So you know you need to exercise or that it would benefit you to do so. You hear this message quite often, especially in connection with being overweight and the dangers of it. But most often when we start to exercise we do so because we are hoping it will change how our bodies look on the outside. We may become aware of other benefits along the way, that we can’t see. Far too often the fact that we are solely focussed on the outside, prevents us from appreciating the inner benefits we are accruing by exercising. That’s why it can be very useful to focus on the progress of your exercise performance sometimes. Think back to when you were just starting, what has changed in your performance and in how you feel, and what does that indicate is happening on the inside. Too many people give up on exercise just when they are starting to reap the real benefits because they can’t see them. Short term thinking prevents us from planning for our long term health.
What does exercise do?
There are many different adaptations that occur inside the body in response to exercise. There are short term changes that happen while you are exercising. Over time as you repeat the exercise, the immediate changes in the body bring about long term changes. Both can benefit us. Physiologic responses to exercise occur in many different systems of the body, cardiovascular, respiratory, musculoskeletal, endocrine, immune, nervous, circulatory, psychological, and also in the structure of the brain.
Immediate effects of exercise
So what are the immediate changes in the body as we are exercising? Well, without some changes we wouldn’t be able to perform the exercise. As soon as we start to move more vigorously our bodies see an increased need for energy in order to keep moving. This means your cardiovascular, respiratory, muscular, and energy systems all need to work harder to transport energy and to take away waste products. More oxygen is needed to be taken in and transported to the muscles. This causes the lungs to breathe faster and deeper to take in more oxygen, which is taken to the heart. The heart starts contracting (beating) faster, which in turn causes the blood to travel faster around the body to transport the oxygen to the muscles and to transport carbon dioxide away from the muscles. Lactic acid production in the muscles increases. Your blood pressure increases. More blood is directed to the muscles that need it, and away from other areas of the body. The cellular respiration causes the muscles to become warm and may cause you to sweat. Your joints become more lubricated due to the movement. You may feel more flexible and feel your range of movement has temporarily increased (maximum size of the movement). The muscles must increase the rate of producing ATP, the chemical compound necessary for energy. The endocrine system releases many different hormones in order to make increased glucose/glycogen and fatty acids available, and the sympathetic nervous system suppresses the release of insulin. The hypothalamus in the brain coordinates everything via the autonomic nervous system and the endocrine system. The increase in endorphin production is what causes us to feel more mentally relaxed and increased dopamine makes us feel more alert and focussed. After the exercise the serotonin levels rise which also makes us feel happier, gives us improved sleep and can work as an appetite suppressant/balancer.
This is a simplified version of course. And as you know science is one of those things, you can go in as deep as you like and never get to the bottom. There are still many mechanisms in the body we do not fully understand, and studies are forever ongoing.
Effects during rest
After exercising, the body needs to rest and recover. It is during the rest that the body makes adaptations. It is these adaptations over time that make us fitter, stronger and healthier. Of course the type of adaptations depend on the types of exercise performed but we will presume a comprehensive mix is performed here.
Long term effects of regular exercise
All the short term adaptations that occur during exercise make long term changes when repeated over time. Some of the long term adaptations to exercise are the ones we can see, our body visually changing. This is due to the change of body composition, i.e muscle hypertrophy and tone (muscle grows and becomes firmer), reduction of body fat. We may also notice improved posture and movement. The growth and tone of the muscle go hand in hand with increased strength of the muscles, the tendons and the ligaments, and also the bones. The heart is one of the muscles that becomes stronger, thus being able to move more blood at every beat and needing to beat less frequently and having an increased maximum output. This and the increased elasticity of the veins and arteries results in lowered resting blood pressure. Increased amounts of capillaries (small blood vessels) are made in the muscles and in the lungs, and the number of red blood cells increases, in order to make transporting oxygen and nutrients around the body more efficient. The lungs increase in capacity and volume, and increase the number of alveoli (small air sacks which pass molecules from the air to the blood and back again). The breathing muscles, the diaphragm and the intercostals, become stronger. This means the amount of oxygen that can reach the muscles and the amount of carbon dioxide that can be removed is increased. The energy production systems become more efficient and metabolism increases. Stamina is improved. The range of movement and flexibility is improved and the joints move more freely. The tolerance to lactic acid improves. HDL cholesterol (the good cholesterol) amounts increase and triglyceride levels decrease. Blood sugar levels can be decreased and insulin may work better. Our motor skills improve as a result of new and regular movement patterns. It has also been shown that exercise can help the immune system find and deal with pathogens and regular exercise slows down age-related deterioration of the immune system.
We already mentioned the release of mood-enhancing hormones. It has been said that not exercising when you feel down is like not taking a pain killer when you have a headache. In the long run, exercise can help us to manage stress, anxiety disorders and depression. But also the latest research suggests regular exercise actually improves brain function and can help ward off dementia. It has been found that the improved blood flow to the brain can protect brain cells from degeneration and feed the growth of new brain cells by BDNF (brain-derived neurotrophic factor). In a study done at the University of British Columbia it was found that exercise seems to boost the size of the hippocampus, the area of brain involved in learning and verbal memory. (Heidi Godman, Harward Health Letter, April 5 2018). Many studies suggest that parts of the brain that control thinking and memory are larger in people who exercise. (Dr. Scott McGinnis, Neurologist and instructor at Harward Medical School).
Exercise benefits us
There is undeniable evidence that regular physical activity not only allows us to be a better functioning, stronger, more energetic, healthier version of ourselves now, but also helps to prevent deterioration associated with aging and/or sedentary lifestyle. It helps prevent several chronic diseases and is associated with a reduced risk of premature death. We can see from the adaptations discussed above why the risk of heart disease, heart attack, stroke and Type 2 diabetes is reduced. Also Colon, breast, uterine and lung cancer may be prevented. We can prevent or alleviate many age-related conditions such as osteoarthritis, osteoporosis, falls and hip fracture, respiratory diseases, general low fitness, weakness, bad balance and overall poor function. Regular exercise has been described as the only real fountain of youth. For example in a research study done at the University of Birmingham, a group of older people who had exercised all their lives was compared to another group of same age non-exercisers and a group of young people. The results showed that the long term exercising older people had the immunity, muscle mass, and cholesterol levels of a young person. (Science News, March 8, 2018). Among some of the other benefits, In men erectile dysfunction may be prevented or improved, and in women sexual arousal may be improved. Not to mention just feeling better about yourself because you are looking after yourself.
How to get the benefits of exercise
And it’s free! Well once we know what to do, we can do it almost anywhere, anytime convenient, giving ourselves the gifts that are the benefits accrued. So how much exercise is enough to get the benefits and how much effort do you need to put in? The World Health Organisation (WHO) recommends half an hour of moderate exercise most days of the week, or 150 minutes in a week. If you are new to exercise and this seems daunting, the good news is that many things you may already be doing are considered physical exercise by the WHO. For example mowing the lawn, washing the car, in fact anything that involves physical movement. On top of your normal daily activities, you could start with five minutes a day and increase the amount by five or ten minutes every week until you reach your goal. Sometimes people who are not used to exercise are frightened of getting out of breath or of feeling their heart beating faster. But this effect is necessary to give the cardio-respiratory system the work out that will enable it to get fitter. Once you get accustomed to this and reach your time goals, you may want to keep experimenting with your exercise, try increasing intensity and mixing it up. Of course, we don’t want to overtrain. But people who exercise at levels above the recommended guidelines are likely to reap further health benefits. The risk of chronic disease increases with age so earlier we start to engage in more exercise the better.