Discover how marathon runners' experiences shed light on the science of muscle soreness and the crucial role of fascia in recovery and performance.
Dynamic Ultrasound Assessment of Tissue Gliding Dysfunction in Marathon-Induced Muscle Soreness: A Pilot Study
Based on Katayama-Miyazaki et al.
Click here for full unedited research article
If you’ve ever run a marathon (or just pushed a long run a bit too far), you’ve probably met delayed onset muscle soreness (DOMS)—that deep, stiff ache that peaks a day or two after exercise.
Traditionally, DOMS has been blamed mostly on microdamage in muscle fibers and the inflammation that follows. But recent work suggests that this muscle-only view misses a big piece of the story. The deep fascia—the connective tissue that surrounds and links muscles—also appears to play a major role in how soreness develops and how long it lasts.
This pilot study used dynamic ultrasonography (moving ultrasound) to look at something quite specific:
How the tissues under the skin slide over each other (or fail to) before and after a marathon.
The focus: tissue gliding—the smooth relative motion between skin, fascia, and muscle that helps everything move comfortably.
Between the skin, superficial fascia, deep fascia, and muscle, there’s a layer of loose connective tissue rich in hyaluronic acid (HA). Under healthy conditions, this system allows the layers to glide past each other easily, reducing friction during movement.
If the properties of this connective tissue change—becoming thicker, stickier, or more viscous—interlayer movement can be restricted. That’s called tissue gliding dysfunction, and it may:
Increase local stress and strain
Make tissue feel tight, stiff, or painful
Contribute to limited movement and lingering soreness
The idea behind this study: when DOMS shows up after a marathon, does tissue gliding actually change in a measurable way? And does it recover as the soreness fades?
This was a small pilot study, intentionally simple but carefully controlled:
2 healthy, male recreational runners
Young adults with regular aerobic training (~7 hours/week)
Both running their first marathon
The marathon itself was a non-elite, community-based event in rural Japan, with a generous time limit and a focus on participation rather than competition. Both runners completed the race in just over five hours.
To create a sense of what “normal” looks like, the researchers also recruited:
10 healthy volunteers (no recent soreness or heavy resistance training)
Their calf tissue gliding was measured once, under the same conditions, to establish a reference range.
All measurements were taken with the runners lying on their stomachs, with the calf muscle relaxed. The same experienced examiner did all the ultrasound work to keep things consistent.
The team looked at three main things in the calf (gastrocnemius) muscle:
Soreness on palpation (DOMS)
Light pressure was applied at a consistent location on the calf–Achilles junction.
Runners rated soreness on a 0–10 scale (0 = no pain, 10 = worst imaginable pain).
Deep fascia thickness
Using standard ultrasound imaging, the thickness of the deep fascia in the calf was measured.
This gives a snapshot of whether the fascia is swollen or thickened, which can happen after mechanical stress and inflammation.
Tissue gliding dynamics
This is where it gets interesting.
With the ultrasound probe held steady over the calf, the examiner gently pulled the skin about 5 mm in one direction and then let it return—like a small, standardized skin glide.
This was repeated rhythmically, and the motion of:
the skin,
the subcutaneous tissue, and
the muscle layer
was tracked on video and analyzed frame-by-frame.
From those videos, the researchers focused on two things:
How far the tissues actually moved (gliding distance)
How they moved relative to each other (movement pattern)
They described these patterns as:
“Counter phase” – skin/subcutaneous tissue and muscle move in opposite directions, which appears to be typical in healthy, pain-free tissue.
“Shifted phase” – the muscle lags behind the subcutaneous layer, suggesting some resistance or “stickiness” between layers.
The runners were assessed:
Pre-race: 2 days before the marathon
Post-race: daily for five days (D1–D5) at roughly 24-hour intervals
Not surprisingly, both runners followed a classic DOMS pattern:
Before the race: No soreness (score 0)
Days 1–2 after: Soreness peaked in the calf
By Days 3–5: Pain levels dropped substantially and were mild to minimal
Neither runner needed to significantly adjust daily activities or rely heavily on self-care—so this was the typical, “annoying but manageable” kind of DOMS.
Here’s where the fascia and gliding story lines up with the symptoms:
After the marathon, the deep fascia in the calf became thicker, consistent with temporary swelling and connective tissue changes.
At the same time, tissue gliding distance decreased—the tissues didn’t slide as far relative to each other during the skin traction test.
Importantly, those post-race gliding distances dropped below the normal range established by the healthy volunteer group.
As the days passed and soreness decreased, both:
fascia thickness, and
gliding distance
gradually returned toward their pre-race, “normal” values.
So the time course looked like this:
Peak soreness = thickened fascia + reduced gliding
Reduced soreness = fascia and gliding recovering
Beyond the distance, the pattern of motion between layers changed too:
Before the marathon and again from Day 3 onward:
The runners showed a counter-phase pattern—subcutaneous tissue and muscle moving in opposite directions.
This matched what the researchers saw in the healthy volunteer group and was treated as a normal “healthy” pattern.
On Days 1 and 2 after the marathon, when soreness was at its worst:
The pattern shifted into a “shifted phase”:
The muscle layer lagged behind the subcutaneous tissue.
This was interpreted as a sign of gliding dysfunction—like the layers were less free to slide, or “sticking” to each other.
As soreness eased and the fascia began to normalize, the runners returned to the counter-phase pattern.
This suggests a tight connection between what people feel (DOMS) and what the tissues are actually doing mechanically under the skin.
This study is small, but it reinforces a big shift in thinking:
DOMS is not just a muscle fiber problem.
Changes in deep fascia structure and tissue gliding appear to move in lockstep with soreness.
For clinicians, therapists, and coaches, this has a few important implications:
Visualizing tissue behavior
Dynamic ultrasound provides real-time video of how the tissues move.
This can be a powerful education tool—showing patients that their pain might be related to how layers are sliding (or not) over one another.
Informing manual therapy and movement strategies
Many manual therapy techniques and recovery strategies (massage, fascial work, skin traction techniques) already target the skin–fascia–muscle interface.
If we can improve tissue gliding, we might also influence how quickly or comfortably someone recovers from DOMS—though that still needs to be tested directly.
Creating better metrics for recovery
Tissue gliding could become an objective marker of recovery, complementing subjective pain scores.
This could be useful for evaluating different training loads, recovery plans, or hands-on interventions.
After a marathon, the calves don’t just hurt—they also slide differently.
When DOMS peaked, the deep fascia was thicker, tissue gliding was reduced, and the muscle tissue lagged behind the layers above it.
As soreness faded, fascia thickness and gliding distance returned toward normal, and the motion pattern between layers looked “healthy” again.
In short:
DOMS appears to involve a temporary “sticking” of tissues, not just tired muscles.
Understanding and measuring that gliding may help us better explain, monitor, and eventually treat post-exercise soreness.