Physical Exercise & Your Body
By Columba Quigley (MD)
We are always encouraged to be physically active. There are very good reasons why your body needs exercise on a regular basis, and why having it as a daily routine helps keep you healthy and well.
First, let's see what happens in your body when you exercise:
- Your muscles
All exercise gets your muscles moving. This means that your muscle cells need to work harder. The powerhouses of the cells are the mitochondria. They do all the heavy-duty stuff to keep your muscles moving. With more exercise, your muscle cells make more mitochondria. More mitochondria means more powerful muscles.
- Your fat cells
When you exercise, your body needs more energy to do the extra work. It gets this from your fat cells. They release fat into your bloodstream, and this becomes the energy your hard working muscle cells need. As your fat cells shrink, your body finds it easier to maintain a healthy weight.
- Your heart
Your heart is a muscle too. When you exercise, it pumps blood all around your body. The blood has oxygen that your cells need to do their jobs properly. The more you exercise, the stronger your heart becomes. This means that more oxygen gets to your cells, so they can do all their jobs better.
- Your brain
Your brain is made up of billions of cells, called neurons. When you exercise, your brain makes new neurons. These neurons are mainly in a part of your brain called the hippocampus. The hippocampus is your brain's centre for learning and memory. This means that regular exercise boosts your concentration and memory, so you do better at school!
- Feeling good
When you exercise, your brain releases more chemicals, like serotonin and dopamine. These chemicals improve your mood, and make you happier and less stressed!
You also get to spend time with your friends when exercising together.
Now, let's see what can happen to your body later on if you don't exercise regularly throughout your life:
- Your heart might not work so well
This means that your blood doesn't flow properly and pushes harder against the sides of your blood vessels. After a while, this damages your blood vessels. Eventually, even your heart can get damaged.
- There may be too much fat in your blood
The name for this type of fat is cholesterol. If you have too much, it can leave fatty lumps along the sides of your blood vessels. This means that your blood cannot flow properly and your blood vessels may become blocked. Not enough oxygen gets to your cells, so they can't do all the jobs they normally do. When this happens, parts of your body, like your heart and your brain, can get damaged.
- You might be at a higher risk of developing diabetes
Regular exercise means you are less likely to develop Type 2 Diabetes. With diabetes, the glucose in your blood cannot get into your cells, so it builds up in your blood and is swept around your body.
If your blood glucose is high over a long time, it can cause kidney problems, and can also damage your heart and brain.
- You may have weak bones
Some people get osteoporosis when they are older. This means their bones are weak and thin. Weak bones break more easily. Regular exercise makes your bones strong, so you are less likely to get osteoporosis later on.
Although regular exercise does not always stop these things happening, it does make them less likely, and helps keep you healthy and well.
You need to do three different types of exercise every week:
- Muscle strengthening
- Bone strengthening
Like all muscles, your heart likes a good workout too! It gets this with aerobic exercise, which makes your heart pump faster. With regular aerobic exercise, your heart gets stronger. This means it gets better at pumping blood and oxygen all round your body.
Aerobic exercise is when you:
- Ride your bike
- Play football
Muscle Strengthening Exercise
With regular workouts, your muscles get stronger. This means they can keep going for longer without getting tired. Strong muscles protect your joints too, so you're less likely to get injured.
Different exercises use different muscles:
- Push-ups & tugs of war build strong arms
- Running & biking build strong legs
Bone Strengthening Exercise
These help bone growth. Skipping, jumping, playing hopscotch, running and gymnastics keep your bones healthy and strong.
To stay healthy, you need one hour of aerobic exercise a day and muscle and bone-strengthening exercises three times a week.
There are also some other simple things you can do every day:
- Getting off the bus one stop earlier
- Using the stairs
- Playing fun games with your friends
- Is good for you & makes you feel good
- Gives you more energy & makes you fit & strong
- Helps you keep a healthy body weight & boosts your brain & mood
If you don't exercise, it can cause problems for your body later on.
To stay healthy, you need to do three types of exercise regularly: aerobic, muscle strengthening & bone strengthening.
About Dr. Columba Quigley (MD)
Dr. Columba Quigley is Managing Editor at Medikidz, a charity that provides children and teenagers with informative, accessible and fun comic books to help them understand their bodies and illness.