Is "Delayed Onset Muscle Soreness" a False Friend? The Potential Implication of the Fascial Connective Tissue in Post-Exercise Discomfort

Abstract

Strenuous and unaccustomed exercise frequently lead to what has been coined "delayed onset muscle soreness" (DOMS). As implied by this term, it has been proposed that the associated pain and stiffness stem from micro-lesions, inflammation, or metabolite accumulation within the skeletal muscle. However, recent research points towards a strong involvement of the connective tissue. First, according to anatomical studies, the deep fascia displays an intimate structural relationship with the underlying skeletal muscle and may therefore be damaged during excessive loading. Second, histological and experimental studies suggest a rich supply of algogenic nociceptors whose stimulation evokes stronger pain responses than muscle irritation. Taken together, the findings support the hypothesis that DOMS originates in the muscle-associated connective tissue rather than in the muscle itself. Sports and fitness professionals designing exercise programs should hence consider fascia-oriented methods and techniques (e.g., foam rolling, collagen supplementation) when aiming to treat or prevent DOMS.

Keywords: DOMS; athletes; eccentric exercise; fascia; pain.

Figure 1

Schematic model of a fascial DOMS-origin. During strenuous exercise (1), morphological damage occurs in the extramuscular connective tissue (2), which stimulates algogenic free nerve endings (3a). At the same time, local inflammation and edema produce local swelling and further increase pain (3b). Original figure created by the authors.

Figure 2

Shear-wave elastography (SWE) of the ventral thigh before (left) and 48 h (right) after lower leg eccentric exercise. In SWE, an acoustic radiation force impulse is used to produce shear waves traveling perpendicularly. Measuring the speed of this horizontal shear wave propagation allows the calculation of mechanical properties. The colored regions of interest indicate the tissue’s mechanical stiffness: while blue represents low values, red represents high values. Note the marked stiffness increase in and near the deep fascia over the muscle (small circles). The scans used for this figure were acquired in the authors’ laboratory.