Page 10 - Healthy Living and Hot Water

Hot Water & Heart Health

Our heart pumps blood through the circulatory systems (arteries and veins) to all

parts of the body. The veins and arteries expand and contract depending on the volume

of blood being pumped. Blood circulates oxygen and nutrients throughout the body

and carries waste away from cells. When we exert ourselves or when we exercise, our

hearts pump faster and stretch to pump more blood per stroke in order to transport

needed oxygen and nutrients throughout the body. When we exercise, our hearts
adjust in two ways to make sure we get enough oxygen and nutrients to wherever they

are needed. First, the heart beats faster; this is called our heart rate or pulse rate.

Second, the heart stretches to pump more blood with every stroke; the amount of blood

that the heart pumps in each beat, or stroke, is called our “stroke volume.”

However, when we exercise regularly, we can improve or increase our stroke volume.

Thus, stroke volume is a key measure about our heart’s health. When we get in the
water, our heart stretches as it does during exercise, even if we are just soaking in the

water. Here is how that happens: During immersion, the water exerts pressure on all

parts of the body, including the arteries and veins that carry blood throughout the

body. The water’s pressure on our legs and arms pushes blood toward the chest cavity,

increasing blood flow to the heart by about one third (33percent). Since more blood is

being pushed to our heart, it adjusts by stretching. When we are in the water, our heart
pumps more blood per beat. So, our pulse rate may increase or decrease depending on

the temperature of the water and if we are exerting ourselves or not. Although the

arteries and veins, which circulate blood, are being compressed from the water

pressure, they also must adjust to the higher output from the heart. The arteries

expand (dilate), working against the water pressure to allow higher blood volume to

move throughout the body.

Therefore, when a person is immersed in warm water, the heart is working harder and
more efficiently, like it does when we exercise. The arteries and veins dilate to carry

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