I grew up and have spent most of my life thinking that Cardiovascular exercise was super important – How many of us have grown up thinking – if you run and sweat and raise your heart rate you burn calories and you’re doing yourself a favor? Until recently I thought this and believed it as well…. Biomechanist, Katy Bowman (founder of Nutritious Movement™) has changed my outlook on Cardiovascular exercise and I will try to share it here with you…
Here’s my attempt to break it down for you.
- The body consists of cells and these cells need oxygen. Oxygen is their food. The blood carries oxygen to all the cells of the body. How does the blood get around??
- In a nutshell, when you move, blood begins to circulate. We tend to think and believe that it is the heart’s sole responsibility to pump the blood around. However, what about the musculoskeletal system’s role in helping to move that blood around and of course, the physics of blood flow: hemodynamics!
- Hemodynamics helps to explain the dynamics of the blood flow. The blood needs to get to its final destination which is the capillary beds (no one seems to talk about the capillaries, these branch off of the arterioles, which branch off of the arteries.) And obviously the understanding of the capillary system would take awhile to explain. But the idea here is that oxygenated blood has a journey and the number of capillaries you have is changing all the time based on what you are or aren’t doing.
- So a muscle begins to work, The mechanical stimulation of a muscle working causes the walls of the arterioles to relax and open which causes a drop in pressure that pulls blood from the arteries to the capillaries. The working muscles pull the blood to the tissues that need it. As Katy Bowman in her book Move Your DNA: Restore Your Health Through Natural Movement puts it, “Within a sedentary culture, the heart becomes the sole mover of blood. This is not ‘how the body works’, but how the body operates in a movement drought.” (p198) Our oxygen delivery system depends on frequent and constantly varying muscle use, those tiny capillaries rely on the use of the musculoskeletal system to get those cells fed. Your heart is pumping all the time regardless but can you imagine the load on your system after you have been sitting or been sedentary all day and then asking your body to do a bout of intense exercise, can you imagine the stress it will encounter? And usually, because so few muscles have worked the bulk of that sedentary time we are usually asking only certain muscles to all of a sudden work.
Katy in a recent podcast says, “the definition of cardio has more to do with the effects of movement (the results) rather than the movement itself.” Most studies are measuring the result of what you did, what exercise you did and deeming it affective as opposed to the actual movement you did? what muscles were working? the loads to those muscles and the geometry related to it. “Our idea of cardio comes from doing nothing the bulk of the time, and then doing something at a higher intensity vs. the benefit of your heart rate going up and down throughout the day”
So in a nutshell, there are lots of ways to get your heart rate up but if we are only getting the heart rate up in 1 way, then this means that parts of the body are being used and others are not resulting in oxygen goes to those places and does not to others. The more muscles involved the better you are actually feeding the cells of the entire body. If you don’t use it you lose it, basically.
We need to move but I think rethinking how we have thought narrowly about cardiovascular exercise can change. Move, move more, and more variety of movements. More all over movements, with varied loads, and varied geometry. There is definitely an argument for cross training and I still think all those contemporary dance classes I have taken are a great example of whole body movement.
Consider, taking a walk, picking up groceries, carrying them, putting them down, picking them up, carry them up your 4 flights of stairs. Does this get your heart going? Of course it does!by