During cellular respiration, specifically during the conversion of glucose to pyruvic acid (a part of glycolysis), two main additional products are formed along with the four ATP: two molecules of NADH and two molecules of pyruvic acid. However, of the options you've provided, the correct response regarding another product produced as a result of this reaction would be:
heat
While water is produced later during the electron transport chain stage of cellular respiration, it is not produced during the initial conversion of glucose to pyruvic acid.