Changes of pain behaviors in mice and relationships between pain behavior thresholds and total running distances in PSL-Runner mice. (A) von Frey test and (B) plantar test were performed in VE (Voluntary exercise for 14 days)-PSL-Runner (closed circles with solid lines, n = 6), FE (Forced exercise for 14 days)-PSL-Runner (closed circles with broken lines, n = 6), VE-PSL-Sedentary (closed triangles with solid lines, n = 6) and FE-PSL-Sedentary (closed triangles with broken lines, n = 6) mice. Mechanical withdrawal thresholds and thermal withdrawal latencies were significantly higher in PSL-Runner mice compared to PSL-Sedentary mice. VE-PSL-Runner vs VE-PSL-Sedentary = †p < 0.05, ††p < 0.01, †††p < 0.001; FE-PSL-Runner vs FE-PSL-Sedentary = *p < 0.05, **p < 0.01, ***p < 0.001. Quantitative data are presented as the mean ± standard error of the mean (SEM). The significance of differences between groups was determined by Student’s t-test. Differences were considered significant at p < 0.05. A significant positive correlation was observed between total running distances during 15 days after PSL surgery and (C) the thresholds of von Frey (R = 0.933, p < 0.001, n = 9) or (D) the latencies of plantar tests (R = 0.818, p < 0.05, n = 8) in PSL-Runner mice. Adapted with permission from Kami et al. (2016c).