Starting from the ion energy balance equation for a Tokamak including heating by Transit Time Magnetic Pumping (TTMP), a remarkably simple equation, giving the increase of the ion temperature, is obtained, which is largely independent of the nature of the electron energy losses. It is shown that an experiment with TTMP heating on a relatively small Tokamak with a sufficiently small aspect ratio can, in principle, allow the transition from the intermediate to the low-collision diffusion regime to be reached.