Abstract
Massage therapy increases muscle blood flow and heat, relieving pain, improving immune function, and increasing vagal activity. The mechanisms are unclear. Muscles release cytokines and other peptides called myokines. These myokines exert their effects on different tissues and organs in para-, auto-, and endocrine fashion. The aim of this intervention study was to investigate if massage therapy affects circulating myokine levels. A total of 46 healthy, normal-weight subjects (15 men) aged 18-35 were recruited. Forty-five minutes of massage Swedish therapy was applied to the back and hamstrings. Blood samples via cannula were taken at the baseline, during the massage (30 min), end of the massage (45 min), and 30 min and 1 h after the massage. Interleukin 6 (IL-6) and insulin-like growth factor 1 (IGF-1) were measured as surrogate markers by ELISAs. There was a significant increase in IL-6 from 1.09 pg/mL to 1.85 pg/mL over time (Wilks' Lambda Value 0.545, p < 0.000; repeated measures ANOVA). Pair-wise comparisons showed a significant increase after 1 h of massage. No significant increase was observed in IGF-1 levels. The change in myokine levels was not correlated with muscle mass (p = 0.16, 0.74). The increase in IL-6 suggests that there might be anti-inflammatory effects, affecting glucose and lipid metabolism pathways via IL-6 signaling to muscles, fat tissue, and the liver.