My text book (*Fundamentals of Physics* by Halliday et al.) mentions the following about the work done in internal energy transfers: > An initially stationary ice-skater pushes away from a railing and then > slides over the ice. Her kinetic energy increases > because of an external force F on her from the rail. However, that > force does not transfer energy from the rail to her. Thus, the force > does no work on her. Rather, her kinetic energy increases as a result > of internal transfers from the biochemical energy in her muscles. This is confusing me a lot. The energy transfer is clearly internal but work must be done by the force as work done is **defined** as the (dot) product of force and displacement and the definition makes no reference to any transfer of energy. I thought work done by a force just means that the force is Causing a transfer of energy To (or from) an object, and gives no information about whether the energy js coming from the object exerting the force. **Edit:** My confusion is not over whether work is being done or not but which force is doing the work which ends up causing the change in kinetic energy