Lecture 17 - Energy

it is continually making (Adding) and breaking down (losing) components within the body

Muscle - protein balance [affects muscle size, strength and endurance, muscle power] Bone - mineral balance [affects bone strength] Energy - energy balance [affects metabolism, body composition]

human bodies evolved to develop efficient metabolic systems and use ingested food to counter feast-famine cycles

Hunter and gatherer level of physical activity and energy use. these were essential for survival -> our modern life has broken this link, human body has evolved to develop efficient metabolic systems to store and use ingested food to counter feast-famine cycles

Adipose tissue, liver, Skeletal muscle

Exercise intensity and duration

this exercise increases mitochondrial content in the skeletal muscle and the ability to uses Oxygen and metabolise

Low energy use has cumulative effects on metabolism and body composition. low energy use and positive energy balance lead to mitochondrial loss and dysfunction and thus a reduced ability to use oxygen and metabolise. Insufficient shuttling of useful fats into the mitochondria for oxidation (burning), resulting in fat accumulation leading to insulin insensitivity and eventually type 2 diabetes

regular exercise increases the size and number of mitochondria, usage of fat and improves metabolism

Reduced exercise intake leads to loss of stored energy - fat, protein and carbohydrate. Increased energy loss combined with reduced energy intake limits protein loss -maintains muscle mass. reduction in fat stores within fat cells

metabolic level is stable. this is only when there is regular physical activity, genes that control energy expenditure will take a hit if not