Superoxide Dismutase (SOD) is an enzyme that plays a critical role in the body's defense against oxidative stress by catalyzing the conversion of superoxide radicals into oxygen and hydrogen peroxide. In the context of the muscular system, oxidative stress is a well-known contributing factor to muscle fatigue, damage, and impaired recovery following intensive exercise or injury.

There is some scientific evidence suggesting that SOD, particularly when administered as an oral supplement, may reduce markers of oxidative stress in muscle tissue and improve recovery. Several animal studies and a handful of small human clinical trials have examined SOD supplementation in relation to exercise-induced muscle damage. Results are mixed but some studies indicate a reduction in oxidative damage and inflammation, along with improved muscle function post-exercise. However, oral bioavailability of SOD is a challenge; the enzyme is typically broken down by digestive enzymes before it can exert systemic effects, though some formulations claim to overcome this via encapsulation or derivatization.

Overall, while there is a plausible scientific rationale and some preliminary evidence for SOD's supportive role in muscle health, the quality and quantity of human data are limited. Therefore, the evidence rating is moderate to low (2 out of 5). Further large, well-designed clinical trials are required to substantiate its efficacy for muscle support.