Fig. 6.  Sensory-motor and nociceptive responses in HCR and LCR rats. (A ) Median and interquartile range (IQR) show no difference in paw withdrawal latency in response to von Frey hair stimulation between high capacity runners (HCR, n = 6) and low capacity runners (LCR, n = 6). (B ) In a separate group of HCR (n = 6) and LCR (n = 6) rats Hargreaves testing was performed with no other manipulation. These measures of baseline nociception revealed LCR animals to have significantly shorter paw withdrawal latency than the HCR rats.46(C ) HCR and LCR animals differed significantly in the time needed to recover from chronic constriction injury of the sciatic nerve, a model of a chronic pain. Low intrinsic aerobic capacity (LCR) rats (n = 7) revealed a delayed recovery from peripheral neuropathy compared with high intrinsic aerobic capacity (HCR) rats (n = 7). Asterisks indicate statistically significant differences at specific time points after experimentally induced injury of the sciatic nerve. For LCR and HCR rats at 7 and 14 days after sciatic nerve injury, there was a significantly shorter latency for paw withdrawal of the injured hind limb. The LCR rats showed hyperalgesia for a month, whereas the HCR rats recovered in 2 weeks.