A method of altering energy metabolism in a recipient cell including: identifying the recipient cell as being in need of altering its oxidative phosphorylation status, obtaining exogenous mitochondria, and introducing into the recipient cell the exogenously obtained mitochondria, wherein the exogenously obtained mitochondria functions in the recipient cell to increase or decrease oxidative phosphorylation and/or glycolysis. Also disclosed are isolated cells that include an exogenous mitochondria, wherein the cell demonstrates increased energy metabolism compared to a control cell of the same type but wherein the control cell lacks exogenously added mitochondria. Also disclosed are methods of treating a subject suffering from ischemia or a mitochondrial dysfunction including administering one or more group of isolated cells including exogenous mitochondria as disclosed herein to the subject, wherein the one or more isolated cell including exogenous mitochondria improve symptoms of the ischemia or the mitochondrial dysfunction.
