Effects of Bathing With Artificial Bath Additive Including Inorganic Salts and Carbon Dioxide on Body Flexibility, Muscle Stiffness and Subjective Feeling of Bathing / 日本温泉気候物理医学会雑誌

ABSTRACT

 The effects of bathing in a solution of artificial bath additive including inorganic salts and carbon dioxide (CO2-bathing 41°C, 10 minutes; the concentration of carbon dioxide was 160-180 ppm, and that of inorganic salts was about 64 ppm) on the cardiovascular system, body flexibility, muscle stiffness and the subjective feeling of bathing were compared with those of no bathing and plain water bathing in the healthy subjects.  The deep body temperature and skin blood flow increased after bathing, and the increases after CO2-bathing were significantly greater than those after plain water bathing. Body flexibility after CO2-bathing was similar to that of no bathing and plain water bathing.  Stiffness of the trapezius muscle was decreased at both 15 min and 30 min after CO2-bathing and plain water bathing, with no change in no bathing. The changes at 15 min after CO2-bathing and plain water bathing were statistically significant. Stiffness in the latissimus dorsi muscle decreased at both 15 min and 30 min after CO2-bathing and plain water bathing, with no change in no bathing. However, only these changes at 15 min and 30 min after CO2-bathing were statistically significant.  A large decrease in the stiffness of the trapezius muscle by its isometric contraction was observed during both CO2-bathing and plain water bathing, and the decrease after CO2-bathing was greater than that after plain water bathing. These changes did not reach statistical significance.  Improvements in subjective feeling of bathing were observed after both plain water bathing and CO2-bathing. Improvements after CO2-bathing in stiffness of muscle, ease of movements and mental relaxation were statistically greater than those after plain water bathing.  Compared with plain water bathing, CO2-bathing showed additional effects on muscle stiffness and subjective feeling of bathing. Further research is needed to confirm the effectiveness of the CO2-bathing alone and combined with isometric movements on muscle stiffness.