We all know that regular exercise is good for us. It strengthens our bones and muscles, keeps our heart and lungs in good condition, helps us to relax and sleep better, helps keep our weight in check and makes us less likely to get sick.
But, exercise does much more than simply get us into shape and help us look good – it also make us feel good. The old adage “healthy body, healthy mind” rings true.
But why does exercise have this remarkable effect on us?
Scientists are still trying to unravel the complexities – but in simple terms, it’s due to a number of “feel good” chemical messengers (hormones) that are released by the brain when we exercise giving us the sensation of wellbeing. These are often termed our ‘happy hormones’!
Three important ones are endorphins, serotonin and dopamine.
Endorphins – the ‘exercise high’ hormone
Endorphins are a powerful hormone released in the brain during aerobic exercise. Endorphins not only give the feeling of euphoria and exhilaration but are a natural pain-killer – three times more potent than morphine! Endorphins also increase pain tolerance and help reduce stress, anxiety, tension anger, confusion and depression. They also improve appetite control and produce an overall feeling of calm, pleasure, and general well-being.
Blood levels of endorphins increase up to five times resting levels during moderately intense exercise lasting around 30 minutes or more. Also, after several months of regular exercise, the body develops an increased sensitivity to endorphins (a higher “high” from the same level of endorphins), and endorphins that are produced tend to stay in your blood for a longer period of time. This makes longer duration exercise easier (you’re feeling less pain!) and it causes your exercise “high” to last for a longer period of time after exercise.
Serotonin – the ‘hormone of happiness’
Serotonin is a key hormone controlling our general mood. It is also involved in regulation of our sleep patterns, appetite, behaviour, memory and learning, sexuality, anger and body temperature. Serotonin is naturally produced in the pineal gland which lies deep at the centre of the brain.
Serotonin levels can become too low because of emotional or physical pressures, poor diet, too much alcohol or caffeine, smoking and no exercise. Low levels of serotonin are often associated with depression, anxiety, apathy, fear, feelings of worthlessness, insomnia and fatigue.
Whilst good diet and healthy lifestyle in general will help to improve serotonin levels, the most effective way of raising it is with regular, moderately vigorous exercise.
Studies have shown that serotonin levels are increased with increased aerobic activity after around 20-30 minutes and the production of serotonin stays increased for some days after the activity.
Exercise is a great way to increase serotonin and help maintain that feeling of ‘happiness’ and joie de vivre.
Dopamine – the ‘pleasure’ hormone
Dopamine has many functions in the brain and is commonly associated with the feelings of pleasure and enjoyment, with motivation, reward and positive behaviour. Dopamine has an important role in muscle movement control and coordination. In fact, low levels of dopamine in certain parts of the brain have been strongly linked to Parkinson disease.
Dopamine also helps regulate the feelings of fullness when we eat, so that we eat until we’re reasonably comfortable and don’t overindulge. But interestingly, a US study indicated that obese individuals have fewer dopamine receptors in the brain resulting in obese people eating more to try to stimulate the dopamine “pleasure” circuits in their brains.
However, not only can exercise can a 30-minute bout of moderately vigorous increase dopamine release but studies show that exercise can help increase the number of dopamine receptors, which can help stop the desire to over-eat. This has led scientists to suggest obese people may be able to boost their dopamine response through exercise instead of eating.
A 30-minute bout of moderately vigorous exercise stimulates the release of dopamine.
So, that’s why a regular 30-minute dose of exercise is a wonderful ‘prescription’ to make you feel good!