Lifting Weights Can Increase Flexibility Similar to Stretching

Caveats apply, but this is good news for my fellow meatheads

4 min read
By: Dylan Dacosta

I hate stretching. This is likely because I’m not naturally that flexible and we sapiens tend to enjoy doing what we’re good at. Thankfully, some research has shown that what we know as static stretching doesn’t seem mandatory to increase your range of motion. 

Does this mean stretching is useless? Or that all you need to do is lift in order to increase your range of motion?

First answer: Of course not. 

Second answer: Of course not again. But strength training is one of several effective ways to increase your range of motion. 

Study Reviewed

A new meta-analysis was recently published on the topic (1). Here are some details below:

• Studies separately compared resistance training with controls, stretching or a combo of resistance training and stretching on range of motion outcomes. 

• Fifty-five studies with 2756 subjects with an average age of 23.9 (standard deviation of 6.3) and an age range of 8–78 made up the sample. 

• Joints tested for range of motion were the elbow, hips, knee, shoulder and trunk. 

• Resistance training exercises included bodyweight, free weights, machines, pilates and resistance bands. 

Findings

The overall findings were favourable for the meatheads (myself included). No difference was observed between the resistance training and stretching groups on range of motion. The effect size was very trivially in favour of stretching at 0.08. This was not significant or even meaningful. Compared to controls, resistance training was significantly greater for increasing range of motion with a moderate effect size of 0.72. Untrained & sedentary folks saw the greatest increase of ROM with a large effect size of 1.04, while the trained/active folks saw a small effect size of 0.43 (I know it says small, but a 0.43 effect size here is still pretty meaningful). Free weights, bands, machines and pilates all saw increases in range of motion but bodyweight exercises did not. 

Applications

This doesn’t mean you can just exclusively lift and expect to become a mobile yogi. Caveats apply and not all resistance training is created equal in terms of impacting your range of motion. One reason bodyweight exercises didn’t have an impact here is because of some of the typical bodyweight exercises we use. Push-ups come to mind here. In no way is it going to increase the range of motion for your shoulders. Your chest hits the floor before you get into a deep stretch. 

Alternatively, the deep pec fly would stretch your chest and shoulders much more. The key here is that for whatever strength exercise you’re doing if you want it to increase your overall range of motion, you should train in a deep and stretched position. 

Example: The Romanian Deadlift. 

This exercise is fantastic for training your hip extensors, especially your hamstrings, in a deep position. You will feel a huge stretch in your hamstrings when doing this exercise. Alternatively, training your hamstrings on a lying leg curl wouldn’t have the same effect. 

Both of these exercises are great for training your hamstrings. Only one will likely have an impact on your hamstrings' range of motion though. And this would be the exercise that trains them in a stretched position, the Romanian deadlift. 

Strength training is simply loading a joint through a range of motion. Stretching is simply putting a joint/muscle in a stretched position and holding it. This makes strength training in deep ranges of motion a form of stretching. This is why it makes sense that when you do this, you may see similar gains in range of motion than if you held a stretch. 

Conclusions

• New data suggests that strength training can lead to similar increases in range of motion than stretching can. 

• This will only apply to strength training that is done in a stretched range of motion. Think deep squats, Romanian deadlifts and pec flys for example. 

• Stretching is still awesome for improving flexibility. This simply adds more tools to your toolbox if you’re aiming to increase flexibility. 

Cheers,
Coach Dylan 🍻

References:

1. Resistance Training Induces Improvements in Range of Motion: A Systematic Review and Meta-Analysis
   https://link.springer.com/article/10.1007/s40279-022-01804-x