The science of energy metabolism - what role does our food have in energy production? What is energy? How do we get energy? I explore how our body generates energy, the function of the cardiorespiratory and circulatory systems, haemoglobin, heme-iron vs non-heme iron (and what that means for our blood), energy metabolism, the role of caffeine and creatine supplementation in exercise performance, glycolysis, glycogenolysis, gluconeogenesis, the difference between saturated and unsaturated fat (and what that means for energy metabolism).