## 4 Health
### Physical Rehabilitation with Pelotherapy  
As previously mentioned, pelotherapy consists of the local or generalized application of thermal mud, the peloids. The therapeutic interest of peloids, in the natural state or after maturation, is due to the use of the thermal effect (\"Unspecific effects\"), with temperatures that in general baths range from 37 \({}^{\circ}\)C to 38 \({}^{\circ}\)C and in poultices up to 45 \({}^{\circ}\)C, as well as \"crenotherapeutic\" effects, depending on their physical-chemical composition (\"Specific effects\") [2]. [PERSON], 2011, states that the choice of silica and sulfur-rich peloids for treatments in dermatology, cosmetics and complementary therapies for rheumatic and musculoskeletal diseases are advantageous due to their scaling actions (silica and sulfur), buffering (colloidal silica), antiseptic (sulfur) and anti-inflammatory (sulfuric waters) actions. Heat, from 47 \({}^{\circ}\)C to 50 \({}^{\circ}\)C, plays a fundamental role in the beneficial effects of pelotherapy since it reduces muscle contraction and provides relaxation associated with pain relief [43] Therapeutic action through the effect of heat provides numerous reactions, such as vasodilation, sweating, cardiac and respiratory stimulation, and may be related toanti-inflammatory therapeutic effect or the cationic exchange between the mud and the skin [2; 12]. In scientific literature, several studies have contributed to support the beneficial effects of peloids in treating pain, improving functional capacity and quality of life. The mechanism by which immersion in thermal water or the application of mud cataplasms relieves pain in rheumatic patients is not yet fully understood. The distinction can be made between common, non-specific mechanisms (hydrotherapeutic) and simple baths in warm and specific water (hydromineral and crenotherapeutic) that depends on the physical and chemical properties of the water used, the latter being difficult to identify and evaluate. Within the scope of pelotherapy, clinical studies have been carried out to assess the therapeutic effect of the use of clays in patients with rheumatic and musculoskeletal disorders. Most of these studies compare clinical results considering parameters such as the perception of pain, functional capacity, the severity of the disease and medicine intake [43]. Some biochemical evidence relates pelotherapy to increased plasma on \(\beta\)-endorphin levels and secretions of corticotropin, cortisol, growth hormone and prolactin. Recent studies have shown that pelotherapy induces a reduction in circulating levels of prostaglandin E2 (PGE2), leukotrienes B4 (LTB4), interleukin-1\(\beta\) (IL-1\(\beta\)) and the tumor necrosis factor-\(\alpha\) (TNF-\(\alpha\)), important mediators of inflammation and pain [4]. Other studies also demonstrate that pelotherapy decreases inflammatory index and has a positive effect on antioxidant status markers and increased type 1 insulin growth factor [6; 44]. Some of these scientific studies have shown changes in the mechanisms of enzymatic and molecular action after the application of pelotherapy. They have also shown results in chondrocyte metabolism, producing a protective effect on joint carilages after a pelotherapy treatment cycle, as well as influencing antioxidant reactions, inhibiting free radicals. Numerous studies relate the effectiveness of using pelotherapy for knee osteoarthritis and fibromyalgia by improving pain perception, functional capacity, or quality of life. Some of these studies compare pelotherapy with pharmacological treatments and physical rehabilitation techniques, showing greater efficacy in pelotherapy [43; 45]. A clinical study carried out with 24 patients with spondylosis associated with inflammatory bowel diseases ([PERSON]'s disease and ulcerative colitis), over a period of two weeks, showed a reduction in the biochemical indices associated with spondylosis, at the end of a cycle of 12 mud treatments and 12 thermal baths.