  Intrinsically coupled nonlinear systems present different oscillating
components that exchange energy among themselves. A paradigmatic example is the
spring pendulum, which displays spring, pendulum, and coupled oscillations. We
analyze the energy exchanges among the oscillations, and obtain that it is
enhanced for chaotic orbits. Moreover, the highest rates of energy exchange for
the coupling occur along the homoclinic tangle of the primary hyperbolic point
embedded in a chaotic sea. The results show a clear relation between internal
energy exchanges and the dynamics of a coupled system.
