Flexibility Myth Busting

Thoughts... Welcome to our whistle stop tour of flexibility.

What does someone actually mean when they say they want longer muscles?

Is that possible?

Do you know exactly how muscles can change? And what kinds of training does actually change muscles...?

Hint: doing high volume light reps won’t give you long muscles...

The current blog post by no means exhausts the research it is simply an example of some non-context specific studies and theories surround flexibility. Part 2 will include more training details.

Myth 1: Stretching Makes You More Flexible but you need to do it for ages...

A brief glance at the research and literature means that you can always find a piece of research to confirm your own bias... This is often where slapdash instagram posts come from about training and nutrition in general. So, a small study from 1997 has demonstrated that 30s of stretching for the hamstrings effectively increase range of motion. First thing to notice is that the study mentions theres no benefit of stretching for 60 seconds vs 30 seconds and the effects were only short term. Also a huge take home from this early study shows that stretching more than once per day made no difference either.

So lets bring this information up to date... 23 years is a lot of time in stretching research...

A review conducted in 2011 presented that static stretching in long durations may impair neuromuscular performance. Neuromuscular Performance is something that Dancers need. However, it does make the recommendation that activities that require a large amount of static flexibility should include short duration, low intensity stretches in their warm ups. (No this doesn't mean sit in the splits... This will lower your force production capabilities and place you at greater risk of injury).

Next up, 7 weeks of static stretching after training sessions for 2 x 30s on specific muscle groups is effective for improving flexibility in young male soccer players. Yet the important aspect here is context. Soccer is not heavily reliant on flexibility as a key to performance, unlike Dance despite the prevalence of hamstring injuries. This is more attributed to strength and muscle structure. Yet just a small dose of stretching seems to be effective for increasing ROM over a period of time in this population.

The gold standard of scientific reviews usually come in the form of a Meta-analysis. In 2016, a particular systematic review from Medeiros and colleagues showed that static stretching is effective for increasing hamstring flexibility yet the optimal training methods are still not widely understood.

So what is everyone's problem with stretching?

The issue comes with the mechanism by which we believe stretching helps. Currently there are schools of thought that believe rather than actually changing the muscle length, stretching simply increases your stretch tolerance. So we still aren't making long muscles by stretching. In fact, we are just switching off a possibly vital reflex that tells the brain that body is under threat. Hence the increased tolerance. The danger comes if a Dancer does not increase their strength at their end ROM.

Myth 2: Resistance Training Makes You Less Flexible...

This one, I love. The old chestnut of "if you use weights you'll lose flexibility". Well... if we really think about it... you could have all the flexibility in the world but if you have zero strength you wont lift your leg at all.

A few things we have to assume first of all.

We are a product of what we spend out time doing. Therefore, if we were to stop Dancing and moving and simply perform squats (for example) then you may expect to lose some Dance specific flexibility.

Secondly, consider myth 1 and how muscles are not necessarily increasing in "length" via stretching, the same volume of muscle is simply tolerating being pulled to a greater level of stretch than before.

So can strength training actually add to muscle length in the same way it does to cross-sectional area?

If we address the literature widely we can quickly find a simple study performed on body builders that showed squatting improved... Squatting surprise surprise and there were significant reductions in hamstring flexibility. But wait, this is bodybuilding flexibility isn't important and the population is so far removed from Dance that this may not be relevant as there were no protocols in place to aid hamstring flexibility. So far it doesn't look good for resistance training (Darn it!).

But wait, upon closer inspection it seemed it was just those who were training at 90+% of 1 rep max that have had significant reductions. The group training at a moderate intensity were not significantly impacted. Therefore, maybe it's in the programming and application of strength training or even the type of strength training.

Ribeiro and colleagues conducted a fascinating study in 2017 which appears to not only preserve flexibility after strength training but also increase it.

Agreed this post probably ends with more questions at the end of it but thats where Part 2 is needed to share with you exactly how strength training can enhance flexibility.