4%) and explosive muscular performance (-2.0%).
  • It decreases muscle power (-1.9%) although this finding was not considered statistically significant.
  • The shorter the duration of the stretch, the less negative effects on explosive muscular performance (provided the duration of the stretch remains under 45 seconds).
  • Decreases in muscle strength and explosive muscular performance are linked to subjects’ age, gender and training status (training or not training).

Another study using moderately trained men as subjects’ found:

  • A decrease in 1 rep max barbell squat by 8.36%.
  • A decrease in lower body stability by 22.68%.

These effects of stretching themselves can harm running by making your running economy less efficient – in other words, you use more energy to run.

Most confusion about whether to static stretch or not arises with the evidence that static stretching improves flexibility. I cannot disagree with that – static stretching does increase flexibility, but studies don’t consider the cost of static stretching and neither do we. So, let’s go into detail – what happens when you stretch.

More and more modern science is pointing to reasons why static stretching isn’t so great and can actually harm performance. If you look online, you’ll find more and more studies and articles pointing out the link between static stretching and injury.

What Happens When During Static Stretching

When you stretch a muscle it becomes looser, and by that, weaker – this is the reason why it increases the range of motion at a joint. The increased range of motion and flexibility puts more stress on the joint as it is no longer properly supported by the muscle, increasing the risk of injury.

The effects of this type of damage to the leg muscles can affect the gait (running style) of an athlete, potentially making it less efficient. This loss of smooth movement puts stress on the other structures within your body including ligaments, bones, joints and tendons as well as many other muscles. By trying to compensate for these weaknesses and irregular movement, your body ends up using more energy thus hampering your own performance.

A study by Jacob Wilson and his colleagues from Florida State University demonstrated how stretching can cause poor running economy, thus increasing energy consumption during endurance events which in turn decreases performance.

My Thoughts on Static Stretching

Whilst it may feel good to stretch a muscle and lengthen out the muscle fibres, I do wonder how it can possibly help prevent injury. In essence, by not moving, you are allowing your muscle to cool down after you’ve warmed up – what good is that? Static stretching also does not mimic the actions you will be performing in sport, exceptions being dancing, ballet and some martial arts where you need a great range of motion. If you’re stretching before exercise, I would suggest doing dynamic stretches and ones which mimic the movements that you will be doing when you run and can be used to reinforce motor programmes when running such as high knees, A-skips, B-skips, heel flicks. If you choose to do lunges, I would say keep moving during the lunge so you are never stationary for more than 3 seconds.

If you feel it necessary to static stretch, then try to pair it up with dynamic stretching to ensure your muscles are primed for active movement.

If your goal is to boost mobility, do it with dynamic stretches as this will help to elevate heart rate before a run or do static stretches after your run when you’re cooling down.

To warm up, keep it simple – do 15 minutes of light aerobic exercise to prime the muscles, elevate your heart rate, improve the body’s utilisation of oxygen and increase flexibility safely followed by some dynamic stretches or running form drills.

What were you taught about static stretching when you were young? Let me know down below!