Fig. 1. GLUT-4 abundance in gastrocnemius muscle was much higher in the selectively bred `high runner' (HR) lines of mice than in non-selected control (C) lines after five days of wheel access (Group 1, as outlined in Table 1). Clearly, this differential was not a simple linear function of the amount of wheel running performed by individual mice on the previous night (Table 2, P=0.9573 for effect of wheel revolutions). As discussed in the text, this seems to represent a case of increased `self-induced adaptive plasticity' in the HR lines of mice (Swallow et al., 2005; Garland and Kelly, 2006). A representative western blot for GLUT-4 from six individuals is also shown.