Getting to the bottom of it – muscle soreness or fascia soreness?

We all know it – getting up the morning after an intensive workout session or hard physical labor can become torture due to pain in the legs or the butt, a typical muscle soreness. What’s a welcomed excuse for couach potaotes can be an annoyance for sport enthusiasts because it requires a few days without training or working on other muscle groups. But where does this pain actually come from? It turned out only recently that the common understanding of muscle soreness was simply false.

Is it muscle soreness…

A few years ago, lactic acid was seen as the main cause for muscle soreness. Heavy muscle work leads to the creation of lactic acid which causes the muscles to overacidify. Lactic acid, however, is far quicker breaken down than the muscle soreness needs to fully come into play. Often times, you can feel the worst muscle soreness two days after your workout. At that point, the lactic acid is all gone. Thus, this hypothesis isn’t sustainable anymore. Nowadays, science represents the hypothesis that it is micro-ruptures, little tears in the muscle fibers, that can result from overloading the musculature. This occurs especially during (too) great excentric loads like slowing movements during a mountain run. In order to speed up regeneration, the healing of the muscle fibers, and to alleviate the pain, moderate movement and warmth (sauna, bath) can help to improve blood circulation. With constant training you can avoid muscle soreness because you strengthen susceptible muscles and tissue structures and get them used to the loads. But you can quickly get muscle soreness again when you include new and intense movements into your workout.

The common knowledge that subsequent stretching after a training session can counteract muscle soreness has been proven to be false. It might be a relic from the time where lactic acid was still seen as the major culprit for muscle soreness. Micro-ruptures in the mucsle fibers can, of course, not be made undone by stretching. You will probably make it even worse.

…or rather fascia soreness?

It is far more likely that the pain of soreness actually comes from the fascia. Fascia is what we used to call connective tissue. There is no consistent definition in the literature. To put it simple, connective tissue is everything that binds and connects. As an example you can see the lumbar-dorsal fascia which (not only) spans over the (lower) back in the picture below: Thanks to recent studies and scientific findings the fascia has steadily increased in popularity for athletes, therapists, and scientists alike since 2010. The desired results of the ongoing studies are increased regeneration and performance as well as releasing problematic areas. Other goals are to activate the positivie effects of the immune system and to get firm skin. The fascia, or connective tissue respectively, encases the muscle belly as well as every muscle cell, muscle fiber, and muscle fascicle. It connects the muscle with the bone and the neighboring muscles. Connective tissue tiles also support bones and nerve fibers and encase nerve cords, bones, and organs. Fascia are groups of cells that work like a slide layer to make everything slide and keep the body flexible. The connective tissue divides the body into numerous shells and chambers and works like a three-dimensional net that stabilizes and gives orientation. Ida Rolf calls it ‘an organ of form’. The current state of science accounts the following functions to fascia:

Function	Explanation
Connective function	Muscles, organs, and skin are connected to the neighboring tissue by fascial structures. A network in your body without start and end. They connect muscles with their neighbor muscles and, thus, connect the whole movement system with the passive locomotor system or with the inner organs.
Protective function	The connective tissue forms a mechanic barrier against intruding foreign bodies and can absorb and distribute forces or outer stresses. Thus, they are also able to absorb energy and to release it explosively.
Defensive function	Inside the connective tissue there are phagocytizing cells. When our immune system is attacked these cells become active. They are also known as scavenger cells.
Informative function	The connective tissue has a deep neuroplexus that works as an information carrier and mediator in the detection of stimuli and their forwarding. Fascia play a major role for proprioception (body perception, where is my body located in space and where are my limbs in relation to each other?) and can react to different types of stimulation with tension or relaxation.
Transport function	In the connective tissue, the arteries are the transport channel over which nutrients are transported to their destination. At the same time, waste products are transported to the venous vascular system or the lymphatic vessels over the connective tissue.

What is important when talking about the fascia soreness are the transport and information functions in general and the lymph vessels in the fascia in particular. The transport function which is kept in motion by muscle movement alone can be affected by tensions in the musculature. As a result of the tensions in the muscle, the substances in the lymph vessels can’t be fully degraded. Thus, the fibrinogen in the lymph vessels is reduced to fibrin. Fibrin is an endogenous ‘glue’ that is supposed to seal wounds. Since there are no wounds, the fibrin will only gum up the surrounding fascia tissue. This adherence can lead to two major problems:

• Mobility and tensile force of the muscle fibers that run through this tissue area can be impaired and reduced.
• Nerve endings that lie in the affected area can be contused which could lead to great pain.

Another reason for the pain of fascia soreness (formerly known as muscle soreness) can be an injury of the fascia itself. Damage to the collagenous fibers of a fascia caused by over-stretching, excessive sportive activity, or false posture can result in inflammation which in turn is signaled by pain. What we can learn from this: The assumption that muscle soreness is caused by lactic acid deposits is outdated. Thus, post-workout stretching will not help you fight muscle soreness. Furthermore, it can even make the already existing micro-ruptures worse. The exact cause for the pain that muscle soreness brings is not yet fully resolved but we have moved to the assumption that the pain rather comes from the fascia than the muscles. Stretching and mobility drills won’t help you fight already rising muscle soreness but it can greatly help you prevent it before you cause it. When you start working on your mobility regularly, you can resolve already existing adherences in the fascia, the connective tissue will become smoother overall, and it will be better prepared to go with your movements during your workouts. Taking precautions is clearly better than aftertreatment! Sportive greetings, Your Jens