You might have thought that if you stretch out your tight hamstrings regularly they will eventually get longer, suppler and you might be able to touch your toes again … but this isn’t really how it works, so here’s my over-simplified explanation:

Your nervous system plays a large role in determining your “hamstring” flexibility! 

What I mean is that when you bend forwards and you meet resistance or tightness in your “hamstrings”…. it’s really your brain deciding how far it is willing to let you move in this direction.

For example, if your core is weak then your hamstrings will be told by your brain to ‘kick in’ early to compensate for the lack of stability and act as a brake to activity that might overload and injure your back.

By working on core strength and alignment during movements such as bending you reduce the need for the ‘emergency brake’ action of the hamstrings and your brain is more likely to allow you to move further into range.

That’s not all …

Muscles are made up of little units, like links in a chain, called ‘sarcomeres’ which slide into and away from each other.

When the links slide together the muscle gets shorter and when they slide apart the muscle gets longer. Each link has a set ‘sliding’ distance and this won’t increase by stretching.

When you frequent one position habitually (e.g. sitting) your body tries to be helpful by making adaptations in the length of your muscles to make this position more comfortable for you.

Essentially if your daily routine involves sitting at work, driving home and then collapsing on the sofa exhausted… then your hamstrings are in a shortened position for most of the day and your body will efficiently break down the hamstring muscle links that are not in use when you are sitting.

Ergo over time there will be fewer muscle links … your hamstrings become shorter … and you can no longer touch your toes!

So what’s the answer?

Simply stretching your hamstrings once or even twice a day is not enough of a stimulus and within one hour the effect of this kind of stretching is negligible. It would be far more effective simply to stand up and change position for a couple of minutes every hour in addition to stretching intermittently.

It takes a lot of determination to change the length of a shortened muscle, so as always, prevention is much better than cure … change position and move frequently during the day, stretch intermittently with good alignment and strengthen your core muscles!