However, the law of conservation of energy provides useful information. Since the external work done on the skater is zero, there is no energy input into the system consisting of the skater. Therefore, the law of energy conservation applied to the skater implies that the skater's total energy remains constant while he pushes off the wall. The skater's total energy consists of several kinds of energy: mainly his translational kinetic energy and internal energy in the form of thermal energy and chemical energy. When the skater pushes off the wall, his translational kinetic energy and his thermal energy increase. (The skater will get a bit warmer.) This energy increase must be compensated by a corresponding decrease in the skater's chemical energy as chemical energy is transformed in his muscles during the process.