The heart #2

Let’s take a look at two other another examples and review what I told you last week. In the first one, we are doing a light jog and our heart rate is around 120 BPM. In the second one, we are running with all our might for one minute and our heart rate is around 170 BPM. If we put that into the equation:

1)                                                                                                                           2) 

Q = 120 BPM * 70mL                                                                                        Q = 170 BPM * 70mL

Q= 8400mL                                                                                                        Q= 11900mL

Q=8,40L                                                                                                             Q= 11,90L

Our bodies are made so that they can adapt to various stressors. Exercising is one of those stressors and when we start to exercise, we slowly increase our cardio endurance. This happens on many planes, but if we just look at our hearts, this can be seen as a lowered heart rate during exercising, due to an increased volume of our heart (SV) (the heart does not need to work so hard if it pumps a bigger volume of the blood).

To simplify this, let me show you another example while doing a light jog after about 3 months of training. SV rises to 80mL, so to pump 8,40L of blood, our heart needs to beat only 105 times per minute. That is a 15BPM drop in a very small timeframe of exercising. So the same cardiac output can be sustained at a lower heart rate and on top of that, it also lowers your blood pressure. But don’t think that this only applies while exercising. The effects of this can be seen even when we are resting.

Now, let’s take a really quick look at our vascular system. It is made out of veins, arteries and capillaries. Veins carry the blood into the heart, arteries carry it out of the heart and the capillaries are where the magic of gas diffusion happens. Gas diffusion is a term that is used to describe the moving of a gas from a higher concentration to the lower concentration.

Red blood cells carry both oxygen and carbon dioxide. When we breathe in, our lunges fill up with air which is rich in oxygen and the red blood cells take it and carry it into the left part of the heart. This happens because our lunges are enveloped in thin, hair like capillaries thus making it easy for gasses to pass from the lungs to the blood stream. That is called the pulmonary circulation. The oxygen rich blood travels through the left part of the heart and to every cell in our body, where again it reaches the smallest capillaries around muscles and other tissues. There, the blood cells give the oxygen to the cells and take carbon dioxide, other gasses, waste, ions, hormones and other things. The carbon dioxide rich blood then travels to the right part of the heart and is then pumped back to the lunges. This part is called the systemic circulation.

So now we already know, that the heart adapts to regular exercise, but what about the vascular system? The number of capillaries rises and creates a bigger surface for blood to deliver oxygen. On top of that, cell organelles that are responsible for energy production – mitochondria rises greatly so now, our bodies are more adapted to oxygen usage. And to make things even more efficient, the number of enzymes in the mitochondria that are directly responsible for creating energy rises as well.

And for the end, let me just summarize all the benefits that enhancing your cardiovascular fitness level will bring you.

-          It lowers your heart rate and it lowers your blood pressure,

-          In increases the size of your heart and improves your cardiac output,

-          It increases the number of capillaries in muscles and tissues like lunges,

-          It increases energy production in muscle cells,

-          It gives you more energy in your daily life.

Until next time, keep strong and be kind.

Picture taken from: http://tiny.cc/3pvmhw