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Case Study Essay 2: Autoregulation
As most of us know, if not all, we need food sources (macronutrients) that are consumed
on a daily basis to supply energy through metabolic pathways to support us during exercise.
However, what else happens to our bodies during exercise? When we exercise there is an
increased demand of oxygen of the contracting exercise skeletal muscles, therefore there is a
redistribution of blood during exercise; meaning there is a need to increase blood flow to the
contracting muscles while reducing the blood flow in other areas not as active (Powers &
Howley, 2018, p. 214). This leads to the real question of what regulates the blood flow to various
parts of the body during exercise? While all body tissues have an ability to regulate their own
blood flow for their metabolic needs, skeletal muscles blood flow will increase to match the
demand of the exercise intensity and duration (Powers & Howley, 2018, p. 215). The blood flow
increases about 100 times to the contracting muscles during intense exercise compared to the
blood delivery when at rest. Autoregulation is an essential factor in regulating the blood flow of
the exercising muscles through promoting vasodilation for the increase of blood to these muscles
(Powers & Howley, 2018, p. 216). To simply put it, autoregulation occurs within the body
locally during exercise by an increase production of vasodilators such as ATP, adenosine, nitric
acid, prostaglandins, and endothelium-derived hyperpolarization factors to promote vasodilation
for an increase of blood flow to the contracting muscles (Powers & Howley, 2018, p. 216).
There are three aspects of Autoregulation that play a role in the regulation of blood
distribution to the exercising muscles and tissues. In other words, blood flow is redistributed
from areas that are not momentarily essential at that time to the areas that need the blood that is
carrying the nutrients and oxygen to support the activity (Liberty University, 2021, slides 2-3).
These aspects are known as vasodilation, vasoconstriction, and capillary recruitment. At the
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beginning of exercise from rest is when vasodilation occurs as blood vessels (arteries, capillaries,
arterioles) expand in size to allow for increased blood flow and increased oxygen delivery.
Vasodilation can also occur when exercise intensity has increased. Vasodilation occurs because
the more ATP (energy) needed, the more oxygen and macronutrients are required, thus,
