Exercising for heart health by Gareth Foot
You are probably aware by now that exercise is incredibly beneficial for your heart. But why is it so important to exercise, I mean there are plenty of older people that don’t seem to do much exercise. In 2006, cardiovascular disease (CVD) accounted for 34% (almost 46,000) of all deaths in Australia, with the disease killing one Australian nearly every 10 minutes. It affects 1 in 5 Australians and 2 in 3 families. Hopefully by the end of this article you will have a better understanding of some of the risk factors that are involved with CVD and how you can control some of them, because it is largely a preventable disease.
The risk factors for CVD can be broken up into two categories; modifiable and non-modifiable. These categories refer to risk factors that you can do something about (modifiable) and those you can’t (non-modifiable). Let’s start with the non-modifiable; if you are male, are increasing in age (i.e. the older you are, the higher your risk), being of Aboriginal or Torres Strait Islander descent and if you have a family history of CVD (the more immediate family members, the higher the risk). The modifiable risk factors can all be manipulated by your lifestyle and a reduction in these reduces your overall risk of CVD. Smoking (both active and passive), having high blood cholesterol or blood pressure, having diabetes, physical inactivity (not doing enough exercise), excessive alcohol, being overweight and depression/social isolation and a lack of social support. If you look at these modifiable risk factors, you can see that if you just improve your diet and get enough exercise, then you can positively affect almost all other risk factors (cholesterol, blood pressure, being overweight, physical inactivity, having diabetes, and being socially isolated). Ok so if you have one or more of these risk factors what starts to happen?
The heart is the pump that circulates all of the oxygenated blood around the body every few minutes. Being a muscle that is constantly contracting (between 50-210 beats per minute); the heart needs its own constant supply of oxygen. As a result of this, the heart has blood vessels that surround it (3 main ones branching into many smaller ones). This can be where the problems occur. Excess cholesterol or fat in the blood can clog up the arteries surrounding the heart. This is a gradual process which generally starts in your late twenties or early thirties and how quickly or slowly it progresses depends on your risk factors. This build up narrows the arteries, causing less blood to get through, resulting in the heart having to work harder to supply enough oxygen to the rest of the body and to get enough for its own needs.
Think about travelling down to the Gold Coast on the highway in a car; the highway is an artery that surrounds the heart and the cars are the blood cells carrying oxygen. It’s a nice wide highway and cars flow freely and quickly and they all get to where they need to go. Then as a result of the risk factors, fat builds up in the arteries (called a plaque); which is like road works being done so there is one less lane for a short distance. The cars still flow quite quickly and there is not much disturbance to the flow of traffic. But more fat is deposited and another lane on the highway is taken up, and then another. During the quiet times when there isn’t much traffic going down the highway (like when you are at rest) the traffic will still flow through freely. But eventually there is going to be an event that everyone is trying to get to the gold coast for (like when you exercise, there is an increased oxygen demand by the working muscles in the body and the heart), but due to the road works, a limited rate of people are getting past. It doesn’t matter how many signals the brain sends to get more blood through, there is a limit to the amount of cars able to get through.
The turbulence that the plaque causes in the blood flow may result in the plaque rupturing. When this happens, the ruptured plaque attracts things out of the blood that stick to it, like throwing a piece of chewing gum into sand, causing the blockage to grow in size dramatically. This may cause a partial blockage to become a complete one. This results in the heart cells becoming ischemic (a decrease in oxygen supply) and then they can infarct (becoming necrotic due to complete obstruction of the blood supply). Necrotic means dead and once cardiac cells die, you will NEVER get them back!!!
This, however, can be avoided by making a few small adjustments in your life. Exercising, improving diet, not drinking too much or smoking, all play a role in keeping the arteries around your heart nice and open. Exercise also has the beneficial effect of making your heart and other muscles in your body more efficient so that after you train them they require less oxygen from the blood to do the same amount of work. It also has the added benefit of opening new back streets around the highway arteries so that more blood can go down the backstreets to get to the same point, which also lowers your risk of a heart attack.
Small improvements in your exercise and diet habits can make a big difference. Small things like walking up the stairs at work, parking a bit further away from where you need to get to so that you walk a little further, walking the dog more and when you do, start going up some hills. Small changes in your diet such as: change something you have regularly consume to a healthier option (low fat milk, butter), trimming some of the fat from meat before you cook it, or choosing vegetables instead of chips for lunch. Every little thing you do counts so don’t worry if it feels daunting at the beginning, just start small and work from there. One of the best things about exercise is that it has what’s called a “dose-response” relationship. Basically it means that the lower your fitness is to begin with, the more improvement that you will get from it.
So start to make some small changes, to your life. The following points about changes will help you make your lifestyle better for the health of your heart:
• If you make them one at a time then they’re achievable.
• Think about climbing a mountain that has a cliff on one side and a gradual incline on the other. It seems almost impossible to climb up the cliff in one go, but it is much simpler to gently walk up the gradual incline and you’re more likely to reach the summit.
• Heart attacks are terrible things that cause drastic physical harm and psychological anguish that they can cause to the individual and their family and friends, if you survive them!!
• Talk to your GP about your risk for cardiovascular disease and get your blood tests done regularly. A high reading doesn’t mean a lot if you have no idea if it has improved or gotten worse. Remember the more you know about your personal health, the more you can detect small changes (positive or negative) and can make adjustments to your lifestyle to address them.
Once you make a few changes, you will start to feel/get healthier, sleep better, and have less stress in your life, as a result of lowering your overall risk of a cardiovascular event. Remember, you only have one heart, so look after it!! For more information, check out the Heart foundation website: http://www.heartfoundation.org.au or call on 1300 362 787.