(i) For trick number one, the mitochondria must survive transfer from an intracellular environment to an extracellular one. This raises the question of how mitochondria survive high extracellular Ca²⁺ concentrations. (ii) For trick number two, mitochondria must produce ATP to support contraction. We ask: how can extracellular mitochondria produce ATP and how can extracellular ATP support contraction? (iii) For trick number three, a sufficient number of mitochondria must pass through the cell membrane to contribute to ATP production by the host cell. This prompts the questions of whether and how viable mitochondria actually enter myocytes and cross endothelial/vascular barriers, and do enough mitochondria do so to make a difference for ATP production?