Exercise. Many of us won’t even entertain the idea, convincing ourselves that we just don’t have the time, when in fact, we do. Just two and a half hours a week could not only improve the fitness of your body, but also your mind.
Why does exercise make us feel good?
When we exercise, neurotransmitters (chemical messengers) known as endorphins are released and distributed across our nervous system. Endorphins bind to opioid receptors in the brain, which act to block pain transmission, which can lead to the sense of euphoria often experienced whilst completing exercise.
One hypothesis is that exercise increases blood flow to the brain as well as the activity of the hypothalamic-pituitary-adrenal (HPA) axis, which is associated with the physiological response to stress. The HPA axis communicates with other areas of the brain such as the amygdala which generates a sense of fear in response to stress; the limbic system, responsible for emotions and motivation; and the hippocampus, an area of the brain associated with memory formation, which itself can be linked to an individual’s mood and motivation.
Another theory is that exercise increases the synthesis and release of neurotrophic (brain-supporting) factors such as brain-derived neurotrophic factor (BDNF) and insulin-like growth factor (IGF-1). This increase is not only associated with improved cognitive function, but also a protective effect on the brain by stimulating neurogenesis (growth and development of nervous tissue)
and angiogenesis (the formation of new blood vessels), which all act to support the function of the brain.
Research on animal models has shown that BDNF is essential to hippocampal function, including learning and memory. Several studies have also shown that exercise can increase the level of BDNF in the rat hippocampus, which leads to a response similar to that of antidepressants.
IGF-1 production also increases with exercise and is shown to be lower in the elderly, whose cognitive function is in decline, supporting the hypothesis that exercise may actually improve cognitive function.
Exercise – Just what the doctor ordered?
The monoamine hypothesis of depression suggests that depression occurs due to decreased levels of monoamines such as noradrenaline, serotonin and dopamine. Many antidepressants aim to increase the synaptic transmission of these chemicals in order to alleviate a patient’s symptoms such as a lack of energy, attention issues and anxiety. Interestingly, exercise has been observed to increase the production and release of all three neurotransmitters, contributing to the improvement observed in patients who take up regular exercise.
Exercise-related changes in patients with depression are also linked to the fact that exercise can offer a distraction from the stresses of daily life as well as promoting a feeling of self-efficacy. Group fitness classes may also provide the social support that patients often require and can help them to feel less isolated.
The improvement observed in those with anxiety who participate in exercise are thought to work in a similar way to depression, with the decreased stress response being linked to a general decrease in muscle tension and heart rate as a result of the exercise.
Exercise has even been suggested to help those with schizophrenia, who are often susceptible to weight gain due to the use of antipsychotic drugs. A three month study showed that just 30 minutes of moderate exercise, three times a week was enough to observe an improvement in weight control, blood pressure and overall fitness levels of the patients. It was also noted that the 30 minutes need not be a continuous bout of exercise, but may still beneficial even if broken down into three ten-minute sessions.
It is clear that pharmacological interventions aren’t the only thing that could help patients – exercise is important too.
So what counts as ‘moderate’ exercise?
Moderate exercise doesn’t have to be something that leaves you a broken shell of a human, panting for dear life, it can just be an activity that raises your heart rate more than a stroll would, or something that makes you breathe a bit heavier than usual. Some examples of moderate exercise include walking, swimming, gardening, cycling and dancing. Increasing your activity levels doesn’t have to start with hitting the gym three times a week, it can begin with small changes to your daily routine such as taking the stairs instead of the lift, or choosing to walk a journey you would usually take in the car.
Exercise doesn’t just benefit the above medical conditions, but it can also lead to general improvements on mental health such as:
Improving the quality of sleep
Increasing self esteem
Sense of achievement
Cognitive function including focus
So exercise not only makes you feel good, it can improve your overall mental health and with it your performance at work, in exams and everyday life too.It is important to note that too much exercise can lead to problems in itself such as injuries and overexertion and it is therefore important to take rest days and listen to your body if you are in pain. As is the mantra of most health and fitness gurus – everything in moderation is the key to good health not just physically, but mentally too.