Fractional 2-deoxyglucose (2[3H]DG) uptake in the gastrocnemius of mice expressing 0-, 0.5-, 1.0- and ∼3.5-fold wild-type GLUT4 levels during exercise or in the sedentary state. Fractional 2-deoxyglucose (2[3H]DG) uptake in the gastrocnemius of mice expressing 0-, 0.5-, 1.0- and ∼3.5-fold wild-type GLUT4 levels during exercise or in the sedentary state. GLUT4 only affected fractional 2[3H]DG uptake in the sedentary state when it was overexpressed. However, the absence of GLUT4 caused a marked attenuation of fractional 2[3H]DG uptake during exercise regardless of whether HK II was overexpressed. HK II overexpression had no effect on the response during saline infusion but increased the exercise. Data points are means ± s.e.m. of 8–11 in vivo mouse experiments. Modified from Wasserman (Wasserman, 2009). David H. Wasserman et al. J Exp Biol 2011;214:254-262 © 2011.