Exercise is good for us – that’s a fact. What we might not know is what happens to our bodies during and after exercise.
I’ve put together this presentation to give you an overview of how our heart and our lungs adapt when we exercise an a regular basis.
For anyone who doesn’t have sound, I’ve summarised the audio in the text below.
Today I’m going to run through how exercise (both resistance and cardio) benefits our cardiorespiratory system.
We know that exercise in general is good for us, and I’m going to give you an overview of exactly how our heart and lungs reacts and adapts when we exercise on a regular basis.
Firstly to differentiate between physical activity and exercise, as they strictly aren’t the same thing.
Physical activity can be defined as any movement of the body that requires energy expenditure. A good example of this is walking up the stairs.
Exercise is a type of physical activity, but one that requires physical effort.
So what should your typical exercise/ workout session look like?
No matter whether you’re focusing on CV, resistance or both, you should always incorporate a warm up, and a cool down (which includes stretching the muscles worked during exercise).
Warming up, cooling down and stretching are very likely to be neglected – especially when time is tight. Skipping them though, can be detrimental to the exercise session and potentially to yourself.
Let’s look at why…
A warm up should last for a minimum of 5 minutes (depending on how long you plan to workout for). During the warm up, our muscle temperature increases. Warm muscles move more freely, and hence this reduces the risk of injuring the muscles during the main session.
Blood temperature also increases, which results in more blood being available to the working muscles. This improves our endurance, meaning we’ll be able to work for longer during the main session.
Our blood vessels will dilate (i.e expand), which means there is less stress on our heats as blood around the body increases.
As our muscles are warmer, their range of motion will be greater, meaning larger joints can reach their full movement potential.
Hormonal changes in the body that are triggered by the warm up activity make carbs and fatty acids available to fuel our workout.
Heat dissipation mechanisms are activated – these enable the body to cool effectively via evaporation of sweat and increased skin blood flow.
So the warm up essentially prepares the body for the main session that lies ahead. Without it the body won’t be as efficient during the main session, and the risk of injury is increased.
When it comes to the main exercise session, whether it be resistance or CV, there are both short term and long term effects on the body.
Short term effects are occur only during exercise, and the body will return to normal during the cool-down.
Let’s look at the short term changes on the cardiovascular system.
Pretty quickly our heart rate increases – which means a greater volume of blood is pumped from the heart per beat and thus per minute.
The arteries that supply blood to the working muscles widen to enable a greater supply of blood.
To get this greater supply, blood flow is actually diverted to the working muscles from non essential organs such as the stomach and intestines via constriction of the blood vessels.
The additional blood flow means that our systolic blood pressure increases.
All short term changes occur because the body is working hard. So over time, how does the body adapt?
Our heart rate decreases, and being a muscle, it responds to the demands put on it during exercise by becoming stronger. As the heart is stronger, a greater volume of blood is pumped from it. And this increase in blood is achieved even though the heart is beating at a lower rate.
There is also an improvement in how oxygen is carried to our red blood cells, and improved gaseous exchange between muscles and the lunges. Gas exchange being the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs.
Our blood cholesterol can also be lowered with exercise.
As with our cardiovascular system, our respiratory system also has short and long term reactions to exercise.
Once we start exercising, our breathing rate will increase. This results in:
Less air in the lungs after we exhale
A greater volume of carbon dioxide is removed and oxygen uptake increased.
We also move more air in and out of our lungs in a single breath.
Again, these changes occur because our body is working hard. So how does the respiratory system respond in the long term?
Our breathing rate decreases, but we can also move more air in and out of our lungs in a single breath. Because we’re moving more air out of the lunges, there is less left after we exhale.
Matching the short term effects of exercise, there are long term improvements in delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. This is achieved via the formation of new capillaries in the lungs.
As you can see, over time, exercise strengthens our cardiorespiratory system and makes it more efficient. Remember though, that you need to push your body sufficiently for these changes to occur.
One thing we mustn’t forget is the cool down!
Essentially the cool down will allow the body to gently return to its pre exercise state. Hence, our breathing rate deceases and returns to normal, as does our heart rate. Our body temperature will also begin to decrease and return to normal.
You can obviously just stop exercising, but this would result in a sudden drop in heart rate, which can have a couple of nasty side effects…
If we did suddenly stop dead following vigorous exercise, blood pooling in the large muscles of the legs can occur – as the heart rate will suddenly drop and no longer be pumping blood around the body at the same rate.
A sudden drop in heart rate can also result in dizziness and/ or fainting.
A cool down of just 5-10 minutes can ensure the body is gently returned to pre exercise state.
That brings me to the end of my overview of how exercise effects our cardiorespiratory system. I hope you found it interesting. If you do have any questions, please feel free to contact me via email or FB messenger.
If there’s anything else you’d like to learn more about, again please let me know.