While exercise may use up energy it paradoxically also boosts our physical, mental and sexual energy levels. How does this happen?
Mitochondia, small energy-producing structures within our cells, are most plentiful in muscle cells because these cells require rapid energy delivery when we exercise or do hard physical work. Regular exercise increases both the mitochondrial size and number. This is one of the main reasons why a person becomes fitter and has more energy available, leading to a greater sense of well-being. When muscles are at rest they prefer to use fatty acids to generate energy but as soon as they become active they switch to glucose for more rapid and efficient energy delivery. Glucose is stored in the muscles in the form of glycogen and muscles with good glycogen stores can exercise for longer without tiring. And, as muscles exercise, they increase in size which then increases the amount of glycogen that can be stored. This means that with regular exercise we develop greater stamina (more energy-producing mitochondia and greater fuel reserves) as well as greater strength (more muscle tissue).
Someone with a sedentary lifestyle has about 1g of glycogen per 100g of muscle while an athlete has much as 4g per 100g. It is therefore little wonder that when we are unfit we quickly exhaust our capacity to deliver energy to our muscle cells. This is experienced, rather discouragingly, as exhaustion, aching muscles and breathlessness when we start to exercise.
But don’t despair. The good news is that if we continue on a sensible exercise programme of 30 minutes of vigorous exercise at least three times a week, the situation quickly improves. Any exercise which makes our body feel warm, increases our heart rate (our pulse should ideally be raised to around 100 beats per minute) and leaves us feeling slightly breathless (we should just be able to keep up a conversation but not sing!) is called aerobic exercise and will help to improve stamina, strength and suppleness. Different exercises convey different benefits in these three different areas with something like strong swimming or running providing maximum stamina development, weight lifting maximum strength development and yoga maximum suppleness development.
Exercise does not all have to happen in one go to be beneficial. An Australian study with 500 men showed that those who took light exercise on a bicycle, stepper or rowing machine with plenty of rests in between were as fit on treadmill tests after one year as those who jogged or walked continuously for their exercise period. And exercise does not have to be in a gym, on a sports field or on the road jogging or cycling. It can be dancing or spot jogging in the kitchen while we wait for the kettle to boil, working in the garden or climbing stairs instead of using the escalator or lift. Getting our bodies to move rapidly in any way will be beneficial.
Exercise confers many other wide-ranging benefits. It helps to:
- Stimulate the release of endorphins in the brain. These are morphine-like chemicals which induce a sense of well-being and lift our mood.
- Reduce anxiety and mild-moderate depression.
- Improve the quality of sleep, especially if the exercise is taken in the morning. Researchers believe that morning exercise helps to set our body clock each day, which helps us feel more awake and energised during the day and appropriately tired at night.
- Avoid cognitive decline associated with ageing. Games such as tennis require a lot of mental as well as physical work and promote mental and physical agility.
- Improve ‘heart health’ by decreasing blood pressure and harmful cholesterol levels.
- Stabilise blood sugar levels, reducing the risk of diabetes and hypoglycaemia.
- Improve flexibility and balance, reducing the risk of falling, especially in the elderly.
- Improve bone mineral density and therefore protect against osteoporosis and the risk of fractures. The exercise needs to be weight bearing to bring this benefit and so includes activities such as running, walking, games like tennis, golf, soccer etc and weight/resistance training.
- Improve immune function, increasing resistance to colds and flu.
- Improve digestion and bowel transit time, substantially reducing the risk of colon cancer.
- Keep our weight within a healthy range. People who exercise regularly have been shown to have better appetite control mechanisms and therefore do not overeat.
- Improve our sex life. Greater exercise is consistently linked to an improved sex life.
- Improve our self-esteem. Keeping fit and in shape helps us all feel better about ourselves.
- Increase our longevity. Exercise not only add years to our life, it also increases the number of years that we live without disease or disability. Starting an exercise programme at 65 can, on average add over 5 additional years of disability- and disease-free living. If we start at a younger age the benefits are even more significant.
If you are unfit it is important to start slowly and always warm up first with a few simple bends and stretches and some brisk walking or a gentle jog. The same must be done at the end of the exercise so that you cool down properly.
Quite simply, the more exercise you do the more you will be able to do – in more ways than one.