Energy Metabolism

The 3 main sources of energy in your body are fatty acids, sugars and protein (disregarding alcohol).

During starvation, utilisation of fatty acids from intracellular lipid droplets is increased, and autophagy mediated.[1]

Not just daily exercise increases lipolysis in general [2], but also acute exercise increases lipolysis, specifically in the liver (not in skeletal muscle), accompanied by increased serum levels of free fatty acid, glycerol and ketone body.[3]

Better fitness is not associated with lower dietary fat intakes.[4] Increased physical activity reduces serum triglyceride levels.[5] At similar levels mean VO2, tennis match play relies more on glycolysis and glycogenolysis compared to continuous running exercise.[6]