Ok, so we’re all aware of the ‘outside’ benefits of exercise... our clothes get loser, waists get smaller and muscles get bigger. But what’s happening on the inside? Why is exercise so heavily associated with health? And why should we take note? If you could add years onto your life, would you? Yes, it’s nice to drop a dress or trouser size but let’s have a look at the life-changing, physiological benefits of exercise... especially as we get older.
Benefits of Exercise... The Science
Exercise Lowers Hypertension
Now I’m sure most of you have heard that exercise lowers hypertension (high blood pressure) but what does that mean? Blood pressure refers to the pressure of circulating blood on the walls of blood vessels. Diastolic pressure (pressure when your heart rests between beats) rises with age and by as much as 10% between the ages of 60 & 70. Poor nutrition, sedentary lifestyle and high levels of stress increases the risk of high blood pressure. As a result, the heart has to pump harder than usual because of narrowed or constricted arteries.
According to clinical trials the best exercises are those that reduce the level of stress hormones in the bloodstream that constrict the arteries and veins. Progressive weightlifting, walking or jogging, stationary cycling have been found to lower blood pressure.
Exercise Improves Heart and Lung Fitness
The hearts function is to pump oxygenated blood around the body to the working muscles, organs and cells. The respiratory system provides the body with oxygen and removes carbon dioxide through a process called gaseous exchange that occurs in the alveoli. Studies show that the hearts ability to pump oxygenated blood around the body decreases by an average of 58% between 25-85 years of age and by 70, lung capacity can decrease by 40-50%.
Oxygen is needed for every cell in the body to function, so as the heart becomes less efficient with age, oxygen delivery also becomes less efficient. Exercise increases the size of the heart muscle (myocardium) enabling the left ventricle to stretch more and fill with more blood. An increase in stroke volume (amount of blood pumped per contraction) means the heart becomes more efficient and doesn’t have to work as hard to get blood around the body which in turn lowers the resting heart rate.
Exercise Improves Glucose Tolerance and Reduces Insulin Resistance
Exercise plays an important role in the improvement of the body’s glucose tolerance and insulin resistance - both key factors in the development of diabetes. Glucose tolerance is a measure of the body’s ability to metabolise glucose as it is released into the bloodstream, which usually declines with age.
People with type 2 diabetes have too much glucose in their blood, either because their body doesn’t produce enough insulin to process it, or because their body doesn’t use insulin properly (insulin resistant). In either case, increased muscular activity accelerates the transport of glucose into muscle cells regardless of the presence of insulin (i.e. muscles can use glucose without insulin). Therefore, exercise is a great tool for controlling type 2 diabetes and may even help prevent it in some cases. It may also prevent the serious complications of the disease.
Exercise Reduces Depression and Negative Moods
With ageing, a reduced cerebral blood flow causes a depletion of neurotransmitters, which could affect memory, attention span, concentration, and learning function. Depression is linked to the disturbance in the neurotransmitter’s; norepinephrine, serotonin and dopamine.
They all require oxygen for their synthesis and metabolism and regular endurance exercise is a great way to supply this oxygen to the brain.
Exercise Helps Maintain Bone Mass and Prevent Bone Loss
Bone is constantly being formed (process known as ossification) by cells called osteoblasts and reabsorbed by cells called osteoclasts throughout a person’s life. You gradually start losing bone density around the age of 35 and is a normal process, however some people develop osteoporosis and lose bone density faster than normal, increasing the risk of a fracture.
Women are more at risk of osteoporosis due to the change in hormones that occur during the menopause. The female hormone oestrogen is essential for healthy bones and as the menopause stops, oestrogen levels fall. In most cases, the cause of osteoporosis in men is unknown. There is a link to the male hormone testosterone, which helps keep bones healthy, so low levels of testosterone increase the risk of osteoporosis in men. Other risk factors could include family history, BMI of 19 or less, eating disorders, heavy drinking or smoking and long periods of inactivity.
Studies have shown exercise to stimulate bone mineralisation. Combing weight-bearing exercise with impact and muscle strengthening exercises proves to be most effective at keeping bones strong. Weight-bearing with impact involves being on your feet with additional force through your skeleton. This could consist of anything from walking, jogging, jumping and playing sport. Muscle strengthening exercises means you need to move your muscles against resistance, this could be with a weight, resistance band or your own body weight. It’s never too late to start exercising and trying to reverse the effect of osteoporosis. Incorporate vitamin D and calcium consumption along with a regular exercise regime.
Exercise Helps Maintain Joint Flexibility
As you age, the amount of fluid in the joints gradually deteriorates. Rheumatoid arthritis is the most common disorder of the joints and is caused by inflammation of the lining of the synovial capsule (tissue surrounding bones and cartilage).
Exercise helps to maintain cartilage, mineralise underlying bone, strengthen shock-absorbing muscles and ligaments around the joints and increase joint flexibility.