Some say that certain types of stretching can play a critical role in making your muscles bigger, unlocking your body’s capacity to grow and unleashing monstrous muscle growth.
One article I came across claims that stretching has the potential to increase muscle mass by a whopping 318% in just 28 days.
It all sounds too good to be true, mainly because it is.
That’s not to say stretching has no benefits at all where building muscle is concerned. But if you’re expecting to see such rapid gains, chances are you’re going to be more than a little disappointed.
Fascial Stretching and Muscle Growth
So what is fascial stretching? How does it differ from regular stretching? And will it make your muscles grow?
Fascial stretching, which you’ll sometimes see referred to as loaded stretching, extreme stretching or intense stretching, is supposed to target the fascia, which refers to the network of connective tissue that surrounds muscle cells.
The idea is that it “remodels” the muscle fascia, giving the muscle fibers themselves extra space to grow.
Here’s how one trainer puts it:
“Because fascia is so tough, it doesn’t allow the muscle room to expand. It is like stuffing a large pillow into a small pillowcase. The size of the muscle won’t change regardless of how hard you train or how well you eat because the connective tissue around your muscles is constricting the muscles within.
“Imagine you can expand the size of the pillowcase by stretching it. Suddenly, the pillow within has more room and will expand to fill that new space. By stretching your muscles under specific conditions, you can actually stretch your fascia and give your muscles more room to grow.”
How Does Fascial Stretching Differ from Regular Stretching?
The main difference between fascial stretching and regular stretching is in the length and “intensity” of the stretch.
Stretching is normally seen as a relatively relaxing activity. You ease into the stretch until you feel a bit of tension on the target muscle. Then you hold that position for a given length of time, be it 20 seconds, 30 seconds, or whatever.
Fascial stretching is a different story entirely.
Dante Trudel’s DC Training is probably the most popular training system to emphasize stretching as a way to increase muscle mass. With DC Training, 60-90 seconds of extreme stretching is done after working a particular muscle group.
Here’s how Dante describes stretching his chest DC style:
“I drop down into the deepest flye I can for the first 10 seconds or so with my lungs full of air and chest out. Then staying there I arch my back slightly and try to press my sternum upward. This is absolutely excruciating. The rest of the 60 seconds I try to concentrate on dropping my elbows even farther down. The last 15 seconds I’m pretty much shaking like a leaf, I have tears in my eyes and I think about dropping bodybuilding and becoming a tap dancer on Broadway.”
The History of Fascial Stretching for Muscle Growth
The first time I came across the idea was back in the 1980’s, when a guy by the name of John Parrillo claimed that fascial stretching, along with 10,000 calories a day and his MCT supplements, would help you build muscle faster.
In the 1990’s, the now defunct Muscle Media magazine ran an article on the subject of SPIDER stretching (SPIDER was short for Stretching with Pre-Induced Defense by Eccentric Repetitions), which made very similar claims.
Although Hany Rambod’s FST-7 (short for Fascia Stretch Training 7) is based on the idea of fascial stretching, the program itself doesn’t place any special emphasis on extreme stretching.
Rather, Rambod claims that a better approach is to “stretch the muscle from the inside out by volumizing it. This is accomplished by getting the greatest pump possible while training.”
Given that it’s been around so long, you’d think that somebody, somewhere would have produced research to show that it actually works.
While there are studies to show that stretching can accelerate gains in muscle size and strength (which I’ll talk more about in a moment), there’s no evidence to show that it does so by altering the properties of fascia.
In fact, a lot of the advice on fascial stretching comes from people who are simply copying and pasting stuff they’ve seen elsewhere. That’s why so much of it sounds the same, which often creates the false impression that there must be something to it.
Can Stretching Increase Muscle Mass by 318% in 28 Days?
Before we go any further, I want to address the claim that stretching will increase muscle mass by 318% in 28 days, which are based on a 1993 study published in the Journal of Applied Physiology .
The study wasn’t actually done on humans, or even exercising animals. Rather, it involved something called an “avian stretch model.”
Basically, a velcro cuff filled with lead pellets is wrapped around one wing of bird (usually a quail, which is a small bird in the pheasant family) while the opposite wing serves as the control.
The weighted velcro cuff is kept in place for several days (or in some cases, several weeks) and serves to stretch the wing in question. The bird is then killed and muscle mass in the stretched wing is compared to that in the control wing.
There is plenty of research to show that this type of stretching leads to an increase in muscle mass in the stretched wing .
However, there’s a big difference between putting the wing of a bird on constant stretch for 29 days and stretching a muscle group for 60 seconds at the end of a workout.
Using this research to claim that stretching enhances muscle growth by several hundred percent is, at best, a gross exaggeration. At worst, it’s total BS.
Stretching and Muscle Growth: The Science
That’s not to say stretching has no effect on muscle growth, although it’s highly unlikely to do so via expansion of the fascia.
The main stimulus for hypertrophy is mechanical tension, and this tension can be produced by actively contracting your muscles or passive resistance to stretch.
In fact, stretching alone has been shown to stimulate the synthesis of new muscle protein, a key driver of muscle growth, albeit to a far lesser extent than muscular contractions .
What’s more, there are various studies, all done using human subjects, to show that stretching has the potential to make your muscles grow.
Back in the late 1980’s, a team of Norwegian scientists found that stretching leads to an increase in the size of muscle fibers . And I’m not talking about a few percent here or there. Both the fast- and slow-twitch muscle fibers grew by upwards of 70% in just four weeks.
However, when you look more closely at how the research was done, the results aren’t quite as exciting as they first appear.
For one, the subjects taking part in the study were in their sixties, suffering from osteoarthritis, and on the waiting list for a hip replacement. The muscles being stretched were victims of disuse atrophy, and had shrunk because they weren’t being used.
What’s more, the stretching protocol involved 30 seconds of stretching followed by a 10-second rest. This was repeated for a total of 25 minutes, five days a week. That’s a lot of stretching, far more than most people are doing in the gym.
In a more recent study, six weeks of loaded passive stretching of the calves on a leg press machine led to a 5.6% increase in muscle thickness . Each stretch lasted a total of three minutes, and was performed five times a week.
A 5.6% increase in muscle thickness is a lot less than several hundred percent. But it’s still worthwhile, especially in the calves, which often stubbornly resist your best efforts to make them grow.
Problem is, we can’t ascribe the results to stretching alone.
That’s because each stretching session began with a warm-up that involved three minutes of two-legged hops on a soft surface, followed by 15 repetitions of bodyweight calf raises.
The warm-up itself, and not just the stretching, may have made a contribution to the increase in muscle mass. In fact, ultrasound scans show a similar increase in muscle thickness in both the stretched and non-stretched legs.
And not every study shows that stretching leads to an increase in muscle size.
In one trial, Japanese researchers found that four weeks of static stretching (120 seconds per day) had no effect on muscle growth . In another, stretching twice a day (four 30-second stretches repeated twice a day) failed to produce any significant changes in muscle mass .
One last thing: If you want to give fascial stretching a try, be aware of the increased risk for injury.
Loaded stretching, particularly with exercises like flyes or pullovers, isn’t doing your shoulders any favors. And I’m not just talking about the potential for a soft tissue injury. In the shoulder joint, there’s a delicate balance between mobility and stability. The increase in flexibility that accompanies stretching can decrease the stability of the shoulder, leading to problems in an area that’s already notoriously injury prone.
You also run the risk of doing some serious damage if your feet slip off the leg press platform while you’re stretching your calves.
So, what’s the bottom line? Is stretching going to help or hurt muscle growth?
If you’re already lifting weights, any effect that stretching has on muscle growth is going to be a relatively small one. Claims that stretching will explode your muscle growth, or increase muscle mass by several hundred percent in less than a month, are well wide of the mark.
What’s more, given that a lot of intense stretching before you lift weights has the potential to put the brakes on muscle growth, you’re better off leaving it to the end of your workout (or at least once you’ve finished training a particular muscle group), rather than doing it at the start.
Christian Finn is the nation’s leading authority on science-based, joint-friendly ways to build muscle. A former “trainer to the trainers,” he holds a masters degree in exercise science, and has been featured in or contributed to major media on two continents, including the BBC and Sunday Times in the U.K. and Men’s Health and Men’s Fitness in the U.S.