Could whole-body cryotherapy (below −100°C) improve muscle recovery from muscle damage?

Muscle performance might be temporarily impaired by high-intensity exercise performed during a competition or training session. The attenuation in muscular strength may be transitory, lasting minutes, hours, or several days following training or competition (Barnett, 2006). Longer-lasting impairment in muscle strength accompanied by a reduction in range of motion, an increase in muscle proteins in the blood, an inflammatory response, muscle swelling, and delayed onset muscle soreness is referred to as exercise induced muscle damage (EIMD) (Clarkson and Hubal, 2002; Barnett, 2006; Paulsen et al., 2012). Different modalities have been used to improve recovery from a damaging bout of exercise (Barnett, 2006). Among the most common treatment approaches used to reestablish muscular function are active recovery, compression garments, massage, stretching, anti-inflammatory drugs, and cryotherapy (Cheung et al., 2003; Barnett, 2006; Bishop et al., 2008). A relatively novel modality of cryotherapy is whole-body cryotherapy (WBC), which consists of brief exposure (2–3 min) to extremely cold air (−100 to −195◦C) in a temperaturecontrolled chamber or cryocabin (Banfi et al., 2010; Hausswirth et al., 2011; Fonda and Sarabon, 2013). Sessions of partial-body cryotherapy (PBC), in which the head is not exposed to cold, has also been used as a similar modality of WBC (Hausswirth et al., 2013). According to Hausswirth et al. (2013), WBC and PBC session decreased skin temperature, however, WBC induced a greater decrease compared to PBC. In addition, the tympanic temperature was reduced only after the WBC session. Moreover, parasympathetic tone stimulation was greater following the WBC session. Although WBC has been used since the end of the 1970s in the treatment of rheumatic diseases (KsiezopolskaPietrzak, 2000; Metzger et al., 2000; Rymaszewska et al., 2003), it has only recently been used with the purpose of hastening recovery from muscle damage by decreasing the inflammatory process linked to EIMD (Banfi et al., 2010). A logic model proposed by Costello et al. (2013) consisted of the physiological, neuromuscular, and perceptual effects following exposure to WBC which may interact to increase performance. However, a mechanistic model for how WBC may improve symptoms related to EIMD has to this point not been provided (Costello et al., 2013). Thus, the purpose of this manuscript was to briefly address a possible mechanism related to improved recovery from muscle damage by WBC.