How physical activity affects us (Så påverkas vi av fysisk aktivitet)

Lungs and fitness

When you walk quickly or jog, you can become short of breath. This is because your body needs more oxygen. You breathe faster and get more air into your lungs, which provides your blood with more oxygen. Your heart beats faster and pumps more oxygenated blood to your muscles.

These effects are good for our bodies, but they disappear quite quickly after we have finished exercising. To maintain these positive effects, you need to exercise two or three times a week. The exercise should be something that makes you short of breath and increases your heart rate. This is called cardio exercise.

If you exercise regularly, your lungs become stronger and are able to absorb more oxygen. This will improve your endurance and fitness. As your fitness improves, the positive effects remain even when you rest. Good fitness improves our health, quality of life and mood. It also reduces the risk of many serious diseases.

Heart and blood vessels

Exercise is good for the heart and blood vessels. It improves the functioning of the heart, helps to form new blood vessels and improves both blood lipid levels and blood pressure. The heart becomes stronger and pumps more blood every time it beats. This means that your heart does not need to beat so often when you are resting.

Better fitness means both a lower resting heart rate and lower blood pressure. This reduces the strain on the heart and lowers the risk of cardiovascular disease. Exercise also helps us to form new blood vessels, which increases blood flow and provides more oxygen to the muscles.

Exercise reduces the amount of ‘bad’ cholesterol in the blood, while increasing ‘good’ cholesterol. It can also increase the number of red blood cells, which carry oxygen in the blood.

Insulin is a hormone that controls our blood sugar. When you exercise, you need less insulin, which is good for preventing type 2 diabetes.

Muscles

When you use your muscles, there is a lot that happens in your body. Your heart rate increases, your heart pumps more blood, you breathe more quickly and more hormones are released. You need muscles to do things like walking, running, lifting, turning your head and supporting yourself in the event of a fall. Strong muscles also protect your skeleton.

Skeletal muscles are made of muscle cells that form muscle fibres. When you, for example, reach out with your arm to grab something, your brain sends signals to the muscle cells to contract. The more you exert yourself, the more the muscle fibres become activated.

When you exercise, your muscles become stronger. The next time you do the same thing, it will feel easier. The muscles also become better at using energy, so they are able to work for longer without getting tired. After exercise, our muscles need to rest in order to become stronger.

Several things happen in your body when you exercise.

• Hormones such as growth hormone and testosterone increase, which helps muscles to grow.
• More mitochondria (our cells’ ‘power plants’) are formed, which enables muscles to use energy more efficiently and to work for longer.
• The nervous system gets better at activating more muscle fibres, which results in greater strength and speed.
• The body repairs and strengthens muscle fibres, which can have been slightly (although harmlessly) damaged by exercise. This results in muscle soreness, which passes after a few days.

Balance and coordination

Physical activity improves your balance and coordination. This is because it increases blood flow to the brain and improves metabolism. Balance and coordination will also improve if you have strong muscles.

When you exercise regularly, your ability to react improves and you reduce the risk of falling.

You can easily work on your balance at home. Balance and strength exercises need to be done 2–3 times per week to get results.

Exercises to improve balance

Shifting your weight – Stand with legs apart and shift your weight from one leg to the other. Repeat 8–12 times.

Balanced walking – Walk along a line that has been taped onto the floor. Once this exercise feels easy, you can increase the distance.

Walking on heels and toes – Walk on your heels for a certain distance, then on your toes. Gradually increase the distance.

Standing on one leg – Stand on one leg and draw figures of 8 in the air with your other foot. Repeat with the other leg.

Stomach and intestines

Regular exercise affects the stomach in many ways. Increasing the movement of our intestines decreases the risk of constipation. This applies to both cardio exercise and strength training.

Exercise also affects the gut flora, which are the millions of bacteria and microorganisms that live in the intestines. People who exercise regularly have better gut flora than those who do not. Exercise also improves digestion by increasing the blood flow to the digestive system. This helps food to be broken down more effectively and allows nutrients to be absorbed by the gut and passed on to the blood.

Physical activity also reduces inflammation in the body. Increased blood circulation and the production of substances that inhibit inflammation help to relieve problems in the intestines, such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). Exercise can also reduce chronic stress, which is bad for the stomach and intestines.

Mental health and self-confidence

Regular exercise can improve your mental health. Exercise can also help to reduce anxiety and depression.

When you exercise, your brain releases endorphins, which are substances that have a positive effect on your mood. After exercise, endorphins can produce a sense of pleasure and well-being.

Exercise also increases the amount of serotonin and dopamine, which affect our emotions and mood. Higher levels of these substances can reduce depression and anxiety. Exercise also helps the brain to become more flexible and strengthens the body’s stress-response system.

Mental health problems are often linked to sleeping problems. Regular exercise – particularly cardio exercise – can help you to sleep better, with better quality sleep.

Many people enjoy exercising with others – for example, by joining a gym class or a walking group. Exercising with others can also help to combat feelings of loneliness.

When you feel that you are stronger, faster or have more endurance, it can give you a sense of control over your body. It can boost your self-confidence, which can also have a positive impact on other aspects of your life.

Stress

Regular physical activity helps you to manage stress. Exercise affects how the brain and body react to stressful situations and environments.

Exercise lowers the level of the stress hormone cortisol and increases the body’s ’feel-good’ hormone endorphin. The increase in endorphins both during and after exercise increases feelings of calm and well-being. It can also counteract negative emotions such as anxiety and depression that often accompany stress.

Sleep

Exercise can help those who have difficulty falling asleep or who sleep too little. Exercise can help you to establish a good sleeping rhythm, reduce stress and improve sleep, in both the short and the long term.

Regular exercise in daylight increases production of the hormone melatonin. This controls the body’s diurnal rhythm, between sleeping and being awake. Melatonin is particularly important if you have trouble falling asleep at night.

Exercise also helps the nervous system to calm down, which can help us to sleep better. The quality of sleep also improves, especially deep sleep. Deep sleep is important for the brain and body’s ability to recover. And you feel more awake and alert during the day.

Concentration and memory

Physical activity increases blood flow to the brain. This improves oxygenation and increases the nutrition needed by nerve cells, and helps the brain to get rid of harmful substances. This helps to improve your concentration, improve your memory and learn new things more easily.

Light exercise, such as swimming and walking, also increases the production of dopamine and serotonin. These are hormones that are important for concentration and memory.

Regular physical activity increases the brain’s ability to change and adapt. Exercise also stimulates the growth of new nerve cells in the brain.

Aches and pains

It is good to move around if you are in pain or have prolonged aches. This releases the ’feel-good’ hormone endorphin, which acts as the body’s own painkiller. Even if you only exercise once, you might notice an immediate reduction in pain.

Prolonged aches are often associated with inflammation in the body, such as rheumatism. Exercise can lower the levels of substances that cause inflammation and increase the production of substances that counteract inflammation.

Another cause of pain can be that bodily strain is unevenly distributed. Or that the muscles are spastic and tighten without our control. Regular movement and exercise can help muscles to relax.

When you exercise regularly, your muscles become stronger. Muscles relieve the strain on bones and joints, which can reduce aches and pains.

Exercise can also affect how we experience pain. The brain becomes better at processing pain signals and this allows us to feel less pain, even if the cause of the pain remains.

Pain is affected by tiredness, stress and anxiety. If you exercise regularly, you can sleep better and feel less stress. Exercise can also reduce anxiety and depression.

Skeleton, tendons and ligaments

Your skeleton is made of bones, and strong bones reduce the risk of bones breaking. You can strengthen your skeleton by subjecting it to strain. Good exercises for the skeleton include weightlifting, aerobics, volleyball and football. Walking is also good, although not as effective.

Lifting heavy weights might feel like hard work, but the more you lift, the stronger your bones will become. Small shocks from jumping or kicking a ball may feel uncomfortable at first, but after a while your bones will tolerate them better.

Regular exercise, especially strength training, also makes tendons and ligaments stronger and more flexible. This reduces the risk of injury. Exercise also increases the production of collagen, which is important for tendons and ligaments.

Exercise improves blood circulation to the whole body, including tendons and ligaments. Good blood circulation helps injuries to heal and reduces inflammation.

Immune system

Regular exercise strengthens your immune system. Exercise increases the production of immune cells and antibodies that protect against disease. Light exercise, such as brisk walking or cycling, is enough to reduce the risk of colds and other infections.

Exercise also increases the production of anti-inflammatory substances. This is important because chronic inflammation can lead to autoimmune and cardiovascular diseases.

Exercise improves blood circulation and the oxygenation of tissues in the body. This enables immune cells to find infected or inflamed areas more quickly.

Regular exercise also helps to lower levels of the stress hormone cortisol. If cortisol levels are too high for a prolonged period, this can damage the immune system.