When you walk into any commercial gym these days, you’ll probably see at least one person using a foam roller. This is understandable because the foam roller has become popular due to the likes of Kelly Starrett, MobilityWOD, and the concept of soft tissue self-mobilization.
Over the last decade, many claims have surrounded the use of self-massage, also known as self-myofascial release (SMR). However, many of those assertions are rooted in anecdotal reports because the research suggests otherwise. Let’s look at four of the top claims.
1. “Breaking Up” Scar Tissue
This is probably the most common rumor you’ll hear. But if you’ve ever participated in a cadaver dissection, you realize that this claim completely misses the mark.
Scar tissue is designed to be self-protective of injuries, and like most intrinsic repair mechanisms, the body builds an extra layer of protection around injured areas. When you dissect an area with scar tissue, it is EXCEPTIONALLY difficult to manipulate, remove, or alter without a scalpel.
For example, when you rupture a tendon or receive a large laceration or incision like from a surgery, scar tissue forms a thickened segment around the affected area. However, this new collagen tissue is laid down rather randomly with varied fiber alignment.
As a result, this change in the tissue’s structure alters its subsequent function. Think back to anatomy and physiology:
Structure predicates function.
If you haven’t studied anatomy and physiology, a simple way to think about this concept is cooking. When you cut bread to make a sandwich, you’d likely use a long serrated knife with teeth. But when deboning and skinning fish, you’d use a filet knife, which is short, thin, and flexible.
In other words, the structure of the tool you use relates to its function. The same is true for the body – certain joints only move certain ways due to the structure of the bones, which in turn affects the function of the joint.
But even before we consider research on foam rolling and scar tissue formation, let’s take a logical and objective view. If scar tissue is delicate enough to be “broken down” and remodeled from pressure applied by a simple foam cylinder, why wouldn’t it completely disintegrate when strength training?
Consider the barbell back squat. The weight of the bar puts immense pressure on the traps at the base of the neck. If someone has scar tissue built up anywhere along the length of the spine or across the shoulders, wouldn’t the pressure from the bar completely destroy the scar tissue?
HINT: It doesn’t.
I’m sure you see what I’m getting at … scar tissue is much more resilient and structurally sound than many realize. While the “foam rolling breaks up scar tissue” argument may sound convincing, you won’t restructure collagen with a simple polypropylene cylinder.
2. Improved Range of Motion
While foam rolling won’t magically break up scar tissue like a skillful scalpel, it can certainly play a role in improving range of motion (ROM), at least for a bit.
Mobility and the perception of “tightness” is a hotly debated topic in physical therapy. But this conversation is much larger than simple joint mechanics.
Any joint’s range of motion is the direct result of central (the brain) and peripherally mediated factors (shape of the joint).
Joints obviously have specific, measurable ranges of motion. We know this due to repeated clinical trials looking at the difference in ROM relative to joint structure. As mentioned above – structure predicates function.
For example, some people’s hip joints tend to flex more than others, while some are much more efficient at rotation. This is largely due to the shape of the hip socket and the angle at which your femur meets your hip.
Unfortunately, we can’t change the shape of our joints without extensive surgery, so if you’re not great at squatting (lots of hip flexion), blame your genetics, not your hips.
However, the basic bony structure of a joint isn’t the only factor driving its function. You see, muscles are dumb. They’re simply the hardware being controlled by the software. The brain is the driver – pain, pleasure, and spatial awareness.
When it comes to changes mediated by foam rolling, our current understanding from the literature tends to suggest that neural mechanisms are responsible for temporary increases in ROM. Since the brain primarily determines muscular activation, this means that the intrinsic perception of “tightness” is primarily dictated by the brain, not the muscle itself.
For example, a 2014 study from the journal of Medicine & Science in Sports & Exercise noted the following:
“The most important findings of the present study were that [foam rolling] FR was beneficial in attenuating muscle soreness while improving vertical jump height, muscle activation, and passive and dynamic [range of motion] ROM in comparison with control. FR negatively affected several evoked contractile properties of the muscle, except for half relaxation time and [electromechanical delay] EMD, indicating that FR benefits are primarily accrued through neural responses and connective tissue.”
Therefore, foam rolling likely does play a role in reducing the user’s subjective perception of tightness. However, this is mainly through neural mechanisms and does not directly influence the total tissue length when at rest.
3. Improved Performance
If you’ve ever been to a high school track meet, you probably encountered endless bouts of static stretching followed by marching and skipping drills. While their coach likely means well, we now know that this pre-exercise procedure actually reduces performance and lowers output.
You may also see some people walk into the gym and immediately perform their first exercise without a warm-up.
So, what’s the alternative?
We know that the body tends to function more efficiently when given adequate time to raise its core temperature. Numerous enzymatic and biochemical factors are temperature-dependent, such as muscle protein synthesis (MPS) and oxygen delivery to working tissues. Not only that, but tissue integrity is heightened in warm(er) conditions.
So if static stretching is somewhat misguided and counterproductive, we need an alternative. This is where foam rolling comes in, along with dynamic warm-up drills, which I will address in a future post.
Foam rolling seems to play a multifaceted role in preparing the body for strenuous activity. We know this from several studies indicating that it does not negatively affect muscular output when used pre-exercise.1) One study even found that foam rolling, coupled with dynamic warm-ups, actually resulted in a positive net increase in strength, speed, power, and agility.2)
While the research is still developing, it would seem that using a foam roller is a better alternative to static stretching prior to exercise due to its influence on core body temperature and the lack of performance degradation. However, you’ll likely find the need to foam roll less as time goes on due to the positive neural and physiological adaptations to the stimulus.
4. Heightened Recovery
While foam rolling may not live up to scar tissue manipulation, there is a large amount of data displaying its positive influence on recovery metrics. For example, numerous studies indicate that foam rolling can reduce the subjective prevalence of delayed onset muscle soreness (DOMS) in well-trained individuals.3)
This is likely due to the compressive effects of foam rolling on the vascular and lymphatic systems. You see, both blood and lymph are needed to remove waste products generated by training and its recovery. If you can’t remove cellular waste, you’ll have a hard time recovering from soreness, limiting your ability to train again.
A 2018 study from Lastova and colleagues also had interesting findings: A 15-minute foam rolling session resulted in noticeable changes in overall vagal tone, which is essentially the balance between two different branches of your nervous system. One is focused on coping with stress (aka “fight or flight”) and the other on relaxation (aka “rest and digest”). The overall balance between input from each system determines how you feel – stressed or relaxed.
The study found that the short bout of self-myofascial release seemed to generate a notable decrease in sympathetic nervous system output and blood pressure for up to 30 minutes after the session ended. They measured this through heart rate variability (HRV).
It has been hypothesized that the increase in pressure applied directly to the skin increases the production of nitric oxide that aids in vasodilation, which increases the size of blood vessels to allow for more blood flow. This lowers blood pressure throughout the system.
While the results are promising, many argue that the effects might be short-lived, meaning they will wear off after 45-60 minutes. That may be true, but this may prove to be a helpful tool for assisting with going to sleep.
We know that sympathetic tone (“fight or flight”) is one of the strongest drivers for wakefulness. Think about how you feel when someone cuts you off in traffic. You immediately wake up despite how tired you are, your heart starts racing, and your body temperature goes up (did you notice that sweat on your neck?). That’s your nervous system helping you cope with the stressor you just encountered.
Therefore, if you have an intervention (foam rolling) that lowers that fight-or-flight input from your nervous system – less adrenaline and more relaxation – why wouldn’t you use it?
Foam Roller: It’s Not What You Think It Is
Here’s a quick breakdown of the research-to-date along with a few takeaways:
- Foam rollers DO seem to enhance individual joint range of motion, even with only short applications, but this enhancement is short-term.
- Using a foam roller DOES seem to enhance recovery by improving blood flow and helping remove cellular waste.
- Foam rollers MAY help to enhance recovery by reducing the input of the sympathetic nervous system – fight or flight – and thus potentially improving sleep.
- Foam rolling before an athletic event or workout DOES NOT reduce performance like static stretching.
- Using a foam roller DOES NOT break up scar tissue.
Foam rolling seems to alter the nervous system, which in turn enhances local muscular function. It will likely continue to be trendy along with massage guns, NormaTec gear, and inversion boots, which we need to continue studying because the current data is inconclusive regarding their effects.
But honestly, we don’t know enough about foam rolling yet. If you like doing it and it makes you feel better, even if it’s only short term, stick it in your warm-up for 5-6 minutes. But please, don’t waste 20-30 minutes foam rolling hoping that you’re physically manipulating tissue. Instead, invest more of that time into training.
|↑1||Halperin, I., Aboodarda, S. J., Button, D. C., Andersen, L. L., & Behm, D. G. (2014). Roller massager improves range of motion of plantar flexor muscles without subsequent decreases in force parameters. International journal of sports physical therapy, 9(1), 92.|
|↑2||Peacock, C.A., Krein, D.D., Silver, T.A., Sanders, G.J., von Carlowitz, K.P.A. (2014). An acute bout of self-myofascial release in the form of foam rolling improves performance testing. International Journal of Exercise Science, 7(3), pp.202-211.|
|↑3||Jay, K., Sundstrup, E., Søndergaard, S. D., Behm, D., Brandt, M., Særvoll, C. A., & Andersen, L. L. (2014). Specific and cross over effects of massage for muscle soreness: randomized controlled trial. International journal of sports physical therapy, 9(1), 82-91.|