After really fucking exhaustive searching of the literature on this subject, I conclude that there is very little support for it in the literature. The best support is posted below.

on FST-7.com (a site based on working out to stretch the fascia), I've seen Hanny Rimbod claim that "the best bodybuilders have really thin fascia so they grow faster and more." something like that. Anyway, the only support for variation in thickness of fascia comes from a few studies on patients with "compartment syndrome," a painful syndrom in which exercise causes great pain, probably because the fascia is restricting blood flow.

It HAS been reported that muscle on patients with compartment syndrome appear to be restricted by thicker, perhaps less elastic fascia.

However, Hanny is talking out his ass when he says fast gainers have thinner fascia. There is absolutely nothing in the literature to support this.

In fact, it's not even clear if people with compartment syndrome exhibit slow or restricted muscle growth.

That said, the following study looks at the results of fasciotomy (ie, cutting the fascia), which clearly lessens fascial restriction on the muscle, on muscle fiber growth in patients with compartment syndrome 1 year after fasciotomy.

the study finds significant growth of muscle fibers 1 year after fasciotomy (in the tibialis i think). What is notable however, is that patients with compartment syndrome already have larger mean fiber diameter than controls.

This, of course, doesnt really say anything about normal people, and doesnt' say anything about whether fascia actually restrict muscle growth in normal people. In fact, it appears to be believed that the fascia should NOT restrict growth.

One other notable finding is that patients with compartment syndrome appear to have blunted angiogenesis and resultant capillary density.


Scand J Med Sci Sports. 2009 Oct 4. [Epub ahead of print]
Evidence for low muscle capillary supply as a pathogenic factor in chronic compartment syndrome.

Edmundsson D, Toolanen G, Thornell LE, Stål P.
Department of Surgery and Perioperative Science, Division of Orthopedics, Umeå University Hospital, Umeå, Sweden.
There is a paucity of data regarding the pathogenesis of chronic exertional compartment syndrome (CECS), its consequences for the muscles and the effects of treatment with fasciotomy. We analyzed biopsies from the tibialis anterior muscle, from nine patients, obtained during a decompressing fasciotomy and during follow-up 1 year later. Control biopsies were obtained from nine normal subjects. Muscle capillarity, fiber-type composition and fiber area were analyzed with enzyme- and immunohistochemistry and morphometry. At baseline, CECS patients had lower capillary density (273 vs 378 capillaries/mm(2), P=0.008), lower number of capillaries around muscle fibers (4.5 vs 5.7, P=0.004) and lower number of capillaries in relation to the muscle fiber area (1.1 vs 1.5, P=0.01) compared with normal controls. The fiber-type composition and fiber area did not differ, but focal signs of neuromuscular damage were observed in the CECS samples. At 1-year follow-up after fasciotomy, the fiber area and the number of fibers containing developmental myosin heavy chains were increased, but no enhancement of the capillary network was detected. Thus, morphologically, patients with CECS seemed to have reduced microcirculation capacity. Fasciotomy appeared to trigger a regenerative response in the muscle, however, without any increase in the capillary bed.