Biochemical efficiency and intrinsic shortening speed in selected vertebrate fast and slow muscles

The biochemical efficiency was measured in iodoacetate N2 and NaCN-treated muscles by dividing the work done by the amount of phosphoryl creatine hydrolysed when contracting at their optimum velocity. An inverse relationship was found between the intrinsic speed of shortening (Vmax) of the muscles and their mechanochemical efficiency.