The loss of muscle mass in ageing, also known as sarcopenia, is associated with a decline in muscle quality. There will also be a greater accumulation of fat and connective tissue in the muscle of the older person, and this effectively reduces the true measure of the functional parts of muscle, the muscle fibres. Indeed, in older persons, there is a shift in the type of muscle fibre toward the slow twitch type 1 fibre, which further weakens muscle function, reducing the speed and strength of contraction. The decline in muscle mass and function is not uniformly spread across the body. It is greater in the lower than the upper limbs and the greater decline in muscle function in the legs agrees with findings that in type 2 diabetes, the greatest level of insulin resistance is in the lower part of the body.